PATENT DOCUMENT

Publication Number: US-11556201-B2
Application Number: US-202117381123-A
Country: US
Kind Code: B2

Title: Device, method, and user interface for processing intensity of touch contacts

Abstract:
An electronic device, in response to detecting a touch input on a touch-sensitive surface, determines an intensity of the touch input. In accordance with the intensity of the touch input on the touch-sensitive surface and one or more preselected intensity thresholds, the device determines an intensity stage of the touch input and one or more intensity-based progress values of the touch input, based on an intensity range associated with the determined intensity stage. The device sends touch information to a first software application stored by the electronic device, including the one or more intensity-based progress values of the touch input and information identifying the intensity stage of the touch input, and processes the touch input based on the one or more intensity-based progress values of the touch input and the intensity stage of the touch input.

Claims:
What is claimed is: 
     
       1. A method, comprising:
 at an electronic device with a touch-sensitive surface, wherein the touch-sensitive surface includes one or more sensors to detect intensity of contacts with the touch-sensitive surface:
 detecting a touch input on the touch-sensitive surface; 
 in response to detecting the touch input on the touch-sensitive surface, determining an intensity of the touch input on the touch-sensitive surface; 
 in accordance with the intensity of the touch input on the touch-sensitive surface and one or more preselected intensity thresholds, determining an intensity stage of the touch input, wherein the intensity stage of the touch input is selected from a plurality of predefined intensity stages; 
 determining one or more intensity-based progress values of the touch input based on an intensity range associated with the determined intensity stage; 
 sending touch information to a first software application stored by the electronic device, wherein the touch information includes the one or more intensity-based progress values of the touch input and information identifying the intensity stage of the touch input; and 
 processing the touch information, corresponding to the touch input, by the first software application based on the one or more intensity-based progress values of the touch input and the intensity stage of the touch input to produce output corresponding to the touch input. 
 
 
     
     
       2. The method of  claim 1 , wherein the intensity stage of the touch input is determined by a contact intensity module that is distinct and separate from the first software application. 
     
     
       3. The method of  claim 2 , including displaying a user interface, while displaying the user interface receiving the touch input, sending to the first software application from the contact intensity module touch information that identifies the intensity stage of the touch input, and updating the user interface in accordance with at least the intensity stage of the touch input. 
     
     
       4. The method of  claim 3 , including sending information from the contact intensity module, the information indicating that the intensity of the touch input is available to the first software application. 
     
     
       5. The method of  claim 3 , including:
 while the touch input continues to be detected on the touch-sensitive surface, repeating the operations of determining an intensity of the touch input, determining an intensity stage of the touch input, and sending touch information. 
 
     
     
       6. The method of  claim 3 , including:
 in response to detecting the touch input, determining a first intensity applied by the touch input on the touch-sensitive surface; 
 in accordance with a determination that the first intensity applied by the touch input on the touch-sensitive surface does not satisfy a stage activation intensity threshold for a second intensity stage, determining that the touch input is in a first intensity stage that is distinct from the second intensity stage; 
 subsequent to determining that the touch input is in the first intensity stage, determining a second intensity applied by the touch input on the touch-sensitive surface, wherein the second intensity is distinct from the first intensity; and 
 in accordance with a determination that the second intensity applied by the touch input on the touch-sensitive surface satisfies the stage activation intensity threshold for the second intensity stage, determining that the touch input is in the second intensity stage. 
 
     
     
       7. The method of  claim 6 , including:
 subsequent to determining that the touch input is in the second intensity stage, determining a third intensity applied by the touch input on the touch-sensitive surface, wherein the third intensity is distinct from the second intensity; 
 in accordance with a determination that the third intensity does not satisfy a stage release intensity threshold for the second intensity stage, distinct from the stage activation intensity threshold for the second intensity stage, determining that the touch input remains in the second intensity stage; 
 subsequent to determining that the touch input remains in the second intensity stage, determining a fourth intensity applied by the touch input on the touch-sensitive surface, wherein the fourth intensity is distinct from the third intensity; and 
 in accordance with a determination that the fourth intensity satisfies the stage release intensity threshold for the second intensity stage, determining that the touch input is in the first intensity stage. 
 
     
     
       8. The method of  claim 6 , including:
 subsequent to determining that the touch input remains in the second intensity stage, determining a third intensity applied by the touch input on the touch-sensitive surface, wherein the third intensity is distinct from the second intensity; and 
 in accordance with a determination that the third intensity satisfies a stage activation threshold for a third intensity stage, distinct from the stage activation intensity threshold for the second intensity stage, determining that the touch input is in the third intensity stage. 
 
     
     
       9. The method of  claim 8 , including:
 subsequent to determining that the touch input is in the third intensity stage, determining a fourth intensity applied by the touch input on the touch-sensitive surface, wherein the fourth intensity is distinct from the third intensity; and 
 in accordance with a determination that the fourth intensity satisfies a stage release intensity threshold for the third intensity stage, distinct from the stage activation threshold for the third intensity stage, determining that the touch input is in the second intensity stage. 
 
     
     
       10. The method of  claim 1 , including:
 identifying an intensity model identifier from a plurality of predefined intensity model identifiers, wherein the intensity stage of the touch input is selected from a plurality of intensity stages that correspond to the identified intensity model identifier. 
 
     
     
       11. The method of  claim 1 , wherein the one or more intensity-based progress values of the touch input include a transition progress value of the touch input or a stage progress value of the touch input. 
     
     
       12. The method of  claim 1 , wherein processing the touch information by the first software application includes updating a user interface. 
     
     
       13. An electronic device, comprising:
 a touch-sensitive surface; 
 one or more sensors to detect intensity of contacts with the touch-sensitive surface; 
 one or more processors; and 
 memory storing one or more programs, wherein the one or more programs are configured to be executed by the one or more processors, the one or more programs including instructions for:
 detecting a touch input on the touch-sensitive surface; 
 in response to detecting the touch input on the touch-sensitive surface, determining an intensity of the touch input on the touch-sensitive surface; 
 in accordance with the intensity of the touch input on the touch-sensitive surface and one or more preselected intensity thresholds, determining an intensity stage of the touch input, wherein the intensity stage of the touch input is selected from a plurality of predefined intensity stages; 
 determining one or more intensity-based progress values of the touch input based on an intensity range associated with the determined intensity stage; 
 sending touch information to a first software application stored by the electronic device, wherein the touch information includes the one or more intensity-based progress values of the touch input and information identifying the intensity stage of the touch input; and 
 processing the touch information, corresponding to the touch input, by the first software application based on the one or more intensity-based progress values of the touch input and the intensity stage of the touch input to produce output corresponding to the touch input. 
 
 
     
     
       14. The electronic device of  claim 13 , wherein the intensity stage of the touch input is determined by a contact intensity module that is distinct and separate from the first software application. 
     
     
       15. The electronic device of  claim 14 , wherein the one or more programs include instructions for: displaying a user interface, while displaying the user interface receiving the touch input, sending to the first software application from the contact intensity module touch information that identifies the intensity stage of the touch input, and updating the user interface in accordance with at least the intensity stage of the touch input. 
     
     
       16. The electronic device of  claim 15 , wherein the one or more programs include instructions for sending information from the contact intensity module, the information indicating that the intensity of the touch input is available to the first software application. 
     
     
       17. The electronic device of  claim 15 , wherein the one or more programs include instructions for:
 while the touch input continues to be detected on the touch-sensitive surface, repeating the operations of determining an intensity of the touch input, determining an intensity stage of the touch input, and sending touch information. 
 
     
     
       18. The electronic device of  claim 15 , wherein the one or more programs include instructions for:
 in response to detecting the touch input, determining a first intensity applied by the touch input on the touch-sensitive surface; 
 in accordance with a determination that the first intensity applied by the touch input on the touch-sensitive surface does not satisfy a stage activation intensity threshold for a second intensity stage, determining that the touch input is in a first intensity stage that is distinct from the second intensity stage; 
 subsequent to determining that the touch input is in the first intensity stage, determining a second intensity applied by the touch input on the touch-sensitive surface, wherein the second intensity is distinct from the first intensity; and 
 in accordance with a determination that the second intensity applied by the touch input on the touch-sensitive surface satisfies the stage activation intensity threshold for the second intensity stage, determining that the touch input is in the second intensity stage. 
 
     
     
       19. The electronic device of  claim 18 , wherein the one or more programs include instructions for:
 subsequent to determining that the touch input is in the second intensity stage, determining a third intensity applied by the touch input on the touch-sensitive surface, wherein the third intensity is distinct from the second intensity; 
 in accordance with a determination that the third intensity does not satisfy a stage release intensity threshold for the second intensity stage, distinct from the stage activation intensity threshold for the second intensity stage, determining that the touch input remains in the second intensity stage; 
 subsequent to determining that the touch input remains in the second intensity stage, determining a fourth intensity applied by the touch input on the touch-sensitive surface, wherein the fourth intensity is distinct from the third intensity; and 
 in accordance with a determination that the fourth intensity satisfies the stage release intensity threshold for the second intensity stage, determining that the touch input is in the first intensity stage. 
 
     
     
       20. The electronic device of  claim 18 , wherein the one or more programs include instructions for:
 subsequent to determining that the touch input remains in the second intensity stage, determining a third intensity applied by the touch input on the touch-sensitive surface, wherein the third intensity is distinct from the second intensity; and 
 in accordance with a determination that the third intensity satisfies a stage activation threshold for a third intensity stage, distinct from the stage activation intensity threshold for the second intensity stage, determining that the touch input is in the third intensity stage. 
 
     
     
       21. The electronic device of  claim 20 , wherein the one or more programs include instructions for:
 subsequent to determining that the touch input is in the third intensity stage, determining a fourth intensity applied by the touch input on the touch-sensitive surface, wherein the fourth intensity is distinct from the third intensity; and 
 in accordance with a determination that the fourth intensity satisfies a stage release intensity threshold for the third intensity stage, distinct from the stage activation threshold for the third intensity stage, determining that the touch input is in the second intensity stage. 
 
     
     
       22. The electronic device of  claim 13 , wherein the one or more programs include instructions for:
 identifying an intensity model identifier from a plurality of predefined intensity model identifiers, wherein the intensity stage of the touch input is selected from a plurality of intensity stages that correspond to the identified intensity model identifier. 
 
     
     
       23. The electronic device of  claim 13 , wherein the one or more intensity-based progress values of the touch input include a transition progress value of the touch input or a stage progress value of the touch input. 
     
     
       24. The electronic device of  claim 13 , wherein processing the touch information by the first software application includes updating a user interface. 
     
     
       25. A non-transitory computer readable storage medium storing one or more programs, the one or more programs including instructions, which, when executed by an electronic device with a touch-sensitive surface and one or more sensors to detect intensity of contacts with the touch-sensitive surface, cause the electronic device to:
 detect a touch input on the touch-sensitive surface; 
 in response to detecting the touch input on the touch-sensitive surface, determine an intensity of the touch input on the touch-sensitive surface; 
 in accordance with the intensity of the touch input on the touch-sensitive surface and one or more preselected intensity thresholds, determine an intensity stage of the touch input, wherein the intensity stage of the touch input is selected from a plurality of predefined intensity stages; 
 determine one or more intensity-based progress values of the touch input based on an intensity range associated with the determined intensity stage; 
 send touch information to a first software application stored by the electronic device, wherein the touch information includes the one or more intensity-based progress values of the touch input and information identifying the intensity stage of the touch input; and 
 processing the touch information, corresponding to the touch input, by the first software application based on the one or more intensity-based progress values of the touch input and the intensity stage of the touch input to produce output corresponding to the touch input. 
 
     
     
       26. The non-transitory computer readable storage medium of  claim 25 , wherein the intensity stage of the touch input is determined by a contact intensity module that is distinct and separate from the first software application. 
     
     
       27. The non-transitory computer readable storage medium of  claim 26 , wherein the one or more programs include instructions, which, when executed by the electronic device, cause the electronic device to: display a user interface, while displaying the user interface receive the touch input, send to the first software application from the contact intensity module touch information that identifies the intensity stage of the touch input, and update the user interface in accordance with at least the intensity stage of the touch input. 
     
     
       28. The non-transitory computer readable storage medium of  claim 27  wherein the one or more programs include instructions, which, when executed by the electronic device, cause the electronic device to: send information from the contact intensity module, the information indicating that the intensity of the touch input is available to the first software application. 
     
     
       29. The non-transitory computer readable storage medium of  claim 27 , wherein the one or more programs include instructions, which, when executed by the electronic device, cause the electronic device to: while the touch input continues to be detected on the touch-sensitive surface, repeat the operations of determining an intensity of the touch input, determining an intensity stage of the touch input, and sending touch information. 
     
     
       30. The non-transitory computer readable storage medium of  claim 27 , wherein the one or more programs include instructions, which, when executed by the electronic device, cause the electronic device:
 detect the touch input, in response to detecting the touch input, determine a first intensity applied by the touch input on the touch-sensitive surface; 
 in accordance with a determination that the first intensity applied by the touch input on the touch-sensitive surface does not satisfy a stage activation intensity threshold for a second intensity stage, determine that the touch input is in a first intensity stage that is distinct from the second intensity stage; 
 subsequent to determining that the touch input is in the first intensity stage, determine a second intensity applied by the touch input on the touch-sensitive surface, wherein the second intensity is distinct from the first intensity; and 
 in accordance with a determination that the second intensity applied by the touch input on the touch-sensitive surface satisfies the stage activation intensity threshold for the second intensity stage, determine that the touch input is in the second intensity stage. 
 
     
     
       31. The non-transitory computer readable storage medium of  claim 30 , wherein the one or more programs include instructions, which, when executed by the electronic device, cause the electronic device to:
 subsequent to determining that the touch input is in the second intensity stage, determine a third intensity applied by the touch input on the touch-sensitive surface, wherein the third intensity is distinct from the second intensity; 
 in accordance with a determination that the third intensity does not satisfy a stage release intensity threshold for the second intensity stage, distinct from the stage activation intensity threshold for the second intensity stage, determine that the touch input remains in the second intensity stage; 
 subsequent to determining that the touch input remains in the second intensity stage, determine a fourth intensity applied by the touch input on the touch-sensitive surface, wherein the fourth intensity is distinct from the third intensity; and 
 in accordance with a determination that the fourth intensity satisfies the stage release intensity threshold for the second intensity stage, determine that the touch input is in the first intensity stage. 
 
     
     
       32. The non-transitory computer readable storage medium of  claim 30 , wherein the one or more programs include instructions, which, when executed by the electronic device, cause the electronic device to:
 subsequent to determining that the touch input remains in the second intensity stage, determine a third intensity applied by the touch input on the touch-sensitive surface, wherein the third intensity is distinct from the second intensity; and 
 in accordance with a determination that the third intensity satisfies a stage activation threshold for a third intensity stage, distinct from the stage activation intensity threshold for the second intensity stage, determine that the touch input is in the third intensity stage. 
 
     
     
       33. The non-transitory computer readable storage medium of  claim 32 , including:
 subsequent to determining that the touch input is in the third intensity stage, determine a fourth intensity applied by the touch input on the touch-sensitive surface, wherein the fourth intensity is distinct from the third intensity; and 
 in accordance with a determination that the fourth intensity satisfies a stage release intensity threshold for the third intensity stage, distinct from the stage activation threshold for the third intensity stage, determine that the touch input is in the second intensity stage. 
 
     
     
       34. The non-transitory computer readable storage medium of  claim 30 , wherein the one or more programs include instructions, which, when executed by the electronic device, cause the electronic device to:
 identify an intensity model identifier from a plurality of predefined intensity model identifiers, wherein the intensity stage of the touch input is selected from a plurality of intensity stages that correspond to the identified intensity model identifier. 
 
     
     
       35. The non-transitory computer readable storage medium of  claim 25 , wherein the one or more intensity-based progress values of the touch input include a transition progress value of the touch input or a stage progress value of the touch input. 
     
     
       36. The non-transitory computer readable storage medium of  claim 25 , wherein processing the touch information by the first software application includes updating a user interface.

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/784,192, filed Feb. 6, 2020, which is a continuation of U.S. application Ser. No. 16/031,974, filed Jul. 10, 2018, now U.S. Pat. No. 10,558,268, which is a continuation of U.S. application Ser. No. 15/488,096, filed Apr. 14, 2017, now U.S. Pat. No. 10,019,065, which is a continuation of U.S. application Ser. No. 14/869,225, filed Sep. 29, 2015, now U.S. Pat. No. 9,645,669, which is a continuation of U.S. patent application Ser. No. 14/868,285, filed Sep. 28, 2015, now U.S. Pat. No. 9,542,037, which claims priority to U.S. Provisional Patent Application Ser. No. 62/129,937, filed Mar. 8, 2015, all of which are incorporated by reference herein in their entireties. 
    
    
     TECHNICAL FIELD 
     This relates generally to electronic devices with touch-sensitive surfaces, including but not limited to electronic devices with touch-sensitive surfaces and sensors to detect intensity of contacts on the touch-sensitive surfaces. 
     BACKGROUND 
     The use of touch-sensitive surfaces as input devices for computers and other electronic computing devices has increased significantly in recent years. Exemplary touch-sensitive surfaces include touchpads and touch-screen displays. Such surfaces are widely used to manipulate user interface objects on a display. 
     In addition to the presence or absence of a contacts (or touches) on the touchpads and touch-screen displays, intensity of contacts can be used to manipulate user interface objects on a display. 
     However, processing intensity of contacts can be cumbersome and inefficient. For example, processing intensity of contacts require complex instructions, which can lead to increased computational load, increased size of software applications, and increased power consumption. These create a significant burden on the use of intensity of contacts in electronic devices. 
     SUMMARY 
     Accordingly, there is a need for electronic devices with faster, more efficient methods and interfaces for processing touch inputs. Such methods and interfaces optionally complement or replace conventional methods for processing touch inputs. Such methods and interfaces reduce the number, extent, and/or nature of the inputs from a user and produce a more efficient human-machine interface. For battery-operated devices, such methods and interfaces conserve power and increase the time between battery charges. 
     The above deficiencies and other problems associated with user interfaces for electronic devices with touch-sensitive surfaces are reduced or eliminated by the disclosed devices. In some embodiments, the device is a desktop computer. In some embodiments, the device is portable (e.g., a notebook computer, tablet computer, or handheld device). In some embodiments, the device is a personal electronic device (e.g., a wearable electronic device, such as a watch). In some embodiments, the device has a touchpad. In some embodiments, the device has a touch-sensitive display (also known as a “touch screen” or “touch-screen display”). In some embodiments, the device has a graphical user interface (GUI), one or more processors, memory and one or more modules, programs or sets of instructions stored in the memory for performing multiple functions. In some embodiments, the user interacts with the GUI primarily through stylus and/or finger contacts and gestures on the touch-sensitive surface. In some embodiments, the functions optionally include image editing, drawing, presenting, word processing, spreadsheet making, game playing, telephoning, video conferencing, e-mailing, instant messaging, workout support, digital photographing, digital videoing, web browsing, digital music playing, note taking, and/or digital video playing. Executable instructions for performing these functions are, optionally, included in a non-transitory computer readable storage medium or other computer program product configured for execution by one or more processors. 
     In accordance with some embodiments, a method is performed at an electronic device with a touch-sensitive surface and one or more sensors to detect intensity of contacts with the touch-sensitive surface. The method includes: detecting a touch input on the touch-sensitive surface; in response to detecting the touch input on the touch-sensitive surface, determining an intensity of the touch input on the touch-sensitive surface; and, in accordance with the intensity of the touch input on the touch-sensitive surface and one or more preselected intensity thresholds, determining an intensity stage of the touch input. The intensity stage of the touch input is selected from a plurality of predefined intensity stages. The method also includes processing the touch input based on the intensity stage of the touch input. 
     In accordance with some embodiments, a method is performed at an electronic device with a touch-sensitive surface and one or more sensors to detect intensity of contacts with the touch-sensitive surface. The electronic device stores a first software application. The method includes: detecting a first touch input on the touch-sensitive surface; in response to detecting the first touch input on the touch-sensitive surface, determining a first intensity applied by the first touch input on the touch-sensitive surface; identifying a first intensity model identifier from a plurality of predefined intensity model identifiers; in accordance with the first intensity applied by the first touch input on the touch-sensitive surface and one or more thresholds associated with the first intensity model identifier, determining a first touch characterization parameter; and, subsequent to determining the first touch characterization parameter, sending first touch information to the first software application. The first touch information includes the first intensity model identifier and the first touch characterization parameter. 
     In accordance with some embodiments, a method is performed at an electronic device with a touch-sensitive surface and one or more sensors to detect intensity of contacts with the touch-sensitive surface. The electronic device stores a first software application. The method includes: detecting a first touch input on a first touch region of the touch-sensitive surface; identifying a first intensity model identifier, associated with the first touch region of the touch-sensitive surface, from a plurality of predefined intensity model identifiers; in response to detecting the first touch input on the first touch region of the touch-sensitive surface: determining a first intensity applied by the first touch input on the first touch region of the touch-sensitive surface; in accordance with the first intensity applied by the first touch input on the touch-sensitive surface and one or more thresholds associated with the first intensity model identifier, determining a first touch characterization parameter; and, subsequent to determining the first touch characterization parameter, sending first touch information to the first software application. The first touch information includes the first touch characterization parameter. The method also includes detecting a second touch input on a second touch region of the touch-sensitive surface. The second touch region of the touch-sensitive surface is distinct from the first touch region of the touch-sensitive surface. The method further includes identifying a second intensity model identifier, associated with the second touch region of the touch-sensitive surface, from the plurality of predefined intensity model identifiers; and, in response to detecting the second touch input on the second touch region of the touch-sensitive surface: determining a second intensity applied by the second touch input on the second touch region of the touch-sensitive surface; in accordance with the second intensity applied by the second touch input on the touch-sensitive surface and one or more thresholds associated with the second intensity model identifier, determining a second touch characterization parameter; and, subsequent to determining the second touch characterization parameter, sending second touch information to the first software application. The second touch information includes the second touch characterization parameter. 
     In accordance with some embodiments, a method is performed at an electronic device with a touch-sensitive surface and one or more sensors to detect intensity of contacts with the touch-sensitive surface. The method includes: detecting a touch input on the touch-sensitive surface; and, in response to detecting the touch input: in accordance with a determination that the touch input is at a location on the touch-sensitive surface that is associated with a first intensity model of a plurality of different intensity models, processing the touch input in accordance with an intensity applied by the touch input on the touch-sensitive surface and the first intensity model; and, in accordance with a determination that the touch input is at a location on the touch-sensitive surface that is associated with a second intensity model different from the first intensity model, processing the touch input in accordance with an intensity applied by the touch input on the touch-sensitive surface and the second intensity model. 
     In accordance with some embodiments, a method is performed at an electronic device with a display, a touch-sensitive surface, and one or more sensors to detect intensity of contacts with the touch-sensitive surface. The electronic device stores a first software application. The method includes: displaying a user interface that includes two or more display regions, including a first display region and a second display region; and, while displaying the user interface: detecting a first intensity applied by a touch input at a first location on the touch-sensitive surface that corresponds to the first display region; detecting a movement of the touch input across the touch-sensitive surface from the first location on the touch-sensitive surface to a second location on the touch-sensitive surface that corresponds to the second display region; after detecting the movement of the touch input from the first location on the touch-sensitive surface to the second location on the touch-sensitive surface, detecting a second intensity applied by the touch input at the second location on the touch-sensitive surface; and, in response to detecting the second intensity applied by the touch input at the second location on the touch-sensitive surface: in accordance with a determination that the first intensity does not satisfy a first intensity threshold, processing the second intensity in accordance with one or more intensity thresholds associated with the second display region; and, in accordance with a determination that the first intensity satisfies the first intensity threshold, processing the second intensity in accordance with one or more intensity thresholds associated with the first display region. 
     In accordance with some embodiments, a method is performed at an electronic device in communication with a plurality of input devices including a first input device that is configured to generate tactile outputs in response to inputs and a second input device that is configured to generate tactile outputs. The method includes receiving an indication of an input detected by a respective input device of the plurality of input devices, and in response to receiving the indication of the input, providing information describing the input to an application running on the device that enables the application to react to the input. The method further includes receiving a reaction to the input from the application that indicates that a tactile output is to be generated in response to the input, and in response to receiving the reaction to the input from the application, causing the generation of a respective tactile output. In accordance with a determination that the reaction was triggered by the first input device, the respective tactile output is generated at the first input device based on the reaction to the input from the application, and in accordance with a determination that the reaction was triggered by the second input device, the respective tactile output is generated at the second input device based on the reaction to the input from the application. 
     In accordance with some embodiments, an electronic device includes a display, a first input device that is configured to generate tactile outputs in response to inputs, a second input device that is configured to generate tactile outputs, one or more processors, memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors. The one or more programs including instructions for receiving an indication of an input detected by a respective input device of the plurality of input devices, and in response to receiving the indication of the input, providing information describing the input to an application running on the device that enables the application to react to the input. The one or more programs further include instructions for receiving a reaction to the input from the application that indicates that a tactile output is to be generated in response to the input, and in response to receiving the reaction to the input from the application, causing the generation of a respective tactile output. In accordance with a determination that the reaction was triggered by the first input device, the respective tactile output is generated at the first input device based on the reaction to the input from the application, and in accordance with a determination that the reaction was triggered by the second input device, the respective tactile output is generated at the second input device based on the reaction to the input from the application. 
     In accordance with some embodiments, a non-transitory computer readable storage medium stores one or more programs, the one or more programs comprising instructions, which when executed by an electronic device having a display, a first input device that is configured to generate tactile outputs in response to inputs, and a second input device that is configured to generate tactile outputs, cause the device to perform the aforementioned method, or any of the other methods described herein. 
     In accordance with some embodiments, a method is performed at an electronic device in communication with one or more input devices that are configured to generate tactile outputs in response to inputs. The method includes receiving an indication of an input detected by a respective input device of the one or more input devices, and in response to receiving the indication of the input, providing information describing the input to an application running on the device that enables the application to react to the input. The method further includes receiving a reaction to the input from the application that indicates that a tactile output is to be generated in response to the input. In response to receiving the reaction to the input from the application, the electronic device performs a set of operations, including comparing an input time for the reaction to an output time for the reaction. With respect to the comparing, the input time for the reaction corresponds to a time at which the input was detected by the respective input device, and the output time for the reaction corresponds to a time at which a tactile output corresponding to the reaction is configured to be generated at the respective input device. The set of operations performed in response to receiving the reaction to the input from the application further includes determining whether tactile output criteria have been met, wherein the tactile output criteria include a criterion that is met when an input time is less than a predetermined amount of time before the output time, and in accordance with a determination that the tactile output criteria have been met, causing generation, at the respective input device, of a tactile output corresponding to the reaction from the application. On the other hand, the set of operations performed in response to receiving the reaction to the input from the application includes, in accordance with a determination that the tactile output criteria have not been met, forgoing generation, at the respective input device, of the tactile output corresponding to the reaction from the application. 
     In accordance with some embodiments, an electronic device includes a display, one or more input devices that are configured to generate tactile outputs in response to inputs, one or more processors, memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors. The one or more programs including instructions for receiving an indication of an input detected by a respective input device of the one or more input devices, and in response to receiving the indication of the input, providing information describing the input to an application running on the device that enables the application to react to the input. The one or more programs further include instructions for receiving a reaction to the input from the application that indicates that a tactile output is to be generated in response to the input, and in response to receiving the reaction to the input from the application, performing a set of operations, including comparing an input time for the reaction to an output time for the reaction. With respect to the comparing, the input time for the reaction corresponds to a time at which the input was detected by the respective input device, and the output time for the reaction corresponds to a time at which a tactile output corresponding to the reaction is configured to be generated at the respective input device. The set of operations performed in response to receiving the reaction to the input from the application further includes determining whether tactile output criteria have been met, wherein the tactile output criteria include a criterion that is met when an input time is less than a predetermined amount of time before the output time, and in accordance with a determination that the tactile output criteria have been met, causing generation, at the respective input device, of a tactile output corresponding to the reaction from the application. On the other hand, the set of operations performed in response to receiving the reaction to the input from the application includes, in accordance with a determination that the tactile output criteria have not been met, forgoing generation, at the respective input device, of the tactile output corresponding to the reaction from the application. 
     In accordance with some embodiments, a non-transitory computer readable storage medium stores one or more programs, the one or more programs comprising instructions, which when executed by an electronic device having a display, one or more input devices that are configured to generate tactile outputs in response to inputs, cause the device to perform the aforementioned method, or any of the other methods described herein. 
     In accordance with some embodiments, an electronic device includes a touch-sensitive surface unit to receive contacts, one or more sensor units to detect intensity of contacts with the touch-sensitive surface unit; and a processing unit coupled with the touch-sensitive surface unit and the one or more sensor units. The processing unit is configured to: detect a touch input on the touch-sensitive surface unit; in response to detecting the touch input on the touch-sensitive surface unit, determine an intensity of the touch input on the touch-sensitive surface unit; in accordance with the intensity of the touch input on the touch-sensitive surface unit and one or more preselected intensity thresholds, determine an intensity stage of the touch input, wherein the intensity stage of the touch input is selected from a plurality of predefined intensity stages; and process the touch input based on the intensity stage of the touch input. 
     In accordance with some embodiments, an electronic device includes a touch-sensitive surface unit to receive contacts, one or more sensor units to detect intensity of contacts with the touch-sensitive surface unit; and a processing unit coupled with the touch-sensitive surface unit and the one or more sensor units. The processing unit is configured to: detect a first touch input on the touch-sensitive surface unit; in response to detecting the first touch input on the touch-sensitive surface unit, determine a first intensity applied by the first touch input on the touch-sensitive surface unit; identify a first intensity model identifier from a plurality of predefined intensity model identifiers; in accordance with the first intensity applied by the first touch input on the touch-sensitive surface unit and one or more thresholds associated with the first intensity model identifier, determine a first touch characterization parameter; and, subsequent to determining the first touch characterization parameter, send first touch information to a first software application, wherein the first touch information includes the first intensity model identifier and the first touch characterization parameter. 
     In accordance with some embodiments, an electronic device includes a display unit configured to display a touch-sensitive surface unit to receive contacts, one or more sensor units to detect intensity of contacts with the touch-sensitive surface unit; and a processing unit coupled with the touch-sensitive surface unit and the one or more sensor units. The processing unit is configured to: detect a first touch input on a first touch region of the touch-sensitive surface unit; identify a first intensity model identifier, associated with the first touch region of the touch-sensitive surface unit, from a plurality of predefined intensity model identifiers; and, in response to detecting the first touch input on the first touch region of the touch-sensitive surface unit: determine a first intensity of the first touch input on the first touch region of the touch-sensitive surface unit; in accordance with the first intensity applied by the first touch input on the touch-sensitive surface unit and one or more thresholds associated with the first intensity model identifier, determine a first touch characterization parameter; and, subsequent to determining the first touch characterization parameter, send first touch information to a first software application, wherein the first touch information includes the first touch characterization parameter. The processing unit is also configured to: detect a second touch input on a second touch region of the touch-sensitive surface unit, wherein the second touch region of the touch-sensitive surface unit is distinct from the first touch region of the touch-sensitive surface unit; identify a second intensity model identifier, associated with the second touch region of the touch-sensitive surface unit, from the plurality of predefined intensity model identifiers; and, in response to detecting the second touch input on the second touch region of the touch-sensitive surface unit: determine a second intensity applied by the second touch input on the second touch region of the touch-sensitive surface unit; in accordance with the second intensity applied by the second touch input on the touch-sensitive surface unit and one or more thresholds associated with the second intensity model identifier, determine a second touch characterization parameter; and, subsequent to determining the second touch characterization parameter, send second touch information to the first software application, wherein the second touch information includes the second touch characterization parameter. 
     In accordance with some embodiments, an electronic device includes a touch-sensitive surface unit to receive contacts, one or more sensor units to detect intensity of contacts with the touch-sensitive surface unit; and a processing unit coupled with the touch-sensitive surface unit and the one or more sensor units. The processing unit is configured to: detect a touch input on the touch-sensitive surface unit; and, in response to detecting the touch input: in accordance with a determination that the touch input is at a location on the touch-sensitive surface unit that is associated with a first intensity model of a plurality of different intensity models, processing the touch input in accordance with an intensity applied by the touch input on the touch-sensitive surface unit and the first intensity model; and, in accordance with a determination that the touch input is at a location on the touch-sensitive surface unit that is associated with a second intensity model different from the first intensity model, processing the touch input in accordance with an intensity applied by the touch input on the touch-sensitive surface unit and the second intensity model. 
     In accordance with some embodiments, an electronic device includes a display unit configured to display a user interface, a touch-sensitive surface unit to receive contacts, one or more sensor units to detect intensity of contacts with the touch-sensitive surface unit; and a processing unit coupled with the display unit, the touch-sensitive surface unit, and the one or more sensor units. The processing unit is configured to: enable display of a user interface that includes two or more display regions, including a first display region and a second display region on the display unit; and, while displaying the user interface: detect a first intensity applied by a touch input at a first location on the touch-sensitive surface unit that corresponds to the first display region; detect a movement of the touch input across the touch-sensitive surface unit from the first location on the touch-sensitive surface unit to a second location on the touch-sensitive surface unit that corresponds to the second display region; after detecting the movement of the touch input from the first location on the touch-sensitive surface unit to the second location on the touch-sensitive surface unit, detect a second intensity applied by the touch input at the second location on the touch-sensitive surface unit; and, in response to detecting the second intensity applied by the touch input at the second location on the touch-sensitive surface unit: in accordance with a determination that the first intensity does not satisfy a first intensity threshold, process the second intensity in accordance with one or more intensity thresholds associated with the second display region; and, in accordance with a determination that the first intensity satisfies the first intensity threshold, process the second intensity in accordance with one or more intensity thresholds associated with the first display region. 
     In accordance with some embodiments, an electronic device includes a display unit configured to display a user interface and a plurality of input units, including a first input unit that is configured to generate tactile outputs in response to inputs, and a second input unit that is configured to generate tactile outputs. The electronic device further includes an input indication receiving unit configured to receive an indication of an input detected by a respective input unit of the plurality of input units, and an information providing unit configured to provide, in response to receiving the indication of the input, information describing the input to an application running on the electronic device that enables the application to react to the input. The electronic device further includes a reaction receiving unit configured to receive a reaction to the input from the application that indicates that a tactile output is to be generated in response to the input, and a causing unit configured to cause, in response to receiving the reaction to the input from the application, the generation of a respective tactile output. In accordance with a determination that the reaction was triggered by the first input unit, the respective tactile output is generated at the first input unit based on the reaction to the input from the application, and in accordance with a determination that the reaction was triggered by the second input unit, the respective tactile output is generated at the second input unit based on the reaction to the input from the application. 
     In accordance with some embodiments, an electronic device includes a display unit configured to display a user interface hierarchy and one or more input units that are configured to generate tactile outputs in response to inputs. The electronic device further includes an input indication receiving unit configured to receive an indication of an input detected by a respective input unit of the one or more input units, and an information providing unit configured to provide, in response to receiving the indication of the input, information describing the input to an application running on the electronic device that enables the application to react to the input. The electronic device further includes a reaction receiving unit configured to receive a reaction to the input from the application that indicates that a tactile output is to be generated in response to the input, and a causing unit configured to cause, in response to receiving the reaction to the input from the application, the performance of a set of operations, including comparing an input time for the reaction to an output time for the reaction. With respect to the comparing, the input time for the reaction corresponds to a time at which the input was detected by the respective input device, and the output time for the reaction corresponds to a time at which a tactile output corresponding to the reaction is configured to be generated at the respective input device. The set of operations performed in response to receiving the reaction to the input from the application further includes determining whether tactile output criteria have been met, wherein the tactile output criteria include a criterion that is met when an input time is less than a predetermined amount of time before the output time, and in accordance with a determination that the tactile output criteria have been met, causing generation, at the respective input device, of a tactile output corresponding to the reaction from the application. On the other hand, the set of operations performed in response to receiving the reaction to the input from the application includes, in accordance with a determination that the tactile output criteria have not been met, forgoing generation, at the respective input device, of the tactile output corresponding to the reaction from the application. 
     In accordance with some embodiments, an electronic device includes a touch-sensitive surface, one or more sensors to detect intensity of contacts with the touch-sensitive surface, optionally a display, one or more processors, and memory. The memory stores one or more programs that are configured to be executed by the one or more processors. The one or more programs include instructions for performing or causing performance of the operations of any of the methods described herein. In accordance with some embodiments, a computer readable storage medium stores therein instructions, which, when executed by an electronic device with a touch-sensitive surface and one or more sensors to detect intensity of contacts with the touch-sensitive surface, cause the device to perform or cause performance of the operations of any of the methods described herein. In accordance with some embodiments, a graphical user interface on an electronic device with a display, a touch-sensitive surface, one or more sensors to detect intensity of contacts with the touch-sensitive surface, a memory, and one or more processors to execute one or more programs stored in the memory includes one or more of the elements displayed in any of the methods described herein, which are updated in response to inputs, as described in any of the methods described herein. In accordance with some embodiments, an electronic device includes: a touch-sensitive surface, one or more sensors to detect intensity of contacts with the touch-sensitive surface, optionally a display, and means for performing or causing performance of the operations of any of the methods described herein. In accordance with some embodiments, an information processing apparatus, for use in an electronic device with a touch-sensitive surface, one or more sensors to detect intensity of contacts with the touch-sensitive surface, and optionally a display includes means for performing or causing performance of the operations of any of the methods described herein. 
     In accordance with some embodiments, at least one of the aforementioned input devices has a touch-sensitive surface and one or more sensors to detect intensity of contacts with the touch-sensitive surface. Furthermore, in some embodiments, any of the aforementioned methods includes displaying, on the display, a user interface for the electronic device and detecting an input (or sequence of inputs) on the touch-sensitive surface of one of the input devices. Optionally, any of the aforementioned methods includes detecting changes in characteristics of a respective contact that is continuously detected on the touch-sensitive surface. 
     Thus, electronic devices with displays, one or more input devices that are configured to generate tactile outputs in response to inputs (e.g., including one or more input devices having touch-sensitive surfaces, and one or more sensors to detect intensity of contacts with the touch-sensitive surface) are provided with faster, more efficient methods and interfaces for performing an operation in accordance with a selected mode of operation, thereby increasing the effectiveness, efficiency, and user satisfaction with such devices. Such methods and interfaces may complement or replace conventional methods for performing an operation in accordance with a selected mode of operation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the various described embodiments, reference should be made to the Description of Embodiments below, in conjunction with the following drawings in which like reference numerals refer to corresponding parts throughout the figures. 
         FIG.  1 A  is a block diagram illustrating a portable multifunction device with a touch-sensitive display in accordance with some embodiments. 
         FIG.  1 B  is a block diagram illustrating exemplary components for event handling in accordance with some embodiments. 
         FIG.  2    illustrates a portable multifunction device having a touch screen in accordance with some embodiments. 
         FIG.  3 A  is a block diagram of an exemplary multifunction device with a display and a touch-sensitive surface in accordance with some embodiments. 
         FIG.  3 B  is a block diagram of an exemplary multifunction device with a display and a touch-sensitive surface in accordance with some embodiments. 
         FIG.  3 C  is a perspective view of an exemplary multifunction device with a touch-sensitive surface in accordance with some embodiments. 
         FIG.  3 D  is a perspective view of an input device incorporating a touch-sensitive surface separate from a multifunction device in accordance with some embodiments. 
         FIG.  3 E  is a block diagram of an exemplary multifunction device that includes a trackpad in accordance with some embodiments. 
         FIG.  3 F  is a simplified block diagram illustrating architecture of an exemplary multifunction device in accordance with some embodiments. 
         FIG.  3 G  is a block diagram illustrating data structures used by an exemplary multifunction device in accordance with some embodiments. 
         FIG.  4 A  illustrates an exemplary user interface for a menu of applications on a portable multifunction device in accordance with some embodiments. 
         FIG.  4 B  illustrates an exemplary user interface for a multifunction device with a touch-sensitive surface that is separate from the display in accordance with some embodiments. 
         FIGS.  4 C- 4 E  illustrate exemplary dynamic intensity thresholds in accordance with some embodiments. 
         FIGS.  5 A- 5 TT  illustrate exemplary user interfaces for processing touch inputs in accordance with some embodiments. 
         FIGS.  6 A- 6 C  are flow diagrams illustrating a method of processing a touch input based on an intensity stage of the touch input in accordance with some embodiments. 
         FIG.  6 D  is a flow diagram illustrating a method of processing touch information that includes an intensity stage of a touch input in accordance with some embodiments. 
         FIGS.  7 A- 7 C  are flow diagrams illustrating a method of processing touch inputs based on intensity model identifiers in accordance with some embodiments. 
         FIG.  7 D  is a flow diagram illustrating a method of processing touch information based on an intensity model identifier in accordance with some embodiments. 
         FIGS.  8 A- 8 C  are flow diagrams illustrating a method of processing touch inputs in different regions based on distinct intensity models in accordance with some embodiments. 
         FIGS.  9 A- 9 D  are flow diagrams illustrating a method of processing a touch input based on a location-related intensity model in accordance with some embodiments. 
         FIGS.  10 A- 10 D  are flow diagrams illustrating a method of processing a touch input based on latching of the touch input in accordance with some embodiments. 
         FIGS.  11 A- 11 C  are flow diagrams illustrating a method of routing a tactile output to an input device of a plurality of input devices in accordance with some embodiments. 
         FIGS.  12 A- 12 C  are flow diagrams illustrating a method of conditionally canceling or forgoing generation of a tactile output at a respective input device in accordance with some embodiments. 
         FIGS.  13 - 19    are functional block diagrams of an electronic device in accordance with some embodiments. 
         FIG.  20 A  illustrates stage zones for an exemplary gesture in accordance with some embodiments. 
         FIGS.  20 B- 20 E  illustrate exemplary intensity models in accordance with some embodiments. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Many electronic devices have user interfaces in which multiple operations are, optionally, performed in response to gestures performed using one or more input devices. In many contexts, in addition to providing the user with visual feedback on a display, to let the user know how the electronic device has responded to those gestures, it would be beneficial to provide a tactile output or tactile feedback. For example, such tactile feedback could inform the user as to when a gesture has meet predefined criteria for performing a particular operation, and/or could inform the user as to when a gesture has violated predefined criteria (e.g., for performing a particular operation or more generally for using a particular application or manipulating a user interface). The embodiments described below improve on methods for provide tactile feedback in response to an input received detected by a respective input device. For example, some embodiments described below, have one or more components, separate from an application that responds to information describing an input, for processing and routing inputs to the application, for receiving a reaction to the input from the application that indicates that a tactile output is to be generated in response to the input, and for then determining how to implement or otherwise handle the reaction received from the application. 
     In accordance with some embodiments, in response to detecting a touch input, the electronic device processes a touch input based on an intensity stage of the touch input. More specifically, the device determines the intensity stage of the touch input (e.g., at a contact intensity module) so that a software application that is separate from the contact intensity module does not need to determine the intensity stage of the touch input on its own. 
     In accordance with some embodiments, in response to detecting a touch input, the electronic device determines a touch characterization parameter for the touch input (e.g., at a contact intensity module) and sends the touch characterization parameter to a software application that is separate from the contact intensity module so that the software application does not need to directly process raw data for the touch input. More specifically, the electronic device uses an intensity model to determine the touch characterization parameter. 
     In accordance with some embodiments in which intensity models are mapped to different regions of a touch-sensitive surface, in response to a touch input, the electronic device uses an intensity model that corresponds to a location of the touch input to determine a touch characterization parameter. More specifically, different intensity models are used for different regions. 
     In accordance with some embodiments, in response to detecting movement of a touch input, the electronic device determines whether the touch input has latched to a particular region of the user interface. If the touch input is latched, the electronic device processes the touch input based on an intensity model associated with the latched region. If the touch input is not latched, the electronic device processes the touch input based on an intensity model associated with a current position of a touch input (or a cursor). 
     In accordance with some embodiments in which the electronic device is in communication with a plurality of input devices, including a first input device that is configured to generate tactile outputs in response to inputs and a second input device that is configured to generate tactile outputs, in response to receiving the reaction to the input from the application, the device causes the generation of a respective tactile output at the same input device as the input device from which an input was received that triggered the reaction. More specifically, in accordance with a determination that the reaction was triggered by the first input device, the respective tactile output is generated at the first input device based on the reaction to the input from the application, and in accordance with a determination that the reaction was triggered by the second input device, the respective tactile output is generated at the second input device based on the reaction to the input from the application. 
     In accordance with some embodiments in which the electronic device is in communication with one or more input devices that are configured to generate tactile outputs in response to inputs, in response to receiving the reaction to the input from the application, the device performs a set of operations. The set of operations include operations that conditionally cancel or forgo generation of a tactile output corresponding to the reaction from the application in accordance with a determination that tactile output criteria have not been met. The tactile output criteria include a criterion that is met when an input time is less than a predetermined amount of time before the output time. 
     Below,  FIGS.  1 A- 1 B,  2 , and  3 A- 3 G  illustrate exemplary devices.  FIGS.  4 A- 4 B and  5 A- 5 TT  illustrate exemplary user interfaces for processing touch inputs.  FIGS.  6 A- 6 C  illustrate a flow diagram of a method of processing a touch input based an intensity stage of the touch input in accordance with some embodiments.  FIG.  6 D  is a flow diagram illustrating a method of processing touch information that includes an intensity stage of a touch input in accordance with some embodiments.  FIGS.  7 A- 7 C  illustrate a flow diagram of a method of processing touch inputs based on intensity model identifiers in accordance with some embodiments.  FIG.  7 D  is a flow diagram illustrating a method of processing touch information based on an intensity model identifier in accordance with some embodiments.  FIGS.  8 A- 8 C  illustrate a flow diagram of a method of processing touch inputs in different regions based on distinct intensity models in accordance with some embodiments.  FIGS.  9 A- 9 D  illustrate a flow diagram of a method of processing a touch input based on an intensity model associated with a location of the touch input in accordance with some embodiments.  FIGS.  10 A- 10 D  illustrate a flow diagram of a method of processing a touch input based on whether the touch input has latched on to a particular region in accordance with some embodiments.  FIGS.  11 A- 11 C  are flow diagrams illustrating a method of routing a tactile output to an input device of a plurality of input devices in accordance with some embodiments.  FIGS.  12 A- 12 C  are flow diagrams illustrating a method of conditionally canceling or forgoing generation of a tactile output at a respective input device in accordance with some embodiments. The user interfaces in  FIGS.  5 A- 5 TT  are used to illustrate the processes in  FIGS.  6 A- 6 D,  7 A- 7 D,  8 A- 8 C,  9 A- 9 D,  10 A- 10 D,  11 A- 11 C, and  12 A- 12 C . 
     Exemplary Devices 
     Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the various described embodiments. However, it will be apparent to one of ordinary skill in the art that the various described embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, circuits, and networks have not been described in detail so as not to unnecessarily obscure aspects of the embodiments. 
     It will also be understood that, although the terms first, second, etc. are, in some instances, used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first contact could be termed a second contact, and, similarly, a second contact could be termed a first contact, without departing from the scope of the various described embodiments. The first contact and the second contact are both contacts, but they are not the same contact, unless the context clearly indicates otherwise. 
     The terminology used in the description of the various described embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various described embodiments and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     As used herein, the term “if” is, optionally, construed to mean “when” or “upon” or “in response to determining” or “in response to detecting,” depending on the context. Similarly, the phrase “if it is determined” or “if [a stated condition or event] is detected” is, optionally, construed to mean “upon determining” or “in response to determining” or “upon detecting [the stated condition or event]” or “in response to detecting [the stated condition or event],” depending on the context. 
     Embodiments of electronic devices, user interfaces for such devices, and associated processes for using such devices are described. In some embodiments, the device is a portable communications device, such as a mobile telephone, that also contains other functions, such as PDA and/or music player functions. Exemplary embodiments of portable multifunction devices include, without limitation, the iPhone®, iPod Touch®, and iPad® devices from Apple Inc. of Cupertino, Calif. Other portable electronic devices, such as laptops or tablet computers with touch-sensitive surfaces (e.g., touch-screen displays and/or touchpads), are, optionally, used. It should also be understood that, in some embodiments, the device is not a portable communications device, but is a desktop computer with a touch-sensitive surface (e.g., a touch-screen display and/or a touchpad). 
     In the discussion that follows, an electronic device that includes a display and a touch-sensitive surface is described. It should be understood, however, that the electronic device optionally includes one or more other physical user-interface devices, such as a physical keyboard, a mouse and/or a joystick. 
     The device typically supports a variety of applications, such as one or more of the following: a note taking application, a drawing application, a presentation application, a word processing application, a website creation application, a disk authoring application, a spreadsheet application, a gaming application, a telephone application, a video conferencing application, an e-mail application, an instant messaging application, a workout support application, a photo management application, a digital camera application, a digital video camera application, a web browsing application, a digital music player application, and/or a digital video player application. 
     The various applications that are executed on the device optionally use at least one common physical user-interface device, such as the touch-sensitive surface. One or more functions of the touch-sensitive surface as well as corresponding information displayed on the device are, optionally, adjusted and/or varied from one application to the next and/or within a respective application. In this way, a common physical architecture (such as the touch-sensitive surface) of the device optionally supports the variety of applications with user interfaces that are intuitive and transparent to the user. 
     Attention is now directed toward embodiments of portable devices with touch-sensitive displays.  FIG.  1 A  is a block diagram illustrating portable multifunction device  100  with touch-sensitive display system  112  in accordance with some embodiments. Touch-sensitive display system  112  is sometimes called a “touch screen” for convenience, and is sometimes simply called a touch-sensitive display. Device  100  includes memory  102  (which optionally includes one or more computer readable storage mediums), memory controller  122 , one or more processing units (CPUs)  120 , peripherals interface  118 , RF circuitry  108 , audio circuitry  110 , speaker  111 , microphone  113 , input/output (I/O) subsystem  106 , other input or control devices  116 , and external port  124 . Device  100  optionally includes one or more optical sensors  164 . Device  100  optionally includes one or more intensity sensors  165  for detecting intensity of contacts on device  100  (e.g., a touch-sensitive surface such as touch-sensitive display system  112  of device  100 ). Device  100  optionally includes one or more tactile output generators  167  for generating tactile outputs on device  100  (e.g., generating tactile outputs on a touch-sensitive surface such as touch-sensitive display system  112  of device  100  or touchpad  355  of device  300 ). These components optionally communicate over one or more communication buses or signal lines  103 . 
     As used in the specification and claims, the term “tactile output” refers to physical displacement of a device relative to a previous position of the device, physical displacement of a component (e.g., a touch-sensitive surface) of a device relative to another component (e.g., housing) of the device, or displacement of the component relative to a center of mass of the device that will be detected by a user with the user&#39;s sense of touch. For example, in situations where the device or the component of the device is in contact with a surface of a user that is sensitive to touch (e.g., a finger, palm, or other part of a user&#39;s hand), the tactile output generated by the physical displacement will be interpreted by the user as a tactile sensation corresponding to a perceived change in physical characteristics of the device or the component of the device. For example, movement of a touch-sensitive surface (e.g., in a touch-sensitive display or trackpad) is, optionally, interpreted by the user as a “down click” or “up click” of a physical actuator button. In some cases, a user will feel a tactile sensation such as an “down click” or “up click” even when there is no movement of a physical actuator button associated with the touch-sensitive surface that is physically pressed (e.g., displaced) by the user&#39;s movements. As another example, movement of the touch-sensitive surface is, optionally, interpreted or sensed by the user as “roughness” of the touch-sensitive surface, even when there is no change in smoothness of the touch-sensitive surface. While such interpretations of touch by a user will be subject to the individualized sensory perceptions of the user, there are many sensory perceptions of touch that are common to a large majority of users. Thus, when a tactile output is described as corresponding to a particular sensory perception of a user (e.g., an “up click,” a “down click,” “roughness”), unless otherwise stated, the generated tactile output corresponds to physical displacement of the device or a component thereof that will generate the described sensory perception for a typical (or average) user. 
     It should be appreciated that device  100  is only one example of a portable multifunction device, and that device  100  optionally has more or fewer components than shown, optionally combines two or more components, or optionally has a different configuration or arrangement of the components. The various components shown in  FIG.  1 A  are implemented in hardware, software, firmware, or a combination thereof, including one or more signal processing and/or application specific integrated circuits. 
     Memory  102  optionally includes high-speed random access memory and optionally also includes non-volatile memory, such as one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state memory devices. Access to memory  102  by other components of device  100 , such as CPU(s)  120  and the peripherals interface  118 , is, optionally, controlled by memory controller  122 . 
     Peripherals interface  118  can be used to couple input and output peripherals of the device to CPU(s)  120  and memory  102 . The one or more processors  120  run or execute various software programs and/or sets of instructions stored in memory  102  to perform various functions for device  100  and to process data. 
     In some embodiments, peripherals interface  118 , CPU(s)  120 , and memory controller  122  are, optionally, implemented on a single chip, such as chip  104 . In some other embodiments, they are, optionally, implemented on separate chips. 
     RF (radio frequency) circuitry  108  receives and sends RF signals, also called electromagnetic signals. RF circuitry  108  converts electrical signals to/from electromagnetic signals and communicates with communications networks and other communications devices via the electromagnetic signals. RF circuitry  108  optionally includes well-known circuitry for performing these functions, including but not limited to an antenna system, an RF transceiver, one or more amplifiers, a tuner, one or more oscillators, a digital signal processor, a CODEC chipset, a subscriber identity module (SIM) card, memory, and so forth. RF circuitry  108  optionally communicates with networks, such as the Internet, also referred to as the World Wide Web (WWW), an intranet and/or a wireless network, such as a cellular telephone network, a wireless local area network (LAN) and/or a metropolitan area network (MAN), and other devices by wireless communication. The wireless communication optionally uses any of a plurality of communications standards, protocols and technologies, including but not limited to Global System for Mobile Communications (GSM), Enhanced Data GSM Environment (EDGE), high-speed downlink packet access (HSDPA), high-speed uplink packet access (HSDPA), Evolution, Data-Only (EV-DO), HSPA, HSPA+, Dual-Cell HSPA (DC-HSPDA), long term evolution (LTE), near field communication (NFC), wideband code division multiple access (W-CDMA), code division multiple access (CDMA), time division multiple access (TDMA), Bluetooth, Wireless Fidelity (Wi-Fi) (e.g., IEEE 802.11a, IEEE 802.11ac, IEEE 802.11ax, IEEE 802.11b, IEEE 802.11g and/or IEEE 802.11n), voice over Internet Protocol (VoIP), Wi-MAX, a protocol for e-mail (e.g., Internet message access protocol (IMAP) and/or post office protocol (POP)), instant messaging (e.g., extensible messaging and presence protocol (XMPP), Session Initiation Protocol for Instant Messaging and Presence Leveraging Extensions (SIMPLE), Instant Messaging and Presence Service (IMPS)), and/or Short Message Service (SMS), or any other suitable communication protocol, including communication protocols not yet developed as of the filing date of this document. 
     Audio circuitry  110 , speaker  111 , and microphone  113  provide an audio interface between a user and device  100 . Audio circuitry  110  receives audio data from peripherals interface  118 , converts the audio data to an electrical signal, and transmits the electrical signal to speaker  111 . Speaker  111  converts the electrical signal to human-audible sound waves. Audio circuitry  110  also receives electrical signals converted by microphone  113  from sound waves. Audio circuitry  110  converts the electrical signal to audio data and transmits the audio data to peripherals interface  118  for processing. Audio data is, optionally, retrieved from and/or transmitted to memory  102  and/or RF circuitry  108  by peripherals interface  118 . In some embodiments, audio circuitry  110  also includes a headset jack (e.g.,  212 ,  FIG.  2   ). The headset jack provides an interface between audio circuitry  110  and removable audio input/output peripherals, such as output-only headphones or a headset with both output (e.g., a headphone for one or both ears) and input (e.g., a microphone). 
     I/O subsystem  106  couples input/output peripherals on device  100 , such as touch-sensitive display system  112  and other input or control devices  116 , with peripherals interface  118 . I/O subsystem  106  optionally includes display controller  156 , optical sensor controller  158 , intensity sensor controller  159 , haptic feedback controller  161 , and one or more input controllers  160  for other input or control devices. The one or more input controllers  160  receive/send electrical signals from/to other input or control devices  116 . The other input or control devices  116  optionally include physical buttons (e.g., push buttons, rocker buttons, etc.), dials, slider switches, joysticks, click wheels, and so forth. In some alternate embodiments, input controller(s)  160  are, optionally, coupled with any (or none) of the following: a keyboard, infrared port, USB port, stylus, and/or a pointer device such as a mouse. The one or more buttons (e.g.,  208 ,  FIG.  2   ) optionally include an up/down button for volume control of speaker  111  and/or microphone  113 . The one or more buttons optionally include a push button (e.g.,  206 ,  FIG.  2   ). 
     Touch-sensitive display system  112  provides an input interface and an output interface between the device and a user. Display controller  156  receives and/or sends electrical signals from/to touch-sensitive display system  112 . Touch-sensitive display system  112  displays visual output to the user. The visual output optionally includes graphics, text, icons, video, and any combination thereof (collectively termed “graphics”). In some embodiments, some or all of the visual output corresponds to user-interface objects. 
     Touch-sensitive display system  112  has a touch-sensitive surface, sensor or set of sensors, that accepts input from the user based on haptic and/or tactile contact. Touch-sensitive display system  112  and display controller  156  (along with any associated modules and/or sets of instructions in memory  102 ) detect contact (and any movement or breaking of the contact) on touch-sensitive display system  112  and converts the detected contact into interaction with user-interface objects (e.g., one or more soft keys, icons, web pages or images) that are displayed on touch-sensitive display system  112 . In some exemplary embodiments, a point of contact between touch-sensitive display system  112  and the user corresponds to a finger of the user or a stylus. 
     Touch-sensitive display system  112  optionally uses LCD (liquid crystal display) technology, LPD (light emitting polymer display) technology, or LED (light emitting diode) technology, although other display technologies are used in other embodiments. Touch-sensitive display system  112  and display controller  156  optionally detect contact and any movement or breaking thereof using any of a plurality of touch sensing technologies now known or later developed, including but not limited to capacitive, resistive, infrared, and surface acoustic wave technologies, as well as other proximity sensor arrays or other elements for determining one or more points of contact with touch-sensitive display system  112 . In some exemplary embodiments, projected mutual capacitance sensing technology is used, such as that found in the iPhone®, iPod Touch®, and iPad® from Apple Inc. of Cupertino, Calif. 
     Touch-sensitive display system  112  optionally has a video resolution in excess of 100 dpi. In some embodiments, the touch screen video resolution is in excess of 400 dpi (e.g., 500 dpi, 800 dpi, or greater). The user optionally makes contact with touch-sensitive display system  112  using any suitable object or appendage, such as a stylus, a finger, and so forth. In some embodiments, the user interface is designed to work with finger-based contacts and gestures, which can be less precise than stylus-based input due to the larger area of contact of a finger on the touch screen. In some embodiments, the device translates the rough finger-based input into a precise pointer/cursor position or command for performing the actions desired by the user. 
     In some embodiments, in addition to the touch screen, device  100  optionally includes a touchpad (not shown) for activating or deactivating particular functions. In some embodiments, the touchpad is a touch-sensitive area of the device that, unlike the touch screen, does not display visual output. The touchpad is, optionally, a touch-sensitive surface that is separate from touch-sensitive display system  112  or an extension of the touch-sensitive surface formed by the touch screen. 
     Device  100  also includes power system  162  for powering the various components. Power system  162  optionally includes a power management system, one or more power sources (e.g., battery, alternating current (AC)), a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator (e.g., a light-emitting diode (LED)) and any other components associated with the generation, management and distribution of power in portable devices. 
     Device  100  optionally also includes one or more optical sensors  164 .  FIG.  1 A  shows an optical sensor coupled with optical sensor controller  158  in I/O subsystem  106 . Optical sensor(s)  164  optionally include charge-coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) phototransistors. Optical sensor(s)  164  receive light from the environment, projected through one or more lens, and converts the light to data representing an image. In conjunction with imaging module  143  (also called a camera module), optical sensor(s)  164  optionally capture still images and/or video. In some embodiments, an optical sensor is located on the back of device  100 , opposite touch-sensitive display system  112  on the front of the device, so that the touch screen is enabled for use as a viewfinder for still and/or video image acquisition. In some embodiments, another optical sensor is located on the front of the device so that the user&#39;s image is obtained (e.g., for selfies, for videoconferencing while the user views the other video conference participants on the touch screen, etc.). 
     Device  100  optionally also includes one or more contact intensity sensors  165 .  FIG.  1 A  shows a contact intensity sensor coupled with intensity sensor controller  159  in I/O subsystem  106 . Contact intensity sensor(s)  165  optionally include one or more piezoresistive strain gauges, capacitive force sensors, electric force sensors, piezoelectric force sensors, optical force sensors, capacitive touch-sensitive surfaces, or other intensity sensors (e.g., sensors used to measure the force (or pressure) of a contact on a touch-sensitive surface). Contact intensity sensor(s)  165  receive contact intensity information (e.g., pressure information or a proxy for pressure information) from the environment. In some embodiments, at least one contact intensity sensor is collocated with, or proximate to, a touch-sensitive surface (e.g., touch-sensitive display system  112 ). In some embodiments, at least one contact intensity sensor is located on the back of device  100 , opposite touch-screen display system  112  which is located on the front of device  100 . 
     Device  100  optionally also includes one or more proximity sensors  166 .  FIG.  1 A  shows proximity sensor  166  coupled with peripherals interface  118 . Alternately, proximity sensor  166  is coupled with input controller  160  in I/O subsystem  106 . In some embodiments, the proximity sensor turns off and disables touch-sensitive display system  112  when the multifunction device is placed near the user&#39;s ear (e.g., when the user is making a phone call). 
     Device  100  optionally also includes one or more tactile output generators  167 .  FIG.  1 A  shows a tactile output generator coupled with haptic feedback controller  161  in I/O subsystem  106 . Tactile output generator(s)  167  optionally include one or more electroacoustic devices such as speakers or other audio components and/or electromechanical devices that convert energy into linear motion such as a motor, solenoid, electroactive polymer, piezoelectric actuator, electrostatic actuator, or other tactile output generating component (e.g., a component that converts electrical signals into tactile outputs on the device). In some embodiments, tactile output generator(s)  167  receive tactile feedback generation instructions from haptic feedback module  133  and generates tactile outputs on device  100  that are capable of being sensed by a user of device  100 . In some embodiments, at least one tactile output generator is collocated with, or proximate to, a touch-sensitive surface (e.g., touch-sensitive display system  112 ) and, optionally, generates a tactile output by moving the touch-sensitive surface vertically (e.g., in/out of a surface of device  100 ) or laterally (e.g., back and forth in the same plane as a surface of device  100 ). In some embodiments, at least one tactile output generator sensor is located on the back of device  100 , opposite touch-sensitive display system  112 , which is located on the front of device  100 . 
     Device  100  optionally also includes one or more accelerometers  168 .  FIG.  1 A  shows accelerometer  168  coupled with peripherals interface  118 . Alternately, accelerometer  168  is, optionally, coupled with an input controller  160  in I/O subsystem  106 . In some embodiments, information is displayed on the touch-screen display in a portrait view or a landscape view based on an analysis of data received from the one or more accelerometers. Device  100  optionally includes, in addition to accelerometer(s)  168 , a magnetometer (not shown) and a GPS (or GLONASS or other global navigation system) receiver (not shown) for obtaining information concerning the location and orientation (e.g., portrait or landscape) of device  100 . 
     In some embodiments, the software components stored in memory  102  include operating system  126 , communication module (or set of instructions)  128 , contact/motion module (or set of instructions)  130 , graphics module (or set of instructions)  132 , haptic feedback module (or set of instructions)  133 , text input module (or set of instructions)  134 , Global Positioning System (GPS) module (or set of instructions)  135 , and applications (or sets of instructions)  136 . Furthermore, in some embodiments, memory  102  stores device/global internal state  157 , as shown in  FIGS.  1 A and  3 A- 3 B . Device/global internal state  157  includes one or more of: active application state, indicating which applications, if any, are currently active; display state, indicating what applications, views or other information occupy various regions of touch-sensitive display system  112 ; sensor state, including information obtained from the device&#39;s various sensors and other input or control devices  116 ; and location and/or positional information concerning the device&#39;s location and/or attitude. 
     Operating system  126  (e.g., iOS, Darwin, RTXC, LINUX, UNIX, OS X, WINDOWS, or an embedded operating system such as VxWorks) includes various software components and/or drivers for controlling and managing general system tasks (e.g., memory management, storage device control, power management, etc.) and facilitates communication between various hardware and software components. 
     Communication module  128  facilitates communication with other devices over one or more external ports  124  and also includes various software components for handling data received by RF circuitry  108  and/or external port  124 . External port  124  (e.g., Universal Serial Bus (USB), FIREWIRE, etc.) is adapted for coupling directly to other devices or indirectly over a network (e.g., the Internet, wireless LAN, etc.). In some embodiments, the external port is a multi-pin (e.g., 30-pin) connector that is the same as, or similar to and/or compatible with the 30-pin connector used in some iPhone®, iPod Touch®, and iPad® devices from Apple Inc. of Cupertino, Calif. In some embodiments, the external port is a Lightning connector that is the same as, or similar to and/or compatible with the Lightning connector used in some iPhone®, iPod Touch®, and iPad® devices from Apple Inc. of Cupertino, Calif. 
     Contact/motion module  130  optionally detects contact with touch-sensitive display system  112  (in conjunction with display controller  156 ) and other touch-sensitive devices (e.g., a touchpad or physical click wheel). Contact/motion module  130  includes various software components for performing various operations related to detection of contact (e.g., by a finger or by a stylus), such as determining if contact has occurred (e.g., detecting a finger-down event), determining an intensity of the contact (e.g., the force or pressure of the contact or a substitute for the force or pressure of the contact), determining if there is movement of the contact and tracking the movement across the touch-sensitive surface (e.g., detecting one or more finger-dragging events), and determining if the contact has ceased (e.g., detecting a finger-up event or a break in contact). Contact/motion module  130  receives contact data from the touch-sensitive surface. Determining movement of the point of contact, which is represented by a series of contact data, optionally includes determining speed (magnitude), velocity (magnitude and direction), and/or an acceleration (a change in magnitude and/or direction) of the point of contact. These operations are, optionally, applied to single contacts (e.g., one finger contacts or stylus contacts) or to multiple simultaneous contacts (e.g., “multitouch”/multiple finger contacts). In some embodiments, contact/motion module  130  and display controller  156  detect contact on a touchpad. 
     Contact/motion module  130  optionally detects a gesture input by a user. Different gestures on the touch-sensitive surface have different contact patterns (e.g., different motions, timings, and/or intensities of detected contacts). Thus, a gesture is, optionally, detected by detecting a particular contact pattern. For example, detecting a finger tap gesture includes detecting a finger-down event followed by detecting a finger-up (lift off) event at the same position (or substantially the same position) as the finger-down event (e.g., at the position of an icon). As another example, detecting a finger swipe gesture on the touch-sensitive surface includes detecting a finger-down event followed by detecting one or more finger-dragging events, and subsequently followed by detecting a finger-up (lift off) event. Similarly, tap, swipe, drag, and other gestures are optionally detected for a stylus by detecting a particular contact pattern for the stylus. 
     Graphics module  132  includes various known software components for rendering and displaying graphics on touch-sensitive display system  112  or other display, including components for changing the visual impact (e.g., brightness, transparency, saturation, contrast or other visual property) of graphics that are displayed. As used herein, the term “graphics” includes any object that can be displayed to a user, including without limitation text, web pages, icons (such as user-interface objects including soft keys), digital images, videos, animations and the like. 
     In some embodiments, graphics module  132  stores data representing graphics to be used. Each graphic is, optionally, assigned a corresponding code. Graphics module  132  receives, from applications etc., one or more codes specifying graphics to be displayed along with, if necessary, coordinate data and other graphic property data, and then generates screen image data to output to display controller  156 . 
     Haptic feedback module  133  includes various software components for generating instructions (e.g., used by haptic feedback controller  161 ) to produce tactile outputs using tactile output generator(s)  167  at one or more locations on device  100  in response to user interactions with device  100 . 
     Text input module  134 , which is, optionally, a component of graphics module  132 , provides soft keyboards for entering text in various applications (e.g., contacts  137 , e-mail  140 , IM  141 , browser  147 , and any other application that needs text input). 
     GPS module  135  determines the location of the device and provides this information for use in various applications (e.g., to telephone  138  for use in location-based dialing, to camera  143  as picture/video metadata, and to applications that provide location-based services such as weather widgets, local yellow page widgets, and map/navigation widgets). 
     Applications  136  optionally include the following modules (or sets of instructions), or a subset or superset thereof:
         contacts module  137  (sometimes called an address book or contact list);   telephone module  138 ;   video conferencing module  139 ;   e-mail client module  140 ;   instant messaging (IM) module  141 ;   workout support module  142 ;   camera module  143  for still and/or video images;   image management module  144 ;   browser module  147 ;   calendar module  148 ;   widget modules  149 , which optionally include one or more of: weather widget  149 - 1 , stocks widget  149 - 2 , calculator widget  149 - 3 , alarm clock widget  149 - 4 , dictionary widget  149 - 5 , and other widgets obtained by the user, as well as user-created widgets  149 - 6 ;   widget creator module  150  for making user-created widgets  149 - 6 ;   search module  151 ;   video and music player module  152 , which is, optionally, made up of a video player module and a music player module;   notes module  153 ;   map module  154 ; and/or   online video module  155 .       

     Examples of other applications  136  that are, optionally, stored in memory  102  include other word processing applications, other image editing applications, drawing applications, presentation applications, JAVA-enabled applications, encryption, digital rights management, voice recognition, and voice replication. 
     In conjunction with touch-sensitive display system  112 , display controller  156 , contact module  130 , graphics module  132 , and text input module  134 , contacts module  137  includes executable instructions to manage an address book or contact list (e.g., stored in application internal state  192  of contacts module  137  in memory  102  or memory  370 ), including: adding name(s) to the address book; deleting name(s) from the address book; associating telephone number(s), e-mail address(es), physical address(es) or other information with a name; associating an image with a name; categorizing and sorting names; providing telephone numbers and/or e-mail addresses to initiate and/or facilitate communications by telephone  138 , video conference  139 , e-mail  140 , or IM  141 ; and so forth. 
     In conjunction with RF circuitry  108 , audio circuitry  110 , speaker  111 , microphone  113 , touch-sensitive display system  112 , display controller  156 , contact module  130 , graphics module  132 , and text input module  134 , telephone module  138  includes executable instructions to enter a sequence of characters corresponding to a telephone number, access one or more telephone numbers in address book  137 , modify a telephone number that has been entered, dial a respective telephone number, conduct a conversation and disconnect or hang up when the conversation is completed. As noted above, the wireless communication optionally uses any of a plurality of communications standards, protocols and technologies. 
     In conjunction with RF circuitry  108 , audio circuitry  110 , speaker  111 , microphone  113 , touch-sensitive display system  112 , display controller  156 , optical sensor(s)  164 , optical sensor controller  158 , contact module  130 , graphics module  132 , text input module  134 , contact list  137 , and telephone module  138 , videoconferencing module  139  includes executable instructions to initiate, conduct, and terminate a video conference between a user and one or more other participants in accordance with user instructions. 
     In conjunction with RF circuitry  108 , touch-sensitive display system  112 , display controller  156 , contact module  130 , graphics module  132 , and text input module  134 , e-mail client module  140  includes executable instructions to create, send, receive, and manage e-mail in response to user instructions. In conjunction with image management module  144 , e-mail client module  140  makes it very easy to create and send e-mails with still or video images taken with camera module  143 . 
     In conjunction with RF circuitry  108 , touch-sensitive display system  112 , display controller  156 , contact module  130 , graphics module  132 , and text input module  134 , the instant messaging module  141  includes executable instructions to enter a sequence of characters corresponding to an instant message, to modify previously entered characters, to transmit a respective instant message (for example, using a Short Message Service (SMS) or Multimedia Message Service (MMS) protocol for telephony-based instant messages or using XMPP, SIMPLE, Apple Push Notification Service (APNs) or IMPS for Internet-based instant messages), to receive instant messages and to view received instant messages. In some embodiments, transmitted and/or received instant messages optionally include graphics, photos, audio files, video files and/or other attachments as are supported in a MMS and/or an Enhanced Messaging Service (EMS). As used herein, “instant messaging” refers to both telephony-based messages (e.g., messages sent using SMS or MMS) and Internet-based messages (e.g., messages sent using XMPP, SIMPLE, APNs, or IMPS). 
     In conjunction with RF circuitry  108 , touch-sensitive display system  112 , display controller  156 , contact module  130 , graphics module  132 , text input module  134 , GPS module  135 , map module  154 , and music player module  146 , workout support module  142  includes executable instructions to create workouts (e.g., with time, distance, and/or calorie burning goals); communicate with workout sensors (in sports devices and smart watches); receive workout sensor data; calibrate sensors used to monitor a workout; select and play music for a workout; and display, store and transmit workout data. 
     In conjunction with touch-sensitive display system  112 , display controller  156 , optical sensor(s)  164 , optical sensor controller  158 , contact module  130 , graphics module  132 , and image management module  144 , camera module  143  includes executable instructions to capture still images or video (including a video stream) and store them into memory  102 , modify characteristics of a still image or video, and/or delete a still image or video from memory  102 . 
     In conjunction with touch-sensitive display system  112 , display controller  156 , contact module  130 , graphics module  132 , text input module  134 , and camera module  143 , image management module  144  includes executable instructions to arrange, modify (e.g., edit), or otherwise manipulate, label, delete, present (e.g., in a digital slide show or album), and store still and/or video images. 
     In conjunction with RF circuitry  108 , touch-sensitive display system  112 , display system controller  156 , contact module  130 , graphics module  132 , and text input module  134 , browser module  147  includes executable instructions to browse the Internet in accordance with user instructions, including searching, linking to, receiving, and displaying web pages or portions thereof, as well as attachments and other files linked to web pages. 
     In conjunction with RF circuitry  108 , touch-sensitive display system  112 , display system controller  156 , contact module  130 , graphics module  132 , text input module  134 , e-mail client module  140 , and browser module  147 , calendar module  148  includes executable instructions to create, display, modify, and store calendars and data associated with calendars (e.g., calendar entries, to do lists, etc.) in accordance with user instructions. 
     In conjunction with RF circuitry  108 , touch-sensitive display system  112 , display system controller  156 , contact module  130 , graphics module  132 , text input module  134 , and browser module  147 , widget modules  149  are mini-applications that are, optionally, downloaded and used by a user (e.g., weather widget  149 - 1 , stocks widget  149 - 2 , calculator widget  149 - 3 , alarm clock widget  149 - 4 , and dictionary widget  149 - 5 ) or created by the user (e.g., user-created widget  149 - 6 ). In some embodiments, a widget includes an HTML (Hypertext Markup Language) file, a CSS (Cascading Style Sheets) file, and a JavaScript file. In some embodiments, a widget includes an XML (Extensible Markup Language) file and a JavaScript file (e.g., Yahoo! Widgets). 
     In conjunction with RF circuitry  108 , touch-sensitive display system  112 , display system controller  156 , contact module  130 , graphics module  132 , text input module  134 , and browser module  147 , the widget creator module  150  includes executable instructions to create widgets (e.g., turning a user-specified portion of a web page into a widget). 
     In conjunction with touch-sensitive display system  112 , display system controller  156 , contact module  130 , graphics module  132 , and text input module  134 , search module  151  includes executable instructions to search for text, music, sound, image, video, and/or other files in memory  102  that match one or more search criteria (e.g., one or more user-specified search terms) in accordance with user instructions. 
     In conjunction with touch-sensitive display system  112 , display system controller  156 , contact module  130 , graphics module  132 , audio circuitry  110 , speaker  111 , RF circuitry  108 , and browser module  147 , video and music player module  152  includes executable instructions that allow the user to download and play back recorded music and other sound files stored in one or more file formats, such as MP3 or AAC files, and executable instructions to display, present or otherwise play back videos (e.g., on touch-sensitive display system  112 , or on an external display connected wirelessly or via external port  124 ). In some embodiments, device  100  optionally includes the functionality of an MP3 player, such as an iPod (trademark of Apple Inc.). 
     In conjunction with touch-sensitive display system  112 , display controller  156 , contact module  130 , graphics module  132 , and text input module  134 , notes module  153  includes executable instructions to create and manage notes, to do lists, and the like in accordance with user instructions. 
     In conjunction with RF circuitry  108 , touch-sensitive display system  112 , display system controller  156 , contact module  130 , graphics module  132 , text input module  134 , GPS module  135 , and browser module  147 , map module  154  includes executable instructions to receive, display, modify, and store maps and data associated with maps (e.g., driving directions; data on stores and other points of interest at or near a particular location; and other location-based data) in accordance with user instructions. 
     In conjunction with touch-sensitive display system  112 , display system controller  156 , contact module  130 , graphics module  132 , audio circuitry  110 , speaker  111 , RF circuitry  108 , text input module  134 , e-mail client module  140 , and browser module  147 , online video module  155  includes executable instructions that allow the user to access, browse, receive (e.g., by streaming and/or download), play back (e.g., on the touch screen  112 , or on an external display connected wirelessly or via external port  124 ), send an e-mail with a link to a particular online video, and otherwise manage online videos in one or more file formats, such as H.264. In some embodiments, instant messaging module  141 , rather than e-mail client module  140 , is used to send a link to a particular online video. 
     Each of the above identified modules and applications correspond to a set of executable instructions for performing one or more functions described above and the methods described in this application (e.g., the computer-implemented methods and other information processing methods described herein). These modules (i.e., sets of instructions) need not be implemented as separate software programs, procedures or modules, and thus various subsets of these modules are, optionally, combined or otherwise re-arranged in various embodiments. In some embodiments, memory  102  optionally stores a subset of the modules and data structures identified above. Furthermore, memory  102  optionally stores additional modules and data structures not described above. 
     In some embodiments, device  100  is a device where operation of a predefined set of functions on the device is performed exclusively through a touch screen and/or a touchpad. By using a touch screen and/or a touchpad as the primary input control device for operation of device  100 , the number of physical input control devices (such as push buttons, dials, and the like) on device  100  is, optionally, reduced. 
     The predefined set of functions that are performed exclusively through a touch screen and/or a touchpad optionally include navigation between user interfaces. In some embodiments, the touchpad, when touched by the user, navigates device  100  to a main, home, or root menu from any user interface that is displayed on device  100 . In such embodiments, a “menu button” is implemented using a touchpad. In some other embodiments, the menu button is a physical push button or other physical input control device instead of a touchpad. 
       FIG.  1 B  is a block diagram illustrating exemplary components for event handling in accordance with some embodiments. In some embodiments, memory  102  (in  FIG.  1 A ) or  370  ( FIG.  3 A or  3 B ) includes event sorter  170  (e.g., in operating system  126 ) and a respective application  136 - 1  (e.g., any of the aforementioned applications  136 ,  137 - 155 ,  380 - 390 ). 
     Event sorter  170  receives event information and determines the application  136 - 1  and application view  191  of application  136 - 1  to which to deliver the event information. Event sorter  170  includes event monitor  171  and event dispatcher module  174 . In some embodiments, application  136 - 1  includes application internal state  192 , which indicates the current application view(s) displayed on touch-sensitive display system  112  when the application is active or executing. In some embodiments, device/global internal state  157  is used by event sorter  170  to determine which application(s) is (are) currently active, and application internal state  192  is used by event sorter  170  to determine application views  191  to which to deliver event information. 
     In some embodiments, application internal state  192  includes additional information, such as one or more of: resume information to be used when application  136 - 1  resumes execution, user interface state information that indicates information being displayed or that is ready for display by application  136 - 1 , a state queue for enabling the user to go back to a prior state or view of application  136 - 1 , and a redo/undo queue of previous actions taken by the user. 
     Event monitor  171  receives event information from peripherals interface  118 . Event information includes information about a sub-event (e.g., a user touch on touch-sensitive display system  112 , as part of a multi-touch gesture). Peripherals interface  118  transmits information it receives from I/O subsystem  106  or a sensor, such as proximity sensor  166 , accelerometer(s)  168 , and/or microphone  113  (through audio circuitry  110 ). Information that peripherals interface  118  receives from I/O subsystem  106  includes information from touch-sensitive display system  112  or a touch-sensitive surface. 
     In some embodiments, event monitor  171  sends requests to the peripherals interface  118  at predetermined intervals. In response, peripherals interface  118  transmits event information. In other embodiments, peripheral interface  118  transmits event information only when there is a significant event (e.g., receiving an input above a predetermined noise threshold and/or for more than a predetermined duration). 
     In some embodiments, event sorter  170  also includes a hit view determination module  172  and/or an active event recognizer determination module  173 . 
     Hit view determination module  172  provides software procedures for determining where a sub-event has taken place within one or more views, when touch-sensitive display system  112  displays more than one view. Views are made up of controls and other elements that a user can see on the display. 
     Another aspect of the user interface associated with an application is a set of views, sometimes herein called application views or user interface windows, in which information is displayed and touch-based gestures occur. The application views (of a respective application) in which a touch is detected optionally correspond to programmatic levels within a programmatic or view hierarchy of the application. For example, the lowest level view in which a touch is detected is, optionally, called the hit view, and the set of events that are recognized as proper inputs are, optionally, determined based, at least in part, on the hit view of the initial touch that begins a touch-based gesture. 
     Hit view determination module  172  receives information related to sub-events of a touch-based gesture. When an application has multiple views organized in a hierarchy, hit view determination module  172  identifies a hit view as the lowest view in the hierarchy which should handle the sub-event. In most circumstances, the hit view is the lowest level view in which an initiating sub-event occurs (i.e., the first sub-event in the sequence of sub-events that form an event or potential event). Once the hit view is identified by the hit view determination module, the hit view typically receives all sub-events related to the same touch or input source for which it was identified as the hit view. 
     Active event recognizer determination module  173  determines which view or views within a view hierarchy should receive a particular sequence of sub-events. In some embodiments, active event recognizer determination module  173  determines that only the hit view should receive a particular sequence of sub-events. In other embodiments, active event recognizer determination module  173  determines that all views that include the physical location of a sub-event are actively involved views, and therefore determines that all actively involved views should receive a particular sequence of sub-events. In other embodiments, even if touch sub-events were entirely confined to the area associated with one particular view, views higher in the hierarchy would still remain as actively involved views. 
     Event dispatcher module  174  dispatches the event information to an event recognizer (e.g., event recognizer  180 ). In embodiments including active event recognizer determination module  173 , event dispatcher module  174  delivers the event information to an event recognizer determined by active event recognizer determination module  173 . In some embodiments, event dispatcher module  174  stores in an event queue the event information, which is retrieved by a respective event receiver module  182 . 
     In some embodiments, operating system  126  includes event sorter  170 . Alternatively, application  136 - 1  includes event sorter  170 . In yet other embodiments, event sorter  170  is a stand-alone module, or a part of another module stored in memory  102 , such as contact/motion module  130 . 
     In some embodiments, application  136 - 1  includes a plurality of event handlers  190  and one or more application views  191 , each of which includes instructions for handling touch events that occur within a respective view of the application&#39;s user interface. Each application view  191  of the application  136 - 1  includes one or more event recognizers  180 . Typically, a respective application view  191  includes a plurality of event recognizers  180 . In other embodiments, one or more of event recognizers  180  are part of a separate module, such as a user interface kit (not shown) or a higher level object from which application  136 - 1  inherits methods and other properties. In some embodiments, a respective event handler  190  includes one or more of: data updater  176 , object updater  177 , GUI updater  178 , and/or event data  179  received from event sorter  170 . Event handler  190  optionally utilizes or calls data updater  176 , object updater  177  or GUI updater  178  to update the application internal state  192 . Alternatively or additionally, one or more of the application views  191  includes one or more respective event handlers  190 . Also, in some embodiments, one or more of data updater  176 , object updater  177 , and GUI updater  178  are included in a respective application view  191 . 
     A respective event recognizer  180  receives event information (e.g., event data  179 ) from event sorter  170 , and identifies an event from the event information. Event recognizer  180  includes event receiver  182  and event comparator  184 . In some embodiments, event recognizer  180  also includes at least a subset of: metadata  183 , and event delivery instructions  188  (which optionally include sub-event delivery instructions). 
     Event receiver  182  receives event information from event sorter  170 . The event information includes information about a sub-event, for example, a touch or a touch movement. Depending on the sub-event, the event information also includes additional information, such as location of the sub-event. When the sub-event concerns motion of a touch, the event information optionally also includes speed and direction of the sub-event. In some embodiments, events include rotation of the device from one orientation to another (e.g., from a portrait orientation to a landscape orientation, or vice versa), and the event information includes corresponding information about the current orientation (also called device attitude) of the device. 
     Event comparator  184  compares the event information to predefined event or sub-event definitions and, based on the comparison, determines an event or sub-event, or determines or updates the state of an event or sub-event. In some embodiments, event comparator  184  includes event definitions  186 . Event definitions  186  contain definitions of events (e.g., predefined sequences of sub-events), for example, event 1 ( 187 - 1 ), event 2 ( 187 - 2 ), and others. In some embodiments, sub-events in an event  187  include, for example, touch begin, touch end, touch movement, touch cancellation, and multiple touching. In one example, the definition for event 1 ( 187 - 1 ) is a double tap on a displayed object. The double tap, for example, comprises a first touch (touch begin) on the displayed object for a predetermined phase, a first lift-off (touch end) for a predetermined phase, a second touch (touch begin) on the displayed object for a predetermined phase, and a second lift-off (touch end) for a predetermined phase. In another example, the definition for event 2 ( 187 - 2 ) is a dragging on a displayed object. The dragging, for example, comprises a touch (or contact) on the displayed object for a predetermined phase, a movement of the touch across touch-sensitive display system  112 , and lift-off of the touch (touch end). In some embodiments, the event also includes information for one or more associated event handlers  190 . 
     In some embodiments, event definition  187  includes a definition of an event for a respective user-interface object. In some embodiments, event comparator  184  performs a hit test to determine which user-interface object is associated with a sub-event. For example, in an application view in which three user-interface objects are displayed on touch-sensitive display system  112 , when a touch is detected on touch-sensitive display system  112 , event comparator  184  performs a hit test to determine which of the three user-interface objects is associated with the touch (sub-event). If each displayed object is associated with a respective event handler  190 , the event comparator uses the result of the hit test to determine which event handler  190  should be activated. For example, event comparator  184  selects an event handler associated with the sub-event and the object triggering the hit test. 
     In some embodiments, the definition for a respective event  187  also includes delayed actions that delay delivery of the event information until after it has been determined whether the sequence of sub-events does or does not correspond to the event recognizer&#39;s event type. 
     When a respective event recognizer  180  determines that the series of sub-events do not match any of the events in event definitions  186 , the respective event recognizer  180  enters an event impossible, event failed, or event ended state, after which it disregards subsequent sub-events of the touch-based gesture. In this situation, other event recognizers, if any, that remain active for the hit view continue to track and process sub-events of an ongoing touch-based gesture. 
     In some embodiments, a respective event recognizer  180  includes metadata  183  with configurable properties, flags, and/or lists that indicate how the event delivery system should perform sub-event delivery to actively involved event recognizers. In some embodiments, metadata  183  includes configurable properties, flags, and/or lists that indicate how event recognizers interact, or are enabled to interact, with one another. In some embodiments, metadata  183  includes configurable properties, flags, and/or lists that indicate whether sub-events are delivered to varying levels in the view or programmatic hierarchy. 
     In some embodiments, a respective event recognizer  180  activates event handler  190  associated with an event when one or more particular sub-events of an event are recognized. In some embodiments, a respective event recognizer  180  delivers event information associated with the event to event handler  190 . Activating an event handler  190  is distinct from sending (and deferred sending) sub-events to a respective hit view. In some embodiments, event recognizer  180  throws a flag associated with the recognized event, and event handler  190  associated with the flag catches the flag and performs a predefined process. 
     In some embodiments, event delivery instructions  188  include sub-event delivery instructions that deliver event information about a sub-event without activating an event handler. Instead, the sub-event delivery instructions deliver event information to event handlers associated with the series of sub-events or to actively involved views. Event handlers associated with the series of sub-events or with actively involved views receive the event information and perform a predetermined process. 
     In some embodiments, data updater  176  creates and updates data used in application  136 - 1 . For example, data updater  176  updates the telephone number used in contacts module  137 , or stores a video file used in video player module  145 . In some embodiments, object updater  177  creates and updates objects used in application  136 - 1 . For example, object updater  177  creates a new user-interface object or updates the position of a user-interface object. GUI updater  178  updates the GUI. For example, GUI updater  178  prepares display information and sends it to graphics module  132  for display on a touch-sensitive display. 
     In some embodiments, event handler(s)  190  includes or has access to data updater  176 , object updater  177 , and GUI updater  178 . In some embodiments, data updater  176 , object updater  177 , and GUI updater  178  are included in a single module of a respective application  136 - 1  or application view  191 . In other embodiments, they are included in two or more software modules. 
     It shall be understood that the foregoing discussion regarding event handling of user touches on touch-sensitive displays also applies to other forms of user inputs to operate multifunction devices  100  with input-devices, not all of which are initiated on touch screens. For example, mouse movement and mouse button presses, optionally coordinated with single or multiple keyboard presses or holds; contact movements such as taps, drags, scrolls, etc., on touch-pads; pen stylus inputs; movement of the device; oral instructions; detected eye movements; biometric inputs; and/or any combination thereof are optionally utilized as inputs corresponding to sub-events which define an event to be recognized. 
       FIG.  2    illustrates a portable multifunction device  100  having a touch screen (e.g., touch-sensitive display system  112 ,  FIG.  1 A ) in accordance with some embodiments. The touch screen optionally displays one or more graphics within user interface (UI)  200 . In these embodiments, as well as others described below, a user is enabled to select one or more of the graphics by making a gesture on the graphics, for example, with one or more fingers  202  (not drawn to scale in the figure) or one or more styluses  203  (not drawn to scale in the figure). In some embodiments, selection of one or more graphics occurs when the user breaks contact with the one or more graphics. In some embodiments, the gesture optionally includes one or more taps, one or more swipes (from left to right, right to left, upward and/or downward) and/or a rolling of a finger (from right to left, left to right, upward and/or downward) that has made contact with device  100 . In some implementations or circumstances, inadvertent contact with a graphic does not select the graphic. For example, a swipe gesture that sweeps over an application icon optionally does not select the corresponding application when the gesture corresponding to selection is a tap. 
     Device  100  optionally also includes one or more physical buttons, such as “home” or menu button  204 . As described previously, menu button  204  is, optionally, used to navigate to any application  136  in a set of applications that are, optionally executed on device  100 . Alternatively, in some embodiments, the menu button is implemented as a soft key in a GUI displayed on the touch-screen display. 
     In some embodiments, device  100  includes the touch-screen display, menu button  204 , push button  206  for powering the device on/off and locking the device, volume adjustment button(s)  208 , Subscriber Identity Module (SIM) card slot  210 , head set jack  212 , and docking/charging external port  124 . Push button  206  is, optionally, used to turn the power on/off on the device by depressing the button and holding the button in the depressed state for a predefined time interval; to lock the device by depressing the button and releasing the button before the predefined time interval has elapsed; and/or to unlock the device or initiate an unlock process. In some embodiments, device  100  also accepts verbal input for activation or deactivation of some functions through microphone  113 . Device  100  also, optionally, includes one or more contact intensity sensors  165  for detecting intensity of contacts on touch-sensitive display system  112  and/or one or more tactile output generators  167  for generating tactile outputs for a user of device  100 . 
       FIG.  3 A  is a block diagram of an exemplary multifunction device  300  with a display  340  and a touch-sensitive surface  355  in accordance with some embodiments. Device  300  need not be portable. In some embodiments, device  300  is a laptop computer, a desktop computer, a tablet computer, a multimedia player device, a navigation device, an educational device (such as a child&#39;s learning toy), a gaming system, or a control device (e.g., a home or industrial controller). 
     Device  300  typically includes one or more processing units (also called herein CPU&#39;s and processors)  310 , one or more network or other communications interfaces  360 , memory  370 , and one or more communication buses  320  for interconnecting these components. Communication buses  320  optionally include circuitry (sometimes called a chipset) that interconnects and controls communications between system components. 
     Device  300  includes input/output (I/O) interface  330  comprising display  340 , which is a touch-screen display in some embodiments. In some embodiments, I/O interface  330  is coupled to the one or more processing units  310  and/or memory  370  through a peripherals interface (not shown in  FIG.  3 A ). I/O interface  330  also optionally includes a keyboard and/or mouse (or other pointing device)  350  and touchpad  355 , tactile output generator  357  for generating tactile outputs on device  300  (e.g., similar to tactile output generator(s)  167  described above with reference to  FIG.  1 A ), contact intensity sensors  359 , similar to contact intensity sensor(s)  165  described above with reference to  FIG.  1 A , and/or other sensors  361  (e.g., optical, acceleration, proximity, and/or touch-sensitive sensors). 
     Memory  370  includes high-speed random access memory, such as DRAM, SRAM, DDR RAM or other random access solid state memory devices; and optionally includes non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. Memory  370  optionally includes one or more storage devices remotely located from CPU(s)  310 . 
     In some embodiments, memory  370  stores programs, modules, and data structures analogous to the programs, modules, and data structures stored in memory  102  of portable multifunction device  100  ( FIG.  1 A ), or a subset thereof. Furthermore, memory  370  optionally stores additional programs, modules, and data structures not present in memory  102  of portable multifunction device  100 . For example, memory  370  of device  300  optionally stores drawing module  380 , presentation module  382 , word processing module  384 , website creation module  386 , disk authoring module  388 , and/or spreadsheet module  390 , while memory  102  of portable multifunction device  100  ( FIG.  1 A ) optionally does not store these modules. 
     In some embodiments, the operating system  126  includes one or more device modules  127  (also called device drivers). The one or more device modules  127  include software components that operate or control particular hardware devices included in or in communication with the multifunction device  300  (e.g., touchpad  355 , tactile output generators  357 , intensity sensors  359 , and other sensors  361  shown in  FIG.  3 A  and/or trackpad  332  and its components shown in  FIG.  3 B ). 
     Each of the above identified elements in  FIG.  3 A  are, optionally, stored in one or more of the previously mentioned memory devices. Each of the above identified modules corresponds to a set of instructions for performing a function described above. The above identified modules or programs (i.e., sets of instructions) need not be implemented as separate software programs, procedures or modules, and thus various subsets of these modules are, optionally, combined or otherwise re-arranged in various embodiments. In some embodiments, memory  370  optionally stores a subset of the modules and data structures identified above. Furthermore, memory  370  optionally stores additional modules and data structures not described above. 
       FIG.  3 B  is a block diagram of an exemplary multifunction device  300  with a display and a touch-sensitive surface in accordance with some embodiments.  FIG.  3 B  is similar to  FIG.  3 A  except that the multifunction device  300  in  FIG.  3 B  includes trackpad  332  that is coupled to the Peripherals Interface  118  through External Port  124  (e.g., using a USB port or any other wired communication protocols). Alternatively, the trackpad  332  may be coupled to the Peripherals Interface  118  through RF circuitry  108  (e.g., using Bluetooth or any other form of wireless communication protocols). In some embodiments, the trackpad  332  is located outside an enclosure for the device  300 . In comparison, the touchpad  355  is typically integrated with the enclosure for the device  300 . In some embodiments, the trackpad  332  is integrated with the enclosure for the device  300 . In some embodiments, the device  300  includes the trackpad  332  in addition to the touchpad  355  (and/or tactile output generator(s)  357 ). In some embodiments, the device  300  includes the trackpad  332  instead of the touchpad  355  (and/or tactile output generator(s)  357 ). 
     The trackpad  332  includes touch-sensitive surface  334 . In some embodiments, the trackpad  332  includes one or more intensity sensors  336  to detect intensity of contacts on the touch-sensitive surface  334 . In some embodiments, the trackpad  332  includes one or more tactile output generators  338 . In some embodiments, the trackpad  332  includes one or more processors  342  to process signals from the touch-sensitive surface  334  and the one or more intensity sensors  336 , if included, and control operations of the one or more tactile output generators  338 , if included. In some embodiments, the one or more processors  342  include Intensity Sensors Controller  159  and/or Haptic Feedback Controller  161  described above with respect to  FIG.  1 A . In some embodiments, the one or more processors  342  are configured to detect contact (and any movement or breaking of the contact) on the touch-sensitive surface  334  and convert the detected contact into predefined user inputs, such as predefined touch gestures, which are processed by software applications to initiate interaction with user-interface objects (e.g., one or more soft keys, icons, web pages or images) that are displayed on touch-sensitive display system  112 . In some embodiments, the touchpad  355  also includes a touch-sensitive surface and one or more processors similar to the one or more processors  342  of the trackpad  332 . 
     The trackpad  332  includes Communication Module  344  to transmit information to the one or more processing units  310  through the Peripherals Interface  118  and/or receive instructions from the one or more processing units  310  and/or the Peripherals Interface  118 . 
     In some embodiments, the trackpad  332  includes other sensors  346 , such as a proximity sensor, an accelerometer, etc. 
       FIG.  3 C  is a perspective view of an exemplary multifunction device  300  with a touch-sensitive surface in accordance with some embodiments. As shown in  FIG.  3 C , the device  300  may be a laptop computer. The device  300  includes enclosure  302 , display  340 , touchpad  355 , mouse  350 , one or more external ports  124 , and one or more input or control devices  116  (e.g., a power on/off button). The enclosure  302  forms at least a portion of an exterior of the device  300 . In some embodiments, the enclosure  302  at least partially surrounds certain components, such as CPUs  310  and memory  370  of the device  300 . 
     In some embodiments, the multifunction device shown in  FIG.  3 C  includes one or more tactile output generators  357  as shown in  FIG.  3 A . 
       FIG.  3 D  is a perspective view of an input device  332  (e.g., a trackpad) incorporating a touch-sensitive surface separate from a multifunction device in accordance with some embodiments. In some embodiments, the input device  332  includes touch-sensitive surface  334  and one or more of: one or more intensity sensors  336 , one or more tactile output generators  338 , one or more processors  342 , a communication module  344 , and sensors  346 , as shown in  FIG.  3 B . In some embodiments, the input device  332  is coupled to the device  300  shown in  FIG.  3 C  using wireless or wired communication protocols (e.g., through the external port  124  of the device  300 ). 
       FIG.  3 E  is a simplified block diagram of an exemplary multifunction device that includes a trackpad (e.g., trackpad  332  in  FIG.  3 B ) in accordance with some embodiments. 
     The trackpad  332  includes one or more of: a touch-sensitive surface  334 , one or more intensity sensors  336 , one or more tactile output generators  338 , and a communication module  344 , as described above with respect to  FIG.  3 E . In some of the embodiments in which the trackpad  332  includes one or more processors  342 , the trackpad  332  includes a firmware  348  that includes instructions for execution by the one or more processors  342  to process signals from the touch-sensitive surface  334  and/or the intensity sensors  336  and operate the tactile output generators  338 . In some embodiments, the one or more processors  342  process raw signals from the touch-sensitive surface  334  and/or the intensity sensors  336  and transmit processed information (e.g., coordinates of contacts and intensity of contacts, etc.) to the processors  310  for further processing (e.g., in accordance with the operating system  126 , device drivers  127 , and/or the applications  136 ), such as identifying a touch gesture and normalizing the intensity of contacts. In some embodiments, the processed information is sent via the peripherals interface  118  from the communication module  344  to the processors  310 . In some embodiments, the processed information is transmitted by the processors  342  to the processors  310  without sending the raw signals from the touch-sensitive surface  334  and/or the intensity sensors  336 . In some embodiments, the one or more processors  342  further process the processed information to obtain mapped information (e.g., information for an identified gesture, normalized intensity, etc.) and sends the mapped information to the processors  310 . This reduces the work load of the processors  310 . In some embodiments, the processors  310  are multi-purpose processing units (e.g., CPUs, APUs, etc.) and the processors  342  are application-specific processing units (e.g., application-specific integrated circuits (ASICs)) and/or field-programmable gate arrays (FPGA), which may be more power efficient than multi-purpose processing units. 
     In some embodiments, information received through the peripherals interface  118  is processed by the processors  310  using the communication module  128 , and then using the device drivers  127 . For example, information based on signals measured by the touch-sensitive surface  334  is routed to a device driver that corresponds to the touch-sensitive surface  334 , and information based on signals measured by the one or more intensity sensors  336  is routed to a device driver that corresponds to the one or more intensity sensors  336 . In some embodiments, a single device driver that corresponds to the trackpad  332  includes instructions for handling the information based on signals measured by the touch-sensitive surface  334  and the information based on signals measured by the one or more intensity sensors  336 . 
     In some embodiments, the processors  310  sends instructions to the trackpad  332  (e.g., in accordance with the applications  136 ) to generate a tactile output using a device driver that corresponds to the tactile output generators  338 . 
     In some embodiments, the device drivers  127  are separate from the operating system  126  as illustrated in  FIG.  3 E . In some embodiments, the device drivers  127  are included in the operating system  126 . In some embodiments, the communication module  128  is separate from the operating system  126 . In some embodiments, the communication module  128  is included in the operating system  126 . 
       FIG.  3 F  is a simplified block diagram illustrating architecture of an exemplary multifunction device in accordance with some embodiments. 
     Hardware (e.g., electronic circuitry)  352  of the device is at the base level of the architecture. Hardware  352  can include various hardware interface components, such as the components depicted in  FIGS.  1 A,  3 A and/or  3 B . For example, Hardware  352  includes Touch-Sensitive Surface  334  and the one or more Intensity Sensors  336  described above with respect to  FIGS.  1 A,  3 A,  3 B, and  3 E . At least some of the other elements ( 348 ,  126 ,  356 , and  136 ) of the architecture are software procedures, or portions of software procedures, that process inputs received from Hardware  352  and generate various outputs that are presented through a hardware user interface (e.g., one or more of a display, speakers, device vibration actuator, etc.). 
     Firmware  348  is used to communicate with Hardware  352 . In some embodiments, Firmware  348  includes device drivers. Firmware  348  is used to receive and process input data received from Hardware  352 . In some embodiments, at least a portion of Hardware  352  and Firmware  348  is implemented in Trackpad  332 . 
     In some embodiments, Operating System (“OS”)  126  communicates with Firmware  348 . OS  126  can process raw input data or processed data received from Firmware  348 . 
     Application Programming Interfaces (“APIs”)  356  are software procedures that are used to communicate with OS  126  (or Device Drivers  127  of  FIG.  3 E ). In some embodiments, APIs  356  are included in the device&#39;s operating system, but at a level above its core OS. APIs  356  are designed for use by Applications  136  running on the electronic devices or apparatuses discussed herein. Application software  136  includes one or more applications  136  ( FIGS.  1 A,  3 A, and  3 B ). 
     While each layer in the architecture can utilize the layer underneath it, that is not always required. For example, in some embodiments, Applications  136  may directly communicate with OS  126 . In some embodiments, Applications  136  and API  356  cannot directly access Firmware  348  or Hardware  352 , as these layers are considered private. Applications  136  usually direct calls API  356 , which in turn, accesses OS  126 , Firmware  348 , and Hardware  352 . 
       FIG.  3 G  is a block diagram illustrating data structures used by an exemplary multifunction device in accordance with some embodiments. 
     In  FIG.  3 G , application  136  communicates with contact motion module  130 . In some embodiments, contact motion module  130  is implemented in OS  126 . In some embodiments, contact motion module  130  is separate from OS  126 . In some embodiments, contact motion module  130  is implemented in firmware  348  ( FIG.  3 E ). 
     In some embodiments, contact module  130  includes event sorter  170  ( FIG.  1 B ). In some embodiments, contact intensity module  130  includes contact intensity module  175  that detects intensity of a contact on a touch-sensitive surface. 
     In some embodiments, contact motion module  130  stores a plurality of intensity models  454 . In some embodiments, the plurality of intensity models  454  (e.g., two or more intensity models, or alternatively three or more intensity models) is used by contact intensity module  175 . A respective intensity model in the plurality of intensity models  454  includes one or more of the following, or a superset or subset thereof:
         Intensity Model Identifier  456 , which identifies (typically uniquely identifies) an intensity model (see Appendix A for exemplary intensity models and corresponding intensity model identifiers);   Use Info  458 - 1 , which includes information that identifies conditions for which the corresponding intensity model is configured for use and/or conditions for which the corresponding intensity model is prohibited for use (e.g., for particular applications identified by Application Identity  487 , and/or for particular Regions  488  of a user interface and/or a touch-sensitive surface), and/or one or more priorities  489  associated with the corresponding intensity model; and   Intensity Thresholds  464 , which is described in further detail below.       

     In some embodiments, intensity thresholds  464  include one or more intensity thresholds for one or more intensity stages (e.g.,  466 - 1 ,  466 - 2 , etc.). For example, intensity thresholds  464  include an activation threshold  468 - 1  for entering a respective intensity stage. In some embodiments, intensity thresholds  464  include a release threshold  468 - 2  for exiting from the respective intensity stage. In some embodiments, the release threshold  468 - 2  for the respective intensity stage is identical to the activation threshold  468 - 1  for the respective intensity stage. In some embodiments, the release threshold  468 - 2  for the respective intensity stage is distinct from the activation threshold  468 - 1  for the respective intensity stage. In some embodiments, intensity thresholds  464  include one or more transition intensity thresholds  468 - 3 . For example, intensity thresholds  464  may include a transition intensity threshold associated with the activation threshold  468 - 1 , which is used to indicate that a contact of certain intensity is in a transition range from the activation threshold  468 - 1 . Additionally or alternatively, intensity thresholds  464  may include a transition intensity threshold associated with the release threshold  468 - 2 , which is used to indicate that a contact of certain intensity is in a transition range from the release threshold  468 - 2 . In some embodiments, intensity thresholds  464  include tactile output parameters  468 - 2 , which indicate whether or not a tactile output is to be generated that intensity of a contact crosses one of the intensity thresholds and, if a tactile output is to be generated, what type of a tactile output is to be generated (e.g., intensity, duration, and waveform of the tactile output). 
     In some embodiments, information sent by application  136  to contact motion module  130  (especially contact intensity module  175  of contact motion module  130 ) includes one or more of the following, or a subset or superset thereof:
         Intensity Model Identifier  490 , which identifies which intensity model is to be used by contact intensity module  175 ;   Tracking Region  492 , which identifies a region for which a particular intensity model is to be used;   Tactile Output Trigger  494 , which initiates generation of a tactile output by one or more tactile output generators controlled by contact motion module  130 ;   Application Identity  496 , which identifies application  136  that sends the information; and   Device Identifier  498 , which identifies an input device (e.g., a touchpad or a trackpad) that will use the identified intensity model and/or generate a tactile output.       

     In some embodiments, information sent by contact motion module  130  (especially contact intensity module  175  of contact motion module  130 ) includes one or more of the following, or a subset or superset thereof:
         Availability Information  474 , which indicates whether an input device (e.g., a touch pad or a trackpad) is configured to provide intensity information;   Characterization Parameters  476 , such as Intensity Stage  478  and/or one or more Progress Values  480  (e.g., Stage Progress Value  482  and Transition Progress Value  484 );   Intensity Model Identifier  485 , which indicates an intensity model used by the contact intensity module  175  (e.g., for determining characterization parameters  476 );   Device Identifier  486 , which identifies an input device from which intensity signals have been received (e.g., for determining characterization parameters  476 ); and   Other Touch Information (e.g., gesture type, number of contacts, time stamp, etc.).       

     These information to and/or from contact motion module  130  need not be transmitted concurrently. For example, in some embodiments, availability information  474  is sent, separately from characterization parameters  476 , by contact intensity module  175 . In another example, tactile output trigger  494  is transmitted separately from tracking region  492 , in some embodiments. 
     In some embodiments, information exchanged between application  136  and contact/motion module  130  is transmitted through Application Programming Interface(s)  356  ( FIG.  3 F ). 
     Although  FIG.  3 G  illustrates communication between contact motion module  130  and application  136 , contact motion module  130  can be in communication with multiple different applications  136  (e.g., contacts module  137 , telephone module  138 , video conference module  139 , e-mail client module  140 , instant messaging module  141 , workout support module  142 , camera module  143 , image management module  144 , browser module  147 , calendar module  148 , widget modules  149 , search module  151 , video and music player module  152 , drawing module  380 , presentation module  382 , word processing module  384 , website creation module  386 , disk authoring module  388 , spreadsheet module  390 ) that are configured to receive contact information (e.g., touch events that include contact information). In some embodiments, contact motion module  130  is also in communication with third party applications. In some embodiments, contact motion module  130  controls, for multiple applications, how press inputs are interpreted (e.g., changing intensity thresholds). This allows press inputs to be interpreted consistently across the multiple applications (e.g., providing consistent trackpad configurations, and/or providing consistent tactile outputs). 
     Attention is now directed towards embodiments of user interfaces (“UI”) that are, optionally, implemented on portable multifunction device  100 . 
       FIG.  4 A  illustrates an exemplary user interface for a menu of applications on portable multifunction device  100  in accordance with some embodiments. Similar user interfaces are, optionally, implemented on device  300 . In some embodiments, user interface  400  includes the following elements, or a subset or superset thereof:
         Signal strength indicator(s)  402  for wireless communication(s), such as cellular and Wi-Fi signals;   Time  404 ;   Bluetooth indicator  405 ;   Battery status indicator  406 ;   Tray  408  with icons for frequently used applications, such as:
           Icon  416  for telephone module  138 , labeled “Phone,” which optionally includes an indicator  414  of the number of missed calls or voicemail messages;   Icon  418  for e-mail client module  140 , labeled “Mail,” which optionally includes an indicator  410  of the number of unread e-mails;   Icon  420  for browser module  147 , labeled “Browser;” and   Icon  422  for video and music player module  152 , also referred to as iPod (trademark of Apple Inc.) module  152 , labeled “iPod;” and   
           Icons for other applications, such as:
           Icon  424  for IM module  141 , labeled “Messages;”   Icon  426  for calendar module  148 , labeled “Calendar;”   Icon  428  for image management module  144 , labeled “Photos;”   Icon  430  for camera module  143 , labeled “Camera;”   Icon  432  for online video module  155 , labeled “Online Video;”   Icon  434  for stocks widget  149 - 2 , labeled “Stocks;”   Icon  436  for map module  154 , labeled “Maps;”   Icon  438  for weather widget  149 - 1 , labeled “Weather;”   Icon  440  for alarm clock widget  149 - 4 , labeled “Clock;”   Icon  442  for workout support module  142 , labeled “Workout Support;”   Icon  444  for notes module  153 , labeled “Notes;” and   Icon  446  for a settings application or module, which provides access to settings for device  100  and its various applications  136 .   
               

     It should be noted that the icon labels illustrated in  FIG.  4 A  are merely exemplary. For example, in some embodiments, icon  422  for video and music player module  152  is labeled “Music” or “Music Player.” Other labels are, optionally, used for various application icons. In some embodiments, a label for a respective application icon includes a name of an application corresponding to the respective application icon. In some embodiments, a label for a particular application icon is distinct from a name of an application corresponding to the particular application icon. 
       FIG.  4 B  illustrates an exemplary user interface on a device (e.g., device  300 ,  FIG.  3 A or  3 B ) with a touch-sensitive surface  451  (e.g., a tablet or touchpad  355 ,  FIG.  3 A or  3 B ) that is separate from the display  450 . Device  300  also, optionally, includes one or more contact intensity sensors (e.g., one or more of sensors  359 ) for detecting intensity of contacts on touch-sensitive surface  451  and/or one or more tactile output generators  357  for generating tactile outputs for a user of device  300 . 
       FIG.  4 B  illustrates an exemplary user interface on a device (e.g., device  300 ,  FIG.  3 A or  3 B ) with a touch-sensitive surface  451  (e.g., a tablet or touchpad  355 ,  FIG.  3 A or  3 B ) that is separate from the display  450 . Many of the examples that follow will be given with reference to a device that detects inputs on a touch-sensitive surface that is separate from the display, as shown in  FIG.  4 B . In some embodiments, the touch-sensitive surface (e.g.,  451  in  FIG.  4 B ) has a primary axis (e.g.,  452  in  FIG.  4 B ) that corresponds to a primary axis (e.g.,  453  in  FIG.  4 B ) on the display (e.g.,  450 ). In accordance with these embodiments, the device detects contacts (e.g.,  460  and  462  in  FIG.  4 B ) with the touch-sensitive surface  451  at locations that correspond to respective locations on the display (e.g., in  FIG.  4 B,  460    corresponds to  468  and  462  corresponds to  470 ). In this way, user inputs (e.g., contacts  460  and  462 , and movements thereof) detected by the device on the touch-sensitive surface (e.g.,  451  in  FIG.  4 B ) are used by the device to manipulate the user interface on the display (e.g.,  450  in  FIG.  4 B ) of the multifunction device when the touch-sensitive surface is separate from the display. It should be understood that similar methods are, optionally, used for other user interfaces described herein. 
     Additionally, while the following examples are given primarily with reference to finger inputs (e.g., finger contacts, finger tap gestures, finger swipe gestures, etc.), it should be understood that, in some embodiments, one or more of the finger inputs are replaced with input from another input device (e.g., a mouse based input or a stylus input). For example, a swipe gesture is, optionally, replaced with a mouse click (e.g., instead of a contact) followed by movement of the cursor along the path of the swipe (e.g., instead of movement of the contact). As another example, a tap gesture is, optionally, replaced with a mouse click while the cursor is located over the location of the tap gesture (e.g., instead of detection of the contact followed by ceasing to detect the contact). Similarly, when multiple user inputs are simultaneously detected, it should be understood that multiple computer mice are, optionally, used simultaneously, or a mouse and finger contacts are, optionally, used simultaneously. 
     As used herein, the term “focus selector” refers to an input element that indicates a current part of a user interface with which a user is interacting. In some implementations that include a cursor or other location marker, the cursor acts as a “focus selector,” so that when an input (e.g., a press input) is detected on a touch-sensitive surface (e.g., touchpad  355  in  FIG.  3 A or  3 B  or touch-sensitive surface  451  in  FIG.  4 B ) while the cursor is over a particular user interface element (e.g., a button, window, slider or other user interface element), the particular user interface element is adjusted in accordance with the detected input. In some implementations that include a touch-screen display (e.g., touch-sensitive display system  112  in  FIG.  1 A  or the touch screen in  FIG.  4 A ) that enables direct interaction with user interface elements on the touch-screen display, a detected contact on the touch-screen acts as a “focus selector,” so that when an input (e.g., a press input by the contact) is detected on the touch-screen display at a location of a particular user interface element (e.g., a button, window, slider or other user interface element), the particular user interface element is adjusted in accordance with the detected input. In some implementations, focus is moved from one region of a user interface to another region of the user interface without corresponding movement of a cursor or movement of a contact on a touch-screen display (e.g., by using a tab key or arrow keys to move focus from one button to another button); in these implementations, the focus selector moves in accordance with movement of focus between different regions of the user interface. Without regard to the specific form taken by the focus selector, the focus selector is generally the user interface element (or contact on a touch-screen display) that is controlled by the user so as to communicate the user&#39;s intended interaction with the user interface (e.g., by indicating, to the device, the element of the user interface with which the user is intending to interact). For example, the location of a focus selector (e.g., a cursor, a contact, or a selection box) over a respective button while a press input is detected on the touch-sensitive surface (e.g., a touchpad or touch screen) will indicate that the user is intending to activate the respective button (as opposed to other user interface elements shown on a display of the device). 
     As used in the specification and claims, the term “intensity” of a contact on a touch-sensitive surface refers to the force or pressure (force per unit area) of a contact (e.g., a finger contact or a stylus contact) on the touch-sensitive surface, or to a substitute (proxy) for the force or pressure of a contact on the touch-sensitive surface. The intensity of a contact has a range of values that includes at least four distinct values and more typically includes hundreds of distinct values (e.g., at least 256). Intensity of a contact is, optionally, determined (or measured) using various approaches and various sensors or combinations of sensors. For example, one or more force sensors underneath or adjacent to the touch-sensitive surface are, optionally, used to measure force at various points on the touch-sensitive surface. In some implementations, force measurements from multiple force sensors are combined (e.g., a weighted average or a sum) to determine an estimated force of a contact. Similarly, a pressure-sensitive tip of a stylus is, optionally, used to determine a pressure of the stylus on the touch-sensitive surface. Alternatively, the size of the contact area detected on the touch-sensitive surface and/or changes thereto, the capacitance of the touch-sensitive surface proximate to the contact and/or changes thereto, and/or the resistance of the touch-sensitive surface proximate to the contact and/or changes thereto are, optionally, used as a substitute for the force or pressure of the contact on the touch-sensitive surface. In some implementations, the substitute measurements for contact force or pressure are used directly to determine whether an intensity threshold has been exceeded (e.g., the intensity threshold is described in units corresponding to the substitute measurements). In some implementations, the substitute measurements for contact force or pressure are converted to an estimated force or pressure and the estimated force or pressure is used to determine whether an intensity threshold has been exceeded (e.g., the intensity threshold is a pressure threshold measured in units of pressure). Using the intensity of a contact as an attribute of a user input allows user access to additional device functionality that may otherwise not be readily accessible by the user on a reduced-size device with limited real estate for displaying affordances (e.g., on a touch-sensitive display) and/or receiving user input (e.g., via a touch-sensitive display, a touch-sensitive surface, or a physical/mechanical control such as a knob or a button). 
     In some embodiments, contact/motion module  130  uses a set of one or more intensity thresholds to determine whether an operation has been performed by a user (e.g., to determine whether a user has “clicked” on an icon). In some embodiments, at least a subset of the intensity thresholds are determined in accordance with software parameters (e.g., the intensity thresholds are not determined by the activation thresholds of particular physical actuators and can be adjusted without changing the physical hardware of device  100 ). For example, a mouse “click” threshold of a trackpad or touch-screen display can be set to any of a large range of predefined thresholds values without changing the trackpad or touch-screen display hardware. Additionally, in some implementations a user of the device is provided with software settings for adjusting one or more of the set of intensity thresholds (e.g., by adjusting individual intensity thresholds and/or by adjusting a plurality of intensity thresholds at once with a system-level click “intensity” parameter). 
     As used in the specification and claims, the term “characteristic intensity” of a contact refers to a characteristic of the contact based on one or more intensities of the contact. In some embodiments, the characteristic intensity is based on multiple intensity samples. The characteristic intensity is, optionally, based on a predefined number of intensity samples, or a set of intensity samples collected during a predetermined time period (e.g., 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10 seconds) relative to a predefined event (e.g., after detecting the contact, prior to detecting liftoff of the contact, before or after detecting a start of movement of the contact, prior to detecting an end of the contact, before or after detecting an increase in intensity of the contact, and/or before or after detecting a decrease in intensity of the contact). A characteristic intensity of a contact is, optionally based on one or more of: a maximum value of the intensities of the contact, a mean value of the intensities of the contact, an average value of the intensities of the contact, a top 10 percentile value of the intensities of the contact, a value at the half maximum of the intensities of the contact, a value at the 90 percent maximum of the intensities of the contact, or the like. In some embodiments, the duration of the contact is used in determining the characteristic intensity (e.g., when the characteristic intensity is an average of the intensity of the contact over time). In some embodiments, the characteristic intensity is compared to a set of one or more intensity thresholds to determine whether an operation has been performed by a user. For example, the set of one or more intensity thresholds may include a first intensity threshold and a second intensity threshold. In this example, a contact with a characteristic intensity that does not exceed the first threshold results in a first operation, a contact with a characteristic intensity that exceeds the first intensity threshold and does not exceed the second intensity threshold results in a second operation, and a contact with a characteristic intensity that exceeds the second intensity threshold results in a third operation. In some embodiments, a comparison between the characteristic intensity and one or more intensity thresholds is used to determine whether or not to perform one or more operations (e.g., whether to perform a respective option or forgo performing the respective operation) rather than being used to determine whether to perform a first operation or a second operation. 
     In some embodiments, a portion of a gesture is identified for purposes of determining a characteristic intensity. For example, a touch-sensitive surface may receive a continuous swipe contact transitioning from a start location and reaching an end location (e.g., a drag gesture), at which point the intensity of the contact increases. In this example, the characteristic intensity of the contact at the end location may be based on only a portion of the continuous swipe contact, and not the entire swipe contact (e.g., only the portion of the swipe contact at the end location). In some embodiments, a smoothing algorithm may be applied to the intensities of the swipe contact prior to determining the characteristic intensity of the contact. For example, the smoothing algorithm optionally includes one or more of: an unweighted sliding-average smoothing algorithm, a triangular smoothing algorithm, a median filter smoothing algorithm, and/or an exponential smoothing algorithm. In some circumstances, these smoothing algorithms eliminate narrow spikes or dips in the intensities of the swipe contact for purposes of determining a characteristic intensity. 
     The user interface figures (e.g.,  FIGS.  5 A- 5 TT ) described below optionally include various intensity diagrams that show the current intensity of the contact on the touch-sensitive surface relative to one or more intensity thresholds (e.g., a contact detection intensity threshold IT 0 , a latching intensity threshold IT L , an activation intensity threshold IT A , and/or one or more other intensity thresholds). This intensity diagram is typically not part of the displayed user interface, but is provided to aid in the interpretation of the figures. In some embodiments, a light press intensity threshold (e.g., a lower intensity threshold) corresponds to an intensity at which the device will perform operations typically associated with clicking a button of a physical mouse or a trackpad. In some embodiments, a deep press intensity threshold (e.g., a higher intensity threshold) corresponds to an intensity at which the device will perform operations that are different from operations typically associated with clicking a button of a physical mouse or a trackpad. In some embodiments, when a contact is detected with a characteristic intensity below the light press intensity threshold (e.g., and above a nominal contact-detection intensity threshold IT 0  below which the contact is no longer detected), the device will move a focus selector in accordance with movement of the contact on the touch-sensitive surface without performing an operation associated with the light press intensity threshold or the deep press intensity threshold. Generally, unless otherwise stated, these intensity thresholds are consistent between different sets of user interface figures. 
     In some embodiments, the response of the device to inputs detected by the device depends on criteria based on the contact intensity during the input. For example, for some “light press” inputs, the intensity of a contact exceeding a first intensity threshold during the input triggers a first response. In some embodiments, the response of the device to inputs detected by the device depends on criteria that include both the contact intensity during the input and time-based criteria. For example, for some “deep press” inputs, the intensity of a contact exceeding a second intensity threshold during the input, greater than the first intensity threshold for a light press, triggers a second response only if a delay time has elapsed between meeting the first intensity threshold and meeting the second intensity threshold. This delay time is typically less than 200 ms in duration (e.g., 40, 100, or 120 ms, depending on the magnitude of the second intensity threshold, with the delay time increasing as the second intensity threshold increases). This delay time helps to avoid accidental deep press inputs. As another example, for some “deep press” inputs, there is a reduced-sensitivity time period that occurs after the time at which the first intensity threshold is met. During the reduced-sensitivity time period, the second intensity threshold is increased. This temporary increase in the second intensity threshold also helps to avoid accidental deep press inputs. For other deep press inputs, the response to detection of a deep press input does not depend on time-based criteria. 
     In some embodiments, one or more of the input intensity thresholds and/or the corresponding outputs vary based on one or more factors, such as user settings, contact motion, input timing, application running, rate at which the intensity is applied, number of concurrent inputs, user history, environmental factors (e.g., ambient noise), focus selector position, and the like. Exemplary factors are described in U.S. patent application Ser. Nos. 14/399,606 and 14/624,296, which are incorporated by reference herein in their entireties. 
     For example,  FIG.  4 C  illustrates a dynamic intensity threshold  480  that changes over time based in part on the intensity of touch input  476  over time. Dynamic intensity threshold  480  is a sum of two components, first component  474  that decays over time after a predefined delay time p 1  from when touch input  476  is initially detected, and second component  478  that trails the intensity of touch input  476  over time. The initial high intensity threshold of first component  474  reduces accidental triggering of a “deep press” response, while still allowing an immediate “deep press” response if touch input  476  provides sufficient intensity. Second component  478  reduces unintentional triggering of a “deep press” response by gradual intensity fluctuations of a touch input. In some embodiments, when touch input  476  satisfies dynamic intensity threshold  480  (e.g., at point  481  in  FIG.  4 C ), the “deep press” response is triggered. 
       FIG.  4 D  illustrates another dynamic intensity threshold  486  (e.g., intensity threshold I D ).  FIG.  4 D  also illustrates two other intensity thresholds: a first intensity threshold I H  and a second intensity threshold I L . In  FIG.  4 D , although touch input  484  satisfies the first intensity threshold I H  and the second intensity threshold I L  prior to time p 2 , no response is provided until delay time p 2  has elapsed at time  482 . Also in  FIG.  4 D , dynamic intensity threshold  486  decays over time, with the decay starting at time  488  after a predefined delay time p 1  has elapsed from time  482  (when the response associated with the second intensity threshold I L  was triggered). This type of dynamic intensity threshold reduces accidental triggering of a response associated with the dynamic intensity threshold I D  immediately after, or concurrently with, triggering a response associated with a lower intensity threshold, such as the first intensity threshold I H  or the second intensity threshold I L . 
       FIG.  4 E  illustrate yet another dynamic intensity threshold  492  (e.g., intensity threshold I D ). In  FIG.  4 E , a response associated with the intensity threshold I L  is triggered after the delay time p 2  has elapsed from when touch input  490  is initially detected. Concurrently, dynamic intensity threshold  492  decays after the predefined delay time p 1  has elapsed from when touch input  490  is initially detected. So a decrease in intensity of touch input  490  after triggering the response associated with the intensity threshold I L , followed by an increase in the intensity of touch input  490 , without releasing touch input  490 , can trigger a response associated with the intensity threshold I D  (e.g., at time  494 ) even when the intensity of touch input  490  is below another intensity threshold, for example, the intensity threshold I L . 
     An increase of characteristic intensity of the contact from an intensity below the light press intensity threshold to an intensity between the light press intensity threshold and the deep press intensity threshold is sometimes referred to as a “light press” input. An increase of characteristic intensity of the contact from an intensity below the deep press intensity threshold to an intensity above the deep press intensity threshold is sometimes referred to as a “deep press” input. An increase of characteristic intensity of the contact from an intensity below the contact-detection intensity threshold IT 0  to an intensity between the contact-detection intensity threshold IT 0  and the light press intensity threshold IT L  is sometimes referred to as detecting the contact on the touch-surface. A decrease of characteristic intensity of the contact from an intensity above the contact-detection intensity threshold IT 0  to an intensity below the contact-detection intensity threshold IT 0  is sometimes referred to as detecting liftoff of the contact from the touch-surface. In some embodiments IT 0  is zero. In some embodiments, IT 0  is greater than zero. In some illustrations a shaded circle or oval is used to represent intensity of a contact on the touch-sensitive surface. In some illustrations, a circle or oval without shading is used represent a respective contact on the touch-sensitive surface without specifying the intensity of the respective contact. 
     In some embodiments, described herein, one or more operations are performed in response to detecting a gesture that includes a respective press input or in response to detecting the respective press input performed with a respective contact (or a plurality of contacts), where the respective press input is detected based at least in part on detecting an increase in intensity of the contact (or plurality of contacts) above a press-input intensity threshold. In some embodiments, the respective operation is performed in response to detecting the increase in intensity of the respective contact above the press-input intensity threshold (e.g., the respective operation is performed on a “down stroke” of the respective press input). In some embodiments, the press input includes an increase in intensity of the respective contact above the press-input intensity threshold and a subsequent decrease in intensity of the contact below the press-input intensity threshold, and the respective operation is performed in response to detecting the subsequent decrease in intensity of the respective contact below the press-input threshold (e.g., the respective operation is performed on an “up stroke” of the respective press input). 
     In some embodiments, the device employs intensity hysteresis to avoid accidental inputs sometimes termed “jitter,” where the device defines or selects a hysteresis intensity threshold with a predefined relationship to the press-input intensity threshold (e.g., the hysteresis intensity threshold is X intensity units lower than the press-input intensity threshold or the hysteresis intensity threshold is 75%, 90%, or some reasonable proportion of the press-input intensity threshold). Thus, in some embodiments, the press input includes an increase in intensity of the respective contact above the press-input intensity threshold and a subsequent decrease in intensity of the contact below the hysteresis intensity threshold that corresponds to the press-input intensity threshold, and the respective operation is performed in response to detecting the subsequent decrease in intensity of the respective contact below the hysteresis intensity threshold (e.g., the respective operation is performed on an “up stroke” of the respective press input). Similarly, in some embodiments, the press input is detected only when the device detects an increase in intensity of the contact from an intensity at or below the hysteresis intensity threshold to an intensity at or above the press-input intensity threshold and, optionally, a subsequent decrease in intensity of the contact to an intensity at or below the hysteresis intensity, and the respective operation is performed in response to detecting the press input (e.g., the increase in intensity of the contact or the decrease in intensity of the contact, depending on the circumstances). 
     For ease of explanation, the description of operations performed in response to a press input associated with a press-input intensity threshold or in response to a gesture including the press input are, optionally, triggered in response to detecting: an increase in intensity of a contact above the press-input intensity threshold, an increase in intensity of a contact from an intensity below the hysteresis intensity threshold to an intensity above the press-input intensity threshold, a decrease in intensity of the contact below the press-input intensity threshold, or a decrease in intensity of the contact below the hysteresis intensity threshold corresponding to the press-input intensity threshold. Additionally, in examples where an operation is described as being performed in response to detecting a decrease in intensity of a contact below the press-input intensity threshold, the operation is, optionally, performed in response to detecting a decrease in intensity of the contact below a hysteresis intensity threshold corresponding to, and lower than, the press-input intensity threshold. As described above, in some embodiments, the triggering of these responses also depends on time-based criteria being met (e.g., a delay time has elapsed between a first intensity threshold being met and a second intensity threshold being met). 
     User Interfaces and Associated Processes 
     Attention is now directed towards embodiments of user interfaces (“UI”) and associated processes that may be implemented on an electronic device, such as portable multifunction device  100  or device  300 , with a display, a touch-sensitive surface, and one or more sensors to detect intensity of contacts with the touch-sensitive surface. 
       FIGS.  5 A- 5 TT  illustrate exemplary user interfaces for processing touch inputs in accordance with some embodiments. The user interfaces in these figures are used to illustrate the processes described below, including method  600  described below with respect to  FIGS.  6 A- 6 C , method  650  described below with respect to  FIG.  6 D , method  700  described below with respect to  FIGS.  7 A- 7 C , method  750  described below with respect to  FIG.  7 D , method  800  described below with respect to  FIGS.  8 A- 8 C , method  900  described below with respect to  FIGS.  9 A- 9 D , method  1000  described below with respect to  FIGS.  10 A- 10 D , method  1100  described below with respect to  FIGS.  11 A- 11 C , and method  1200  described below with respect to  FIGS.  12 A- 12 C . Although some of the examples which follow will be given with reference to inputs on a touch-sensitive surface  451  that is separate from the display  450 , in some embodiments, the device detects inputs on a touch-screen display (where the touch-sensitive surface and the display are combined), as shown in  FIG.  4 A . 
       FIG.  5 A  illustrates window  506  of an application displayed on display  450  (e.g., display  340 , touch screen  112 ) of a device (e.g., device  300 ,  100 ). The application with which window  506  is associated is an application that displays content, such as an email application. Content, such as document  508 , is displayed in window  506 . Document  508  optionally includes embedded content, attached content, and/or links to other content (for convenience, collectively referred to below as “embedded content”). The embedded content is, optionally, represented by document icons  510 . For example, document  508  includes document icons  510 - 1  and  510 - 2 , each of which corresponds to respective embedded content (e.g., a document) embedded in document  508 . The respective documents corresponding to icons  510 - 1  and  510 - 2  are associated with respective applications. For example, icon  510 - 1  optionally corresponds to a presentation document, which is associated with a presentation application. The document associated with an icon  510  is, optionally, a word processing document, a spreadsheet, a presentation, a drawing, a graphic or image, an audio file, a video file, a text document, or a Portable Document Format document (sometimes referred to as a PDF). 
     Cursor  502  is also displayed on display  450 . Cursor  502  is an example of a focus selector. A user may move cursor  502  on display  450  (e.g., using touch-sensitive surface  451  of the device) to bring focus to an element displayed on display  450  (e.g., a user interface object, an icon, a link, etc.) by moving a contact on touch-sensitive surface  451 .  FIG.  5 A  shows movement of contact  504  down and to the left on touch-sensitive surface  451  that causes the device to move cursor  502  down and to the left on display  450 . 
       FIG.  5 A  also shows that intensity of contact  504  is below a first intensity threshold (e.g., “IT 1 ”). In some embodiments, contact  504  is deemed to be in stage 0 based on a determination that the intensity of contact  504  is below the first intensity threshold. A stage progress value indicates a normalized intensity of contact  504 , where an intensity that corresponds to the first intensity threshold is deemed to correspond to 100% (or 1) stage progress value for stage 0, and an intensity that corresponds to a base intensity threshold or a detection intensity threshold (e.g., “IT 0 ”) is deemed to correspond to 0% (or 0) stage progress value for stage 0. When the intensity of contact  504  increases from a value below the first intensity threshold and approaches the first intensity threshold, the stage progress value increases toward 100%. 
     When the intensity of contact  504  increases from an intensity below the first intensity threshold to an intensity above the first intensity threshold, the device expands icon  510 - 1  to show an animation of converting icon  510 - 1  into preview interface  512  ( FIG.  5 D ). In accordance with a determination that the intensity of contact  504  satisfies (e.g., is above) the first intensity threshold, contact  504  is deemed to be in stage 1. The stage progress value is updated for stage 1. In some embodiments, an intensity that corresponds to the first intensity threshold is deemed to correspond to 0% (or 0) stage progress value for stage 1, and an intensity that corresponds to a second intensity threshold (e.g., “IT 2 ”) is deemed to correspond to 100% (or 1) stage progress value for stage 1. 
       FIG.  5 B  shows that, in response to the detection of increase in intensity of contact  504  above the first intensity threshold, the device shows the animation of converting icon  510 - 1  into preview interface  512  ( FIG.  5 D ). In some embodiments, the stage progress value of contact  504  is used to initiate the animation (e.g., the animation is initiated in response to determining that the stage progress value of contact  504  satisfies predefined criteria). In some embodiments, the transition progress value of contact  504  is used to initiate the animation (e.g., the animation is initiated in response to determining that the transition progress value of contact  504  satisfies predefined criteria) (not shown). 
       FIG.  5 C  shows that, in response to the detection of further increase in intensity of contact  504 , the device shows a further expanded icon  510 . Contact  504  is still deemed to be in stage 1, and the stage progress value has increased further. 
       FIG.  5 C  also shows that a transition progress value has increased from 0%. The transition progress value indicates that contact  504  is within a predefined intensity range from an intensity threshold (e.g., the second intensity threshold). In some cases, the transition progress value also indicates how much additional intensity is required for a stage transition (e.g., from stage 1 to stage 2) in normalized intensity. In some embodiments, the intensity range is defined by a transition range intensity threshold (also called herein a transition intensity threshold) that indicates one end of the intensity range and an activation intensity threshold that indicates an intensity at which a stage transition occurs. In  FIG.  5 C , the transition intensity threshold for a transition from stage 1 to stage 2 is identical to a release intensity threshold “IT 2R ” for stage 2. However, the transition intensity threshold need not be identical to a release intensity threshold. 
       FIG.  5 D  shows that the intensity of contact  504  has increased above the second intensity threshold (e.g., “IT 2 ”). In accordance with a determination that the intensity of contact  504  satisfies (e.g., is above) the second intensity threshold, contact  504  is deemed to be in stage 2. In response, preview interface  512  is displayed. The stage progress value for contact  504  is updated for stage 2. In some embodiments, an intensity that corresponds to the second intensity threshold is deemed to correspond to 0% (or 0) stage progress value for stage 2, and an intensity that corresponds to a third intensity threshold (e.g., “IT 3 ”) is deemed to correspond to 100% (or 1) stage progress value for stage 2. 
       FIG.  5 E  shows further increase in the intensity of contact  504 . Contact  504  has not satisfied the third intensity threshold, and still remains in stage 2. The stage progress value and the transition progress value are increased. 
       FIG.  5 F  shows that the intensity of contact  504  has decreased below the second intensity threshold (e.g., “IT 2 ”), but remains above a release intensity threshold for stage 2 (e.g., “IT 2R ”). In accordance with a determination that the intensity of contact  504  does not satisfy (e.g., remains above) the release intensity threshold for stage 2, contact  504  is deemed to remain in stage 2. Thus, preview interface  512  remains on display. In  FIG.  5 F , the stage progress value is 0% for stage 2, because the intensity of contact  504  is below the second intensity threshold. The transition progress value indicates that the intensity of contact  504  is within a predefined intensity range from the release intensity threshold for stage 2. 
       FIG.  5 G  shows that the intensity of contact  504  has further decreased below the release intensity threshold for stage 2. In accordance with a determination that the intensity of contact  504  satisfies (e.g., is below) the release intensity threshold for stage 2, contact  504  is deemed to be in stage 1. Preview interface  512  ( FIG.  5 F ) ceased to be displayed and an animation that shows a transition from icon  510 - 1  to preview interface  512  is shown in accordance with the intensity of contact  504 . 
       FIG.  5 H  shows that, in some embodiments, a release intensity threshold is identical to an activation intensity threshold (e.g., “IT 1 ”=“IT 1R ”). Thus, the release intensity threshold is not separately shown in  FIG.  5 H . 
       FIG.  5 I  shows that the intensity of contact  504  has significantly increased to satisfy the third intensity threshold (e.g., “IT 3 ”). In accordance with a determination that the intensity of contact  504  satisfies the third intensity threshold, contact  504  is deemed to be in stage 3. In response, preview interface  512  is enlarged to fill window  506 . 
       FIG.  5 J  shows that intensity thresholds have been changed. For example, in some embodiments, the device determines that previously used intensity thresholds are too low for a user (e.g., the user tends to apply high intensity contacts frequently or is found to have difficulty applying low intensity contacts), and updates the intensity thresholds (e.g., increases at least one of the intensity thresholds and/or decreases at least one of the intensity thresholds). In some embodiments, a software application (e.g., a user interface application, such as an email application) determines that the intensity thresholds based on user interactions and/or internal operations (e.g., so as to avoid conflicts with other functions, such as accessibility). In some embodiments, the intensity thresholds are associated with a particular intensity model. Thus, the device switches from a first intensity model (e.g., “normal user” intensity model) to a second intensity model (e.g., “high intensity user” intensity model) that is distinct from the first intensity model to use different intensity thresholds. 
     In  FIG.  5 J , although the intensity of contact  504  has not changed from  FIG.  5 I , due to the change in the intensity thresholds, contact  504  is deemed to be in stage 2. Thus, preview interface  512  ceases to fill window  506  (e.g., preview interface  512  is reduced from the enlarged preview interface  512  shown in  FIG.  5 I ). 
       FIG.  5 K  shows that the intensity of contact  504  has decreased from above the release intensity threshold for stage 2 (“IT 2R-2 ”) to below the release intensity threshold for stage 2. In accordance with a determination that the intensity of contact  504  satisfies (e.g., is below) the release intensity threshold for stage 2, contact  504  is deemed to be in stage 1. In response, preview interface  512  is replaced with an animation showing a transition between preview interface  512  and icon  510 - 1 . 
       FIG.  5 L  shows that the intensity of contact  504  has further decreased to below a previous release intensity threshold for stage 1 (e.g., “IT 1R ”) and above a current release intensity threshold for stage 1 (e.g., “IT 1R-2 ”). In accordance with a determination that the intensity of contact  504  does not satisfy (e.g., remains above) the current release intensity threshold for stage 1, contact 1 is deemed to be in stage 1. If the previous release intensity threshold was to be used, contact  504  would be deemed to be in stage 0 in accordance with a determination that the intensity of contact  504  satisfies the previous release intensity threshold for stage 1. 
       FIG.  5 M  shows that contact  504  ceases to be detected on touch-sensitive surface  451 . In  FIG.  5 M , the intensity thresholds are reset so that previous intensity thresholds are used. For example, in some embodiments, changes to the intensity thresholds expire upon lift-off of a contact from touch-sensitive surface  451  (or alternatively the intensity of the contact falling below the detection intensity threshold IT 0 ). 
       FIGS.  5 N- 5 O  illustrate that subsequent contact  514  is detected on touch-sensitive surface  451 , and contact  514  is processed in accordance with the intensity thresholds that have been reset. 
       FIGS.  5 P- 5 R  illustrate that the intensity thresholds are changed while no contact is detected on touch-sensitive surface  451  (or prior to detecting contact  516 ).  FIGS.  5 P- 5 R  also illustrate that contact  516  is processed in accordance with the changed intensity thresholds. 
     In some embodiments, the intensity thresholds are predefined or preselected for respective regions. For example, in  FIG.  5 S , icon  510 - 1  is associated with a first intensity model that includes a first set of intensity thresholds, and an email icon (e.g.,  546 - 1  through  546 - 7 ) is associated with a second intensity model that is distinct from the first intensity model and includes a second set of intensity thresholds.  FIG.  5 S  also shows that at least a portion of a user interface  518  of a second software application (e.g., a drawing application) is also shown. In  FIG.  5 S , the user interface  518  of the second software application is associated with a third intensity model that is distinct from the first intensity model and the second intensity model and includes a third set of intensity threshold. 
       FIG.  5 T  shows that at least a portion of a user interface of a first software application (e.g., an email application) that includes icons  510 - 1  and  510 - 2  and at least a portion of a user interface  518  of a second software application (e.g., a drawing application) are concurrently displayed. 
       FIG.  5 T  also illustrates a movement of contact  520  from a first location  520 -A on touch-sensitive surface  451  across touch-sensitive surface  451  (e.g., while remaining contact on touch-sensitive surface  451 ) to a second location  520 -B on touch-sensitive surface  451 .  FIG.  5 T  further illustrate a corresponding movement of cursor  502  from a first location  502 -A on display  450  to a second location  502 -B on display  450 . In  FIG.  5 T , the first location  520 -A on touch-sensitive surface  451  corresponds to the first location  502 -A on display  450  and the second location  520 -B on touch-sensitive surface  451  corresponds to the second location  502 -B on display  450 . 
       FIG.  5 U  illustrates a movement of contact  520  from the second location  520 -B on touch-sensitive surface  451  across touch-sensitive surface  451  to the first location  520 -A on touch-sensitive surface  451  and a corresponding movement of cursor  502  from the second location  502 -B on display  450  to the first location  502 -A on display  450 . 
       FIGS.  5 V- 5 W  show that subsequent contact  522  is detected at the first location  522 -A and intensity of contact  522  is increased. In  FIGS.  5 V- 5 W , contact  522  is processed in accordance with a first intensity model that includes a first set of intensity thresholds (e.g., an intensity model associated with icon  510 - 1  or the first location  502 -A on the display). 
       FIG.  5 X  shows that the intensity of contact  522  is reduced (e.g., below any activation intensity threshold for the first location  502 -A on the display) and moved across touch-sensitive surface  451  to the second location  522 -B on touch-sensitive surface  451 .  FIG.  5 X  also shows a corresponding movement of cursor  502  from the first location  502 -A on display  451  to the second location  502 -B on display  450 . 
       FIGS.  5 Y- 5 Z  show that contact  524  is detected at the second location  522 -B on touch-sensitive surface  451  and intensity of contact  524  is increased. In  FIGS.  5 Y- 5 Z , contact  524  is processed in accordance with a second intensity model that is distinct from the first intensity model and includes a second set of intensity thresholds (e.g., an intensity model associated with user interface  518  of the second software application or the second location  502 -B on the display). 
       FIG.  5 AA  illustrates that the intensity of contact  524  is reduced (e.g., below any activation intensity threshold for the second location  502 -B on the display) and moved across touch-sensitive surface  451  to a third location  524 -C on touch-sensitive surface  451 .  FIG.  5 AA  also shows a corresponding movement of cursor  502  from the second location  502 -B on display  451  to the third location  502 -C on display  450 . The third location  502 -C is deemed to correspond to an overlapping region of the user interface of the first software application and the user interface  518  of the second software application. 
       FIG.  5 BB  illustrates that contact  526  is detected at the third location  526 -C on touch-sensitive surface  451 . In some embodiments, contact  526  is processed in accordance with the second intensity model (e.g., associated with user interface  518 , which is the topmost foreground user interface in  FIG.  5 BB ). However, in some other embodiments, contact  526  is processed in accordance with the first intensity model (even though icon  510 - 2  is not displayed on display  450 ) based on the priority of the first intensity model and the priority of the second intensity model (e.g., the first intensity model is selected because the first intensity model has a higher priority than the second intensity model). In some embodiments or in some circumstances, the user interface of the first software application is displayed over user interface  518  as shown in  FIG.  5 CC . 
       FIG.  5 DD  illustrates that contact  528  is detected at the third location  528 -C on touch-sensitive surface  451 . In some embodiments, contact  528  is processed in accordance with the first intensity model (e.g., associated with user interface  518 , which is the topmost foreground user interface in  FIG.  5 DD ). However, in some other embodiments, contact  528  is processed in accordance with the second intensity model (even though the user interface  518  of the second software application is overlaid by the user interface of the first software application at the third location  502 -C on display) based on the priority of the first intensity model and the priority of the second intensity model. Although the priority of the first intensity model was higher than the priority of the second intensity model during the operations illustrated in  FIGS.  5 BB- 5 CC , the priorities may be updated real-time. For example, the first software application and/or the second software application may send a request to process any contact in a particular display or user interface region, which in this example includes the third location  528 -C, in accordance with the second intensity model, and as a result, the contact at the third location  528 -C is processed (e.g., by contact motion module  130 ,  FIG.  3 G ) using the second intensity model. 
       FIGS.  5 FF- 5 JJ  illustrate user interfaces associated with handwriting recognition (e.g., handwritten characters, hand-drawn shapes, etc.) in accordance with some embodiments. 
       FIG.  5 FF  shows a user interface of a word processing software application partially overlaid by handwriting input tool region  540  (e.g., a character input tool region). As shown in  FIGS.  5 FF- 5 JJ , handwriting input tool region  540  includes a plurality of selection regions (e.g., at least some of  532 - 1  through  532 - 8 ) and handwriting input region  530  (e.g., a character input region). A respective selection region (e.g.,  532 - 1 ) on display  450  corresponds to a region (e.g.,  534 - 1 ) on touch-sensitive surface  451 . In addition, handwriting input region  530  on display  450  corresponds region  542  on touch-sensitive surface  451 . In some embodiments, the respective selection region (e.g.,  532 - 1 ) on display  450  is associated with an intensity model that defines two or more intensity stages (e.g., a state indicating that a contact is detected but a corresponding user interface element has not been activated, and a state indicating that a contact is detected and the corresponding user interface element has been activated). In some embodiments, tactile outputs are enabled for the intensity model associated with the respective selection region. For example, a press input (with sufficient intensity) will trigger a tactile output, which indicates that intensity of the press input is sufficient to activate a corresponding user interface element. 
       FIG.  5 FF  also shows that contact  536  is detected in region  542  of touch-sensitive surface  451  and moved across touch-sensitive surface  451  along a particular path. In some embodiments, region  542  of touch-sensitive surface  451  is associated with an intensity model that has a single stage for which tactile outputs are suppressed. This prevents tactile outputs from interfering with a user&#39;s writing/drawing on the touch-sensitive surface. In some embodiments, for a contact that is initially detected on region  542  of touch-sensitive surface  451 , tactile outputs are suppressed even if the contact moves across touch-sensitive surface  451  to a region (e.g.,  534 - 1 ) that corresponds to a respective selection region (e.g.,  532 - 1 ). This “latching” feature is described further below with respect to  FIGS.  5 KK- 5 TT . 
     In some embodiments, for a contact starting from the region  542 , tactile outputs are suppressed even when the contact moves to a location that corresponds to a selection region on display. 
       FIG.  5 GG  shows that graphical element  544  that corresponds to the particular path of contact  536  is displayed in handwriting input region  530 . In some embodiments, a width of graphical element  544  varies along its path based on one or more measured characteristics of contact  536  in region  542  of touch-sensitive surface  451  while contact  536  follows the particular path. In some embodiments, the width is determined based on intensity and/or a speed of contact  536 . In some embodiments, the width is increased when the intensity of contact  536  increases. In some embodiments, the width is reduced when the speed of contact  536  increases. 
       FIG.  5 GG  also shows that a plurality of selection regions  532 - 5  through  532 - 8  is displayed. Each of selection regions  532 - 5  through  532 - 8  includes a character that is selected based on graphical element  544 . For example, characters in selection regions  532 - 5  through  532 - 8  are selected in accordance with (e.g., that best match) the shape of graphical element  544  (e.g., that best match one or more characteristics of the shape of graphical element  544 ). 
       FIG.  5 HH  shows that contact  538  is detected on region  534 - 8  of touch-sensitive surface  451 , which corresponds to selection region  532 - 8 . Contact  538  is processed using an intensity model that is associated with region  534 - 8 . For example, a tactile output is generated when intensity of contact  538  crosses one or more thresholds of the intensity model associated with region  534 - 8 . In  FIG.  5 HH , a character shown in selection region  532 - 8  is displayed in the user interface of the word processing software application (and inserted into a document of the word processing software application). 
       FIG.  5 II  shows the path of contact  536  on touch-sensitive surface  451 , discussed above with respect to  FIG.  5 FF . In  FIG.  5 II , shown to the right side of touch-sensitive surface  451  is an intensity graph that illustrates intensity of contact  536  over time while contact  536  follows the path on touch-sensitive surface  451 . The graph shows that the intensity of contact  536  starts from below a drawing intensity threshold ITS, increases above the drawing intensity threshold, and falls below the drawing intensity threshold. In some embodiments, once the intensity of contact  536  satisfies (is above) the drawing intensity threshold, contact  536  continues to be processed even if the intensity of contact  536  falls below the drawing intensity threshold. For example, a portion of the path in which the contact has intensity below the drawing intensity threshold is used to extend or update the graphical element  544 . However, in some embodiments, the intensity of contact  536  needs to satisfy the drawing intensity threshold to initiate display of a graphical element. 
       FIG.  5 JJ  shows that contact  536  ceases to be detected while following the path on touch-sensitive surface  451 .  FIG.  5 JJ  also shows that contact  538  is detected on touch-sensitive surface  451 , continuing the path. For example, contact  536  may be slightly lifted-off while drawing the path on touch-sensitive surface  451  and quickly brought back into contact with touch-sensitive surface  451  to complete the path. In some embodiments, a brief absence of contact with touch-sensitive surface  451  is ignored and the path of contact  536  and the path of contact  544  are merged to form a single continuous path. In some embodiments, the merger of the two paths is performed based on a time interval between the lift-off of contact  536  and the detection of contact  544  satisfying predefined timing criteria (e.g., less than 0.1 second, 0.2, second, 0.5, second, etc.). In some other embodiments, the path of contact  536  and the path of contact  544  are maintained separately. In some embodiments, the path of contact  544  is initiated in response to determining that intensity of contact  544  satisfies the drawing intensity threshold (e.g., instead of contact  544  merely contacting touch-sensitive surface  451 ). 
     Although  FIGS.  5 FF- 5 JJ  are described above with respect to recognition of handwritten characters, similar methods, devices, and user interfaces may be used for recognition of hand drawn content (sometimes called or including handwritten content) of a different type (e.g., recognition of shapes or a combination of shapes and characters/letters). 
     In addition, although  FIGS.  5 FF- 5 JJ  illustrate a user interface of a handwriting input tool region with a plurality of selection regions, in some embodiments, a drawing region without any selection regions is used. For example, when character recognition (or shape recognition) is not needed, the plurality of selection regions may be omitted. In some embodiments, a single intensity model is used for the entire handwriting input tool region. 
       FIGS.  5 KK- 5 TT  illustrate latching of touch inputs in accordance with some embodiments. 
       FIG.  5 KK  shows a window  506  that includes a user interface of a software application (e.g., an email application). The user interface in window  506  includes a plurality of regions (e.g., email regions  546 - 1  through  546 - 7 , icons  510 - 1 , and  510 - 2 ). Some of these regions are associated with different intensity models. For example, icon  510 - 1  is associated with a first intensity model and region  546 - 7  is associated with a second intensity model that is distinct from the first intensity model. 
       FIG.  5 LL  shows contact  548  is detected at location  548 -A on touch-sensitive surface  451  that corresponds to icon  510 - 1  on display  450 . In  FIG.  5 LL , icon  510 - 1  is visually distinguished to indicate the detection of contact  548  on touch-sensitive surface  451 . 
       FIGS.  5 MM- 5 PP  show operations associated with a movement of a contact without latching to a region of a user interface in accordance with some embodiments. 
       FIG.  5 MM  shows that intensity of contact  548  has increased and icon  510 - 1  is further visually distinguished to indicate increase in the intensity of contact  548 . 
       FIG.  5 NN  shows that the intensity of contact  548  has been reduced and icon  510 - 1  is visually distinguished to indicate decrease in the intensity of contact  548 .  FIG.  5 NN  also shows that a movement of contact  548  across touch-sensitive surface  451  to location  548 -B on touch-sensitive surface  451 , and a corresponding movement of cursor  502  to region  546 - 7  on display  450 . Prior to the movement of contact  548  to location  548 -B on touch-sensitive surface  451 , the intensity of contact  548  has not satisfied a latching intensity threshold (e.g., “IT L ”) for icon  510 - 1 . 
       FIG.  5 OO  shows that, in response to the movement of cursor  502  to region  546 - 7  on display  450 , visual distinction of icon  510 - 1  is removed and region  546 - 7  is visually distinguished to indicate detection of contact  548  at a location  548 -B that correspond to region  546 - 7  on display  450 . 
       FIG.  5 PP  shows that the intensity of contact  548  has increased above the activation intensity threshold (e.g., “IT A ”) for region  546 - 7 . In response, region  546 - 7  is visually distinguished to indicate that region  546 - 7  has been activated. In addition, the visual distinction of region  546 - 2 , which was previously activated, is removed.  FIG.  5 PP  also shows that window  506  is updated to show content of Email  7  that corresponds to region  546 - 7 . 
       FIGS.  5 QQ- 5 TT  show operations associated with a movement of a contact while latched to a region of a user interface in accordance with some embodiments. 
       FIG.  5 QQ  shows that the intensity of contact  548  has increased to satisfy the latching intensity threshold (e.g., “IT L ”) for icon  510 - 1 .  FIG.  5 QQ  also illustrates that icon  510 - 1  is further visually distinguished to indicate that cursor  502  is latched to icon  510 - 1 . 
       FIG.  5 RR  shows a movement of contact  548  across touch-sensitive surface  451  to location  548 -B on touch-sensitive surface  451  while maintaining intensity above the latching intensity threshold (e.g., “IT L ”) for icon  510 - 1 , and a corresponding movement of cursor  502  to region  546 - 7  on display  450 . In  FIG.  5 RR , although the intensity of contact  548  would satisfy the activation intensity threshold (e.g., “IT A ”) for region  546 - 7 , region  546 - 7  is not activated because cursor  502  is latched to icon  510 - 1 . 
       FIG.  5 SS  shows that the intensity of contact  548  has further increased to satisfy an activation intensity threshold (e.g., “IT A ”) for icon  510 - 1 , which activates icon  510 - 1  even though cursor  502  is located in region  546 - 7 . 
       FIG.  5 TT  shows that, in response to the intensity of contact  548  satisfying the activation intensity threshold (e.g., “IT A ”) for icon  510 - 1 , icon  510 - 1  is activated. In  FIG.  5 TT , preview interface  512  is displayed in response to the intensity of contact  548  satisfying the activation intensity threshold (e.g., “IT A ”) for icon  510 - 1 . 
       FIGS.  6 A- 6 C  illustrate a flow diagram of a method  600  of processing a touch input based on an intensity stage of the touch input in accordance with some embodiments. The method  600  is performed at an electronic device (e.g., device  300 ,  FIG.  3 A or  3 B , or portable multifunction device  100 ,  FIG.  1 A ) with a touch-sensitive surface, and one or more sensors to detect intensity of contacts with the touch-sensitive surface. In some embodiments, the electronic device includes a display. In some embodiments, the display is a touch-screen display and the touch-sensitive surface is on or integrated with the display. In some embodiments, the display is separate from the touch-sensitive surface. Some operations in method  600  are, optionally, combined and/or the order of some operations is, optionally, changed. 
     As described below, the method  600  simplifies processing of touch inputs. The method reduces the computational burden on a software application, thereby creating a more efficient electronic device. In addition, the size of the software application is reduced, thereby occupying less storage space and memory. 
     The device detects ( 602 ) a touch input on the touch-sensitive surface (e.g., contact  504 ,  FIG.  5 B ). 
     In response to detecting the touch input on the touch-sensitive surface, the device determines ( 604 ) an intensity of the touch input (e.g., a force applied by the touch input) on the touch-sensitive surface (e.g., Intensity of Contact  504 ,  FIG.  5 B ). 
     In accordance with the intensity of the touch input on the touch-sensitive surface and one or more preselected intensity thresholds, the device determines ( 606 ) an intensity stage of the touch input. For example, contact  504  is determined to be in stage 1 in  FIG.  5 B . The intensity stage of the touch input is selected from a plurality of predefined intensity stages (e.g., stages 1, 2, and 3). In some embodiments, the plurality of predefined intensity stages includes three or more distinct intensity stages. In some embodiments, the plurality of predefined intensity stages includes three or more non-overlapping intensity stages. 
     In some embodiments, determining the intensity stage of the touch input includes comparing the intensity of the touch input with the one or more preselected intensity thresholds. In some embodiments, determining the intensity stage of the touch input depends on a previous intensity stage of the touch input. For example, if the touch input has been in stage 2, the intensity of the touch input is compared with an activation intensity threshold for stage 3 to determine whether the touch input transitions to stage 3, and with a release intensity threshold for stage 2 to determine whether the touch input transitions to stage 1. In some embodiments, the determination of the intensity stage of the touch input is performed by the contact motion module  130  ( FIG.  3 G ) (e.g., the contact intensity module  175  in the contact motion module  130 ). 
     In some embodiments, the intensity stage of the touch input is determined in accordance with the intensity of the touch input on the touch-sensitive surface, the one or more predefined intensity thresholds, and time-based criteria described above. As explained above, for some “deep press” inputs, the intensity of a contact exceeding a second intensity threshold during the input, greater than the first intensity threshold for a light press, triggers a second response only if a delay time has elapsed between meeting the first intensity threshold and meeting the second intensity threshold. 
     In some embodiments, the device stores ( 608 ) a first software application (e.g., E-mail Client Module  140 ,  FIG.  3 A ). The intensity stage of the touch input is determined by a contact intensity module that is distinct and separate from the first software application (e.g., a firmware embedded in a touch-sensitive input device, such as a trackpad, that include the touch-sensitive surface, an operating system, etc.). For example, in  FIG.  3 G , contact intensity module  175  in contact/motion module  130  sends touch information  472 , which in some embodiments include intensity stage  478 , to application  136 . 
     In some embodiments, the device sends ( 610 ) to the first software application from the contact intensity module touch information that identifies the intensity stage of the touch input (e.g., in  FIG.  3 G , touch information  472  including intensity stage  478  is sent from contact intensity module  175  to application  136 ). 
     In some embodiments, the device sends ( 612 ,  FIG.  6 B ) information from the contact intensity module, the information indicating that the intensity of the touch input is available to the first software application (e.g., availability information  474 ,  FIG.  3 G ). 
     In some embodiments, the device repeats ( 614 ) the operations of determining an intensity of the touch input, determining an intensity stage of the touch input, and sends touch information while the touch input is detected on the touch-sensitive surface. In some embodiments, the operations are repeated at a predefined interval (or a predefined frequency). For example, the device repeats such operations while a contact remains on the touch-sensitive surface. 
     In some embodiments, the device determines ( 616 ) one or more intensity-based progress values of the touch input based on an intensity range associated with the determined intensity stage; and sends touch information to the first software application (e.g., touch information  472  in  FIG.  3 G ). The touch information includes the one or more intensity-based progress values of the touch input (e.g., stage progress value  482  and transition progress value  484 ) and information identifying the intensity stage of the touch input (e.g., intensity stage  478 ). 
     In some embodiments, the one or more intensity-based progress values of the touch input include ( 618 ) a transition progress value of the touch input (e.g., transition progress value  484 ,  FIG.  3 G ). In some embodiments, the transition progress value indicates a normalized intensity required for a transition to an intensity stage that is adjacent to the determined intensity stage. 
     In some embodiments, the one or more intensity-based progress values of the touch input include ( 620 ) a stage progress value of the touch input (e.g., stage progress value  482 ,  FIG.  3 G ). In some embodiments, the stage progress value indicates a normalized intensity that is based on the intensity of the touch input and predefined intensity thresholds for the determined intensity stage. 
     In some embodiments, in response to detecting the touch input, the device determines ( 622 ) a first intensity applied by the touch input on the touch-sensitive surface (e.g., intensity of contact  504  in  FIG.  5 C ). In accordance with a determination that the first intensity applied by the touch input on the touch-sensitive surface does not satisfy a stage activation intensity threshold for a second intensity stage, the device determines that the touch input is in a first intensity stage that is distinct from the second intensity stage (e.g., in  FIG.  5 C , contact  504  remains in stage 1). In some embodiments, the second intensity stage is adjacent to the first intensity stage. In some embodiments, the method includes sending first touch information that identifies the first intensity stage of the touch input to the first software application. Subsequent to determining that the touch input is in the first intensity stage, the device determines a second intensity applied by the touch input on the touch-sensitive surface (e.g., intensity of contact  504  in  FIG.  5 D ). The second intensity is distinct from the first intensity. In some embodiments, the device determines that an intensity applied by the touch input on the touch-sensitive surface has changed from the first intensity to the second intensity. In accordance with a determination that the second intensity applied by the touch input on the touch-sensitive surface satisfies the stage activation intensity threshold for the second intensity stage (e.g., intensity of contact  504  is above “IT 2 ” in  FIG.  5 D ), the device determines that the touch input is in the second intensity stage (e.g., in  FIG.  5 D , contact  504  is in stage 2). 
     In some embodiments, subsequent to determining that the touch input is in the second intensity stage, the device determines ( 624 ,  FIG.  6 C ) a third intensity applied by the touch input on the touch-sensitive surface (e.g., intensity of contact  504  in  FIG.  5 F ). The third intensity is distinct from the second intensity. In accordance with a determination that the third intensity does not satisfy a stage release intensity threshold for the second intensity stage (e.g., intensity of contact  504  is above “IT 2R ” in  FIG.  5 F ), distinct from the stage activation intensity threshold for the second intensity stage (e.g., “IT 2 ” in  FIG.  5 F ), the device determines that the touch input remains in the second intensity stage (e.g., contact  504  remains in stage 2 in  FIG.  5 F ). Subsequent to determining that the touch input remains in the second intensity stage, the device determines a fourth intensity applied by the touch input on the touch-sensitive surface (e.g., intensity of contact  504  in  FIG.  5 G ). The fourth intensity is distinct from the third intensity. In accordance with a determination that the fourth intensity satisfies the stage release intensity threshold for the second intensity stage (e.g., “IT 2R ” in  FIG.  5 F ), the device determines that the touch input is in the first intensity stage (e.g., contact  504  is in stage 1 in  FIG.  5 G ). 
     In some embodiments, subsequent to determining that the touch input remains in the second intensity stage, the device determines ( 626 ) a third intensity applied by the touch input on the touch-sensitive surface (e.g., intensity of contact  504  in  FIG.  5 I ). The third intensity is distinct from the second intensity. In accordance with a determination that the third intensity satisfies a stage activation threshold for the third intensity stage (e.g., “IT 3 ” in  FIG.  5 I ), distinct from the stage activation intensity threshold for the second intensity stage, the device determines that the touch input is in the third intensity stage (e.g., contact  504  is in stage 3 in  FIG.  5 I ). 
     In some embodiments, subsequent to determining that the touch input is in the third intensity stage, the device determines ( 628 ) a fourth intensity applied by the touch input on the touch-sensitive surface (e.g., intensity of contact  504  in  FIG.  5 F ). The fourth intensity is distinct from the third intensity. In accordance with a determination that the fourth intensity satisfies a stage release intensity threshold for the third intensity stage (e.g., intensity of contact  504  is below “IT 3R ” in  FIG.  5 F ), distinct from the stage activation threshold for the third intensity stage, the device determines that the touch input is in the second intensity stage. 
     In some embodiments, the device identifies ( 630 ,  FIG.  6 A ) an intensity model identifier from a plurality of predefined intensity model identifiers (e.g., exemplary intensity models and corresponding intensity model identifiers described in Appendix A). The intensity stage of the touch input is selected from a plurality of intensity stages that correspond to the identified intensity model identifier. 
     The device processes ( 632 ) the touch input based on the intensity stage of the touch input (e.g., generates a tactile output). 
     It should be understood that the particular order in which the operations in  FIGS.  6 A- 6 C  have been described is merely exemplary and is not intended to indicate that the described order is the only order in which the operations could be performed. One of ordinary skill in the art would recognize various ways to reorder the operations described herein. Additionally, it should be noted that details of other processes described herein with respect to other methods described herein (e.g., methods  650 ,  700 ,  750 ,  800 ,  900 ,  1000 ,  1100 , and  1200 ) are also applicable in an analogous manner to method  600  described above with respect to  FIGS.  6 A- 6 C . For example, the touch input processing described above with reference to method  600  optionally have one or more of the characteristics of the touch input processing based on a touch characterization parameter described herein with reference to other methods described herein (e.g., methods  650 ,  700 ,  750 ,  800 ,  900 ,  1000 ,  1100 , and  1200 ). For brevity, these details are not repeated here. 
     In addition, one of ordinary skill in the art would recognize that many modifications and variations are possible in view of the above teachings. 
     For example, in accordance with some embodiments, a method is performed at an electronic device with a touch-sensitive surface. The electronic device includes one or more sensors to detect intensity of contacts with the touch-sensitive surface (e.g., the touch-sensitive surface includes one or more sensors to detect the intensity of contacts with the touch-sensitive surface). In some embodiments, the touch-sensitive surface is integrated with a display. In some embodiments, the touch-sensitive surface is separate from the display. The method includes, in response detecting the touch input on the touch-sensitive surface, determining an intensity of the touch input on the touch-sensitive surface; and, in accordance with the intensity of the touch input on the touch-sensitive surface and one or more preselected intensity thresholds, a transition progress value of the touch input. The method also includes processing the touch input based on the transition progress value of the touch input. 
     For another example, in accordance with some embodiments, a method is performed at an electronic device with a touch-sensitive surface. The electronic device includes one or more sensors to detect intensity of contacts with the touch-sensitive surface (e.g., the touch-sensitive surface includes one or more sensors to detect the intensity of contacts with the touch-sensitive surface). In some embodiments, the touch-sensitive surface is integrated with a display. In some embodiments, the touch-sensitive surface is separate from the display. The method includes, in response detecting the touch input on the touch-sensitive surface, determining an intensity of the touch input on the touch-sensitive surface; and, in accordance with the intensity of the touch input on the touch-sensitive surface and one or more preselected intensity thresholds, a stage progress value of the touch input. The method also includes processing the touch input based on the stage progress value of the touch input. 
       FIG.  6 D  illustrate a flow diagram of a method  650  of updating a user interface based on an intensity stage of a touch input in accordance with some embodiments. The method  650  is performed at an electronic device (e.g., device  300 ,  FIG.  3 A or  3 B , or portable multifunction device  100 ,  FIG.  1 A ) with a display, a touch-sensitive surface, and one or more sensors to detect intensity of contacts with the touch-sensitive surface. In some embodiments, the display is a touch-screen display and the touch-sensitive surface is on or integrated with the display. In some embodiments, the display is separate from the touch-sensitive surface. Some operations in method  650  are, optionally, combined and/or the order of some operations is, optionally, changed. 
     The device displays ( 652 ) a user interface on the display (e.g., a user interface of an email application is displayed in  FIG.  5 A ). 
     While displaying the user interface, the device receives ( 654 ) at the first software application from a contact intensity module distinct from the first software application touch information that identifies an intensity stage of a touch input detected on the touch-sensitive surface (e.g., application  136  receives touch information  472  from contact intensity module  175 ). 
     The device updates ( 656 ) the user interface in accordance with at least the intensity stage of the touch input (e.g., an animation is shown in  FIG.  5 B ). 
     In some embodiments, the device displays ( 658 ) an animation, corresponding to a transition to or from a predefined intensity state of the touch input, the animation corresponding to an intensity-based progress value of the touch input. For example, the animation illustrated in  FIGS.  5 A- 5 D  corresponds to a stage progress value of contact  504 . In some embodiments, the touch information received at the first software application from the contact intensity module also identifies the intensity-based progress value of the touch input. 
     It should be understood that the particular order in which the operations in  FIG.  6 D  have been described is merely exemplary and is not intended to indicate that the described order is the only order in which the operations could be performed. One of ordinary skill in the art would recognize various ways to reorder the operations described herein. Additionally, it should be noted that details of other processes described herein with respect to other methods described herein (e.g., methods  600 ,  700 ,  750 ,  800 ,  900 ,  1000 ,  1100 , and  1200 ) are also applicable in an analogous manner to method  650  described above with respect to  FIG.  6 D . For example, the intensity stage described above with reference to method  650  optionally have one or more of the characteristics of the intensity stage described herein with reference to other methods described herein (e.g., methods  600 ,  700 ,  800 ,  900 ,  1000 ,  1100 , and  1200 ). For brevity, these details are not repeated here. 
       FIGS.  7 A- 7 C  illustrate a flow diagram of a method  700  of processing touch inputs based on intensity model identifiers in accordance with some embodiments. The method  700  is performed at an electronic device (e.g., device  300 ,  FIG.  3 A or  3 B , or portable multifunction device  100 ,  FIG.  1 A ) with a touch-sensitive surface, and one or more sensors to detect intensity of contacts with the touch-sensitive surface. The electronic device stores a first software application. In some embodiments, the electronic device includes a display. In some embodiments, the display is a touch-screen display and the touch-sensitive surface is on or integrated with the display. In some embodiments, the display is separate from the touch-sensitive surface. Some operations in method  700  are, optionally, combined and/or the order of some operations is, optionally, changed. 
     As described below, the method  700  simplifies processing of touch inputs. The method reduces the computational burden on a software application, thereby creating a more efficient electronic device. In addition, the size of the software application is reduced, thereby occupying less storage space and memory. 
     The device detects ( 702 ) a first touch input on the touch-sensitive surface (e.g., contact  504  in  FIG.  5 A ). 
     In response to detecting the first touch input on the touch-sensitive surface, the device determines ( 704 ) a first intensity applied by the first touch input on the touch-sensitive surface (e.g., intensity of contact  504  in  FIG.  5 A ). 
     The device identifies ( 706 ) a first intensity model identifier from a plurality of predefined intensity model identifiers. 
     In some embodiments, identifying the first intensity model identifier includes ( 708 ) identifying the first software application as corresponding to the touch input and identifying an intensity model identifier registered by (or for or corresponding to) the first software application as the first intensity model identifier. For example, the device may identify use info  458  in intensity models  454  ( FIG.  3 G ) and identify an intensity model identifier registered by the first software application. 
     In some embodiments, in response to detecting the first touch input on the touch-sensitive surface, the device generates ( 710 ) a tactile output in accordance with the intensity applied by the first touch input on the touch-sensitive surface and the one or more thresholds associated with the first intensity model identifier (e.g., a tactile output is generated when intensity of a contact crosses one of the intensity thresholds). In some embodiments, a tactile output can be generated by either the contact intensity module or the first software application (e.g., the contact intensity and/or the first software application may send instructions to one or more tactile output generators to initiate the generation of a tactile output). 
     In accordance with the first intensity applied by the first touch input on the touch-sensitive surface and one or more thresholds associated with the first intensity model identifier, the device determines ( 712 ) a first touch characterization parameter (e.g., intensity stage, transition progress or stage progress). In some embodiments, the intensity thresholds are adjusted based on historical user actions. For example, if a user repeatedly applying high intensity that exceeds certain criteria, intensity thresholds are increased for the user. 
     In some embodiments, the device selects ( 714 ) a set of thresholds (e.g., intensity thresholds), from a plurality of sets of thresholds, in accordance with the identified intensity model identifier, and determines the touch characterization parameter in accordance with the selected set of thresholds. For example, the touch characterization parameter may be determined using the set of thresholds (e.g., associated with a first intensity model identifier) shown in  FIG.  5 J  or the set of thresholds (e.g., associated with a second intensity model identifier) shown in  FIG.  5 K . 
     In some embodiments, the device identifies ( 716 ) one or more (or alternatively two or more) intensity ranges in accordance with the identified intensity model identifier, and determines a touch characterization parameter in accordance with the one or more identified intensity ranges. For example, intensity ranges may be used instead of, or in addition to, using intensity thresholds to determine one or more touch characterization parameters. 
     Subsequent to determining the first touch characterization parameter, the device sends ( 718 ,  FIG.  7 B ) first touch information to the first software application. The first touch information includes the first intensity model identifier and the first touch characterization parameter (e.g., in  FIG.  3 G , touch information  472  includes intensity model identifier  485  and characterization parameters  476 ). 
     In some embodiments, sends ( 720 ) a stream of intensity events to the first software application, each intensity event corresponding to an intensity applied by the touch input at a corresponding time. 
     In some embodiments, the device receives ( 722 ) one or more instructions from the first software application to generate a tactile output (e.g., tactile output trigger  494 ,  FIG.  3 G ). In response to receiving the one or more instructions from the software application, the device generates the tactile output in accordance with the one or more instructions from the software application. 
     In some embodiments, while continuing to detect the first touch input on the touch-sensitive surface, the device receives ( 724 ) one or more instructions to use an intensity model that corresponds to a second intensity model identifier that is distinct from the first intensity model identifier (e.g., from the first software application). For example, in  FIG.  3 G , application  136  sends intensity model identifier  490  to be used by contact intensity module  175  for a specified range of locations (e.g., tracking region  492 ) on the display. Subsequent to receiving the one or more instructions to use the intensity model that corresponds to the second intensity model identifier, the device determines a second intensity applied by the first touch input on the touch-sensitive surface, and processes the first touch input based on the second intensity model identifier. For example, in  FIG.  5 S , icon  510 - 1  and email icon  546 - 1  are associated with distinct intensity models, and the first touch input, once moved on the touch-sensitive surface to a location that corresponds to email icon  546 - 1 , is processed based on an intensity model associated with email icon  546 , such as a second intensity model). In some embodiments or in some circumstances, the first intensity and the second intensity are identical. Even though the first intensity and the second intensity are identical, the device may respond differently based on the intensity thresholds in the intensity models. In some embodiments or some circumstances, the second intensity and the first intensity are distinct. 
     In some embodiments, the device determines that the first touch input has ceased to be detected on the touch-sensitive surface (e.g., a complete lift-off of the first touch input or reduced intensity below a detection threshold), and detects a subsequent touch input. The device identifies a second intensity model identifier based on a location of the subsequent touch input (e.g., a location on touch-sensitive surface  451  or a corresponding location on display  450 ). 
     In some embodiments, while continuing to detect the first touch input on the touch-sensitive surface, subsequent to processing the first touch input based on the second intensity model identifier, the device receives ( 726 ,  FIG.  7 C ) one or more instructions to use an intensity model that corresponds to a third intensity model identifier that is distinct from the first intensity model identifier and the second intensity model identifier (e.g., from the first software application). Subsequent to receiving the one or more instructions to use the intensity model that corresponds to the third intensity model identifier, the device determines a third intensity applied by the first touch input on the touch-sensitive surface; and processes the first touch input based on the third intensity model identifier. In some embodiments, the third intensity corresponds to the second intensity. In some embodiments, the third intensity and the second intensity are identical. 
     In some embodiments, the device determines ( 728 ) that the first touch input has ceased to be detected on the touch-sensitive surface. Subsequent to determining that the first touch input has ceased to be detected on the touch-sensitive surface, the device detects a second touch input on the touch-sensitive surface that is separate from the first touch input, and processes the second touch input based on the first intensity model identifier. For example, as shown in  FIG.  5 L- 5 N , the second intensity model expires (e.g., the device switches back to the first intensity model) upon the lift-off of the first touch input. In some embodiments, the device selects the first intensity model identifier based on a location of the second touch input. 
     In some embodiments, processing the touch input based on the second intensity model identifier includes ( 730 ), in accordance with the second intensity applied by the touch input on the touch-sensitive surface and one or more thresholds associated with the second intensity model identifier, determining a second touch characterization parameter (e.g., intensity stage, stage progress value, and/or transition progress value in  FIG.  5 J ). The second touch characterization parameter is distinct from the first touch characterization parameter. For example, the touch characterization parameter (e.g., stage, transition progress, stage progress, etc.) has changed because the intensity model identifier (and the corresponding intensity model) has changed regardless of whether the intensity of the touch input has changed. Processing the touch input also includes, subsequent to determining the second touch characterization parameter, sending second touch information to the first software application. The second touch information includes the second intensity model identifier and the second touch characterization parameter. 
     In some embodiments, processing the touch input based on the second intensity model identifier includes ( 732 ) foregoing generation of a tactile output in accordance with the second intensity failing to satisfying the one or more thresholds associated with the second intensity model identifier. The electronic device (e.g., the touch-sensitive surface of the electronic device) is configured to generate a tactile output in accordance with the second intensity satisfying at least one of the one or more thresholds associated with the first intensity model identifier. For example, as shown in  FIG.  5 L , when intensity of contact  504  decreases below a previous release intensity threshold IT 1R  but remains above a current release intensity threshold IT 1R-2 , the device foregoes generating a tactile output even though the device would have generated a tactile output if the previous release intensity threshold IT 1R  were used. 
     In some embodiments, subsequent to detecting the first touch input, the device receives ( 734 ,  FIG.  7 B ) one or more instructions to use an intensity model that corresponds to a second intensity model identifier that is distinct from the first intensity model identifier (e.g., from the first software application). Subsequent to receiving the one or more instructions to use the intensity model that corresponds to the second intensity model identifier, the device detects a second touch input on the touch-sensitive surface; and, in response to detecting the second touch input on the touch-sensitive surface, determines a second intensity applied by the second touch input on the touch-sensitive surface. The device also processes the second touch input based on the second intensity model identifier. 
     It should be understood that the particular order in which the operations in  FIGS.  7 A- 7 C  have been described is merely exemplary and is not intended to indicate that the described order is the only order in which the operations could be performed. One of ordinary skill in the art would recognize various ways to reorder the operations described herein. Additionally, it should be noted that details of other processes described herein with respect to other methods described herein (e.g., methods  600 ,  650 ,  750 ,  800 ,  900 ,  1000 ,  1100 , and  1200 ) are also applicable in an analogous manner to method  700  described above with respect to  FIGS.  7 A- 7 C . For example, the touch characterization parameter described above with reference to method  700  optionally have one or more of the characteristics of the intensity stage described herein with reference to other methods described herein (e.g., method  600 ,  650 ,  750 ,  800 ,  900 ,  1000 ,  1100 , and  1200 ). For brevity, these details are not repeated here. 
     In addition, one of ordinary skill in the art would recognize that many modifications and variations are possible in view of the above teachings. 
     For example, in accordance with some embodiments, a method is performed at an electronic device with a touch-sensitive surface. The electronic device includes one or more sensors to detect intensity of contacts with the touch-sensitive surface (e.g., the touch-sensitive surface includes one or more sensors to detect the intensity of contacts with the touch-sensitive surface) and the electronic device stores a first software application. In some embodiments, the touch-sensitive surface is integrated with a display. In some embodiments, the touch-sensitive surface is separate from the display. The method is performed using instructions other than instructions in the first software application (e.g., using a contact intensity module). The method includes detecting a touch input on a touch-sensitive surface; and, in response to detecting the touch input on the touch-sensitive surface, determining an intensity applied by the touch input on the touch-sensitive surface. The method also includes selecting a set of thresholds, from a plurality of sets of thresholds, for the touch input. At least one set of thresholds of the plurality of sets of thresholds includes multiple thresholds. The method further includes determining a touch characterization parameter of the touch input in accordance with the selected set of thresholds; and sending touch information to the first software application. The touch information includes the touch characterization parameter. 
     In some embodiments, the set of thresholds is selected based on a behavior identifier. 
     In some embodiments, the set of thresholds is selected based on a location of the touch input. In some embodiments, the behavior identifier is selected based on the location of the touch input. 
     In accordance with some embodiments, a method is performed at an electronic device with a touch-sensitive surface. The electronic device includes one or more sensors to detect intensity of contacts with the touch-sensitive surface (e.g., the touch-sensitive surface includes one or more sensors to detect the intensity of contacts with the touch-sensitive surface) and the electronic device stores a first software application. In some embodiments, the touch-sensitive surface is integrated with a display. In some embodiments, the touch-sensitive surface is separate from the display. The method is performed using instructions other than instructions in the first software application (e.g., using a contact intensity module). The method includes detecting a touch input on a touch-sensitive surface; and, in response to detecting the touch input on the touch-sensitive surface, determining an intensity applied by the touch input on the touch-sensitive surface. The method also includes selecting a set of intensity ranges, from a plurality of sets of intensity ranges, for the touch input. In some embodiments, at least one set of intensity ranges of the plurality of sets of intensity ranges includes multiple intensity ranges. The method further includes determining a touch characterization parameter of the touch input in accordance with the selected set of intensity ranges; and sending touch information to the first software application. The touch information includes the touch characterization parameter. 
       FIG.  7 D  illustrate a flow diagram of a method  750  of updating a user interface based on a touch characterization parameter in accordance with some embodiments. The method  750  is performed at an electronic device (e.g., device  300 ,  FIG.  3 A or  3 B , or portable multifunction device  100 ,  FIG.  1 A ) with a display, a touch-sensitive surface, and one or more sensors to detect intensity of contacts with the touch-sensitive surface. In some embodiments, the display is a touch-screen display and the touch-sensitive surface is on or integrated with the display. In some embodiments, the display is separate from the touch-sensitive surface. Some operations in method  750  are, optionally, combined and/or the order of some operations is, optionally, changed. 
     The device displays ( 752 ) a user interface of the first software application. 
     The device registers ( 754 ) a first intensity model identifier of a plurality of predefined force model identifiers. 
     In some embodiments, the device registers ( 756 ) a second intensity model identifier of the plurality of predefined force model identifiers. The first intensity model identifier is registered with respect to a first region of the user interface of the first software application and the second intensity model identifier is registered with respect to a second region, of the user interface of the first software application, that is distinct from the first region of the user interface of the first software application. In some embodiments, the first and second regions can be overlapping, but still distinct. 
     In some embodiments, the device concurrently displays ( 758 ) a user interface of a second software application while displaying the user interface of the first software application, and registers a third intensity model identifier of the plurality of predefined force model identifiers. The third intensity model identifier is registered with respect to a region, of the user interface of the second software application, that is distinct from the first region of the user interface of the first software application. 
     Subsequent to the registering, the device receives ( 760 ) touch information that includes the first intensity model identifier and a touch characterization parameter; and, in response to receiving the touch information, the device updates ( 762 ) a user interface of the first software application in accordance with the touch characterization parameter. 
     It should be understood that the particular order in which the operations in  FIG.  7 D  have been described is merely exemplary and is not intended to indicate that the described order is the only order in which the operations could be performed. One of ordinary skill in the art would recognize various ways to reorder the operations described herein. Additionally, it should be noted that details of other processes described herein with respect to other methods described herein (e.g., methods  600 ,  650 ,  700 ,  800 ,  900 ,  1000 ,  1100 , and  1200 ) are also applicable in an analogous manner to method  750  described above with respect to  FIG.  7 D . For example, the touch characterization parameter described above with reference to method  750  optionally have one or more of the characteristics of the touch characterization parameter described herein with reference to other methods described herein (e.g., methods  600 ,  650 ,  700 ,  800 ,  900 ,  1000 ,  1100 , and  1200 ). For brevity, these details are not repeated here. 
     In addition, one of ordinary skill in the art would recognize that many modifications and variations are possible in view of the above teachings. 
     For example, in accordance with some embodiments, a method is performed at an electronic device with a touch-sensitive surface. The electronic device includes one or more sensors to detect intensity of contacts with the touch-sensitive surface (e.g., the touch-sensitive surface includes one or more sensors to detect the intensity of contacts with the touch-sensitive surface) and the electronic device stores a first software application. In some embodiments, the touch-sensitive surface is integrated with a display. In some embodiments, the touch-sensitive surface is separate from the display. The method includes registering first and second intensity model identifiers of a plurality of predefined intensity model identifiers; and, subsequent to the registering, receiving touch information that includes a respective intensity model identifier and a touch characterization parameter. The respective intensity model identifier is the first intensity model identifier or the second intensity model identifier. The method also includes updating a user interface of the first software application in accordance with the touch characterization parameter and the respective force model identifier. 
       FIGS.  8 A- 8 C  illustrate a flow diagram of a method  800  of processing touch inputs in different regions based on distinct intensity models in accordance with some embodiments. The method  800  is performed at an electronic device (e.g., device  300 ,  FIG.  3 A or  3 B , or portable multifunction device  100 ,  FIG.  1 A ) with a touch-sensitive surface and one or more sensors to detect intensity of contacts with the touch-sensitive surface. In some embodiments, the device stores a first software application. In some embodiments, the device includes a display. In some embodiments, the display is a touch-screen display and the touch-sensitive surface is on or integrated with the display. In some embodiments, the display is separate from the touch-sensitive surface. Some operations in method  800  are, optionally, combined and/or the order of some operations is, optionally, changed. 
     As described below, the method  800  simplifies processing of touch inputs. The method reduces the computational burden on a software application, thereby creating a more efficient electronic device. In addition, the size of the software application is reduced, thereby occupying less storage space and memory. 
     In some embodiments, prior to detecting a first touch input, the device displays ( 802 ) a user interface that includes a first display region and a second display region (e.g., a user interface of a first software application and a user interface of a second software application, as shown in  FIG.  5 T ). The first display region corresponds to a first touch region of the touch-sensitive surface and the second display region corresponds to a second touch region of the touch-sensitive surface (e.g., in  FIG.  5 T , the user interface of the first software application corresponds to location  502 -A on touch-sensitive surface  451  and the user interface of the second software application corresponds to location  502 -B on touch-sensitive surface  451 ). 
     In some embodiments, the first display region corresponds ( 804 ) to a user interface of the first software application and the second display region corresponds to a user interface of a second software application (e.g., as shown in  FIG.  5 T ). In some embodiments, both the first display region and the second display region correspond to the first software application (e.g., icon  510 - 1  and email icon  546 - 7  in  FIG.  5 S ). 
     The device detects ( 806 ) a first touch input on a first touch region of the touch-sensitive surface (e.g., contact  522  in  FIG.  5 V ). 
     The device identifies ( 808 ) a first intensity model identifier, associated with the first touch region of the touch-sensitive surface, from a plurality of predefined intensity model identifiers (e.g., an intensity model identifier that corresponds an intensity model with intensity thresholds IT 1 , IT 2 , and IT 3 , etc. as shown in  FIG.  5 W ). 
     In response to detecting the first touch input on the first touch region of the touch-sensitive surface, the device determines ( 810 ) a first intensity applied by the first touch input on the first touch region of the touch-sensitive surface (e.g., intensity of contact  522  in  FIG.  5 W ). 
     In accordance with the first intensity applied by the first touch input on the touch-sensitive surface and one or more thresholds associated with the first intensity model identifier, the device determines ( 812 ) a first touch characterization parameter (e.g., stage, transition progress or stage progress). 
     Subsequent to determining the first touch characterization parameter, the device sends ( 814 ) first touch information to the first software application (e.g., touch information  472  is sent from contact motion module  130  in  FIG.  3 G ). The first touch information includes the first touch characterization parameter. 
     The device detects ( 816 ,  FIG.  8 B ) a second touch input on a second touch region of the touch-sensitive surface (e.g., contact  524  in  FIG.  5 Y ). The second touch region of the touch-sensitive surface is distinct from the first touch region of the touch-sensitive surface. 
     The device identifies ( 818 ) a second intensity model identifier, associated with the second touch region of the touch-sensitive surface, from the plurality of predefined intensity model identifiers (e.g., an intensity model identifier that corresponds an intensity model with intensity thresholds IT 1  and IT 1R , as shown in  FIG.  5 Y ). 
     In response to detecting the second touch input on the second touch region of the touch-sensitive surface, the device determines ( 820 ) a second intensity applied by the second touch input on the second touch region of the touch-sensitive surface (e.g., intensity of contact  524  in  FIG.  5 Z ). 
     In accordance with the second intensity applied by the second touch input on the touch-sensitive surface and one or more thresholds associated with the second intensity model identifier, the device determines ( 822 ) a second touch characterization parameter (e.g., stage, transition progress or stage progress). 
     Subsequent to determining the second touch characterization parameter, the device sends ( 824 ) second touch information to the first software application (e.g., touch information  472  is sent from contact motion module  130  in  FIG.  3 G ). The second touch information includes the second touch characterization parameter. 
     In some embodiments, in response to detecting the first touch input on the first touch region of the touch-sensitive surface, the device generates ( 826 ) a first tactile output in accordance with the first intensity applied by the first touch input on the touch-sensitive surface and the one or more thresholds associated with the first intensity model identifier (e.g., a tactile output is generated when intensity of contact  522  crosses the intensity threshold IT 1  in  FIG.  5 W ). In response to detecting the second touch input on the second touch region of the touch-sensitive surface, the device generates a second tactile output in accordance with the second intensity applied by the second touch input on the touch-sensitive surface and the one or more thresholds associated with the second intensity model identifier (e.g., a tactile output is generated when intensity of contact  524  crosses the intensity threshold IT 1  in  FIG.  5 Z ). 
     In some embodiments, at least a portion of the first touch region overlaps ( 828 ,  FIG.  8 C ) with at least a portion of the second touch region. For example, as shown in  FIG.  5 AA , the user interface of the first software application and the user interface of the second software application at least partially overlap. Thus, the corresponding touch regions also overlap at least partially. 
     In some embodiments, the device detects ( 830 ) a third touch input on an overlapping touch region, of the touch-sensitive surface, that corresponds to an overlap of the first touch region and the second touch region (e.g., contact  526  in  FIG.  5 BB ). The device selects an intensity model identifier between the first intensity model identifier and the second intensity model identifier for the overlapping touch region; and, in response to detecting the third touch input on the overlapping touch region, determines a third intensity applied by the third touch input on the overlapping touch region of the touch-sensitive surface. In accordance with the third intensity applied by the third touch input on the overlapping touch region of the touch-sensitive surface and one or more thresholds associated with the selected intensity model identifier, the device determines a third touch characterization parameter (e.g., stage, transition progress or stage progress). Subsequent to determining the third touch characterization parameter, the device sends third touch information to the first software application. The third touch information includes the third touch characterization parameter. For example, if a first intensity model (associated with the first software application) is selected, intensity of contact  526  is processed based on the first intensity model (e.g.,  FIG.  5 BB ). If a second intensity model (associated with the second software application) is selected, intensity of contact  526  is processed based on the second intensity model (e.g.,  FIG.  5 CC ). 
     In some embodiments, both the first intensity model identifier and the second intensity model identifier are associated ( 832 ) with priorities applicable to the overlapping touch region, and the intensity model identifier is selected based on the priority of the first intensity model identifier and the priority of the second intensity model identifier for the overlapping touch region (e.g., priority  489  of each respective intensity model  456 - 1 ,  456 - 2 , and  456 - 3  in  FIG.  3 G ). In some embodiments, the priority of an intensity model is explicitly assigned (e.g., the priority is stored in a dedicated data field, such as priority  489  in  FIG.  3 G ). In some embodiments, the priority of an intensity model is indicated by its position within a list or group of intensity models (e.g., an intensity model positioned first in intensity models  454  in  FIG.  3 G  has a higher priority than an intensity model positioned second in intensity models  454 ). 
     In some embodiments, the device foregoes ( 834 ) determination of a touch characterization parameter in accordance with the third intensity and one or more thresholds associated with an intensity model identifier that has not been selected between the first intensity model identifier and the second intensity model identifier. For example, in  FIG.  5 CC , a touch characterization parameter is determined in accordance with the first intensity model, and the device foregoes determination of a touch characterization parameter in accordance with the second intensity model. 
     In some embodiments, the first intensity model identifier has been selected ( 836 ) for the overlapping region. Subsequent to detecting the third touch input, the device detects a fourth touch input on the overlapping region of the touch-sensitive surface (e.g., contact  528 ,  FIG.  5 DD ). The device selects the second intensity model identifier for the overlapping touch region (e.g., based on one or more instructions from a software application). In response to detecting the fourth touch input on the overlapping touch region, the device determines a fourth intensity applied by the fourth touch input on the overlapping touch region of the touch-sensitive surface. In accordance with the fourth intensity applied by the fourth touch input on the overlapping touch region of the touch-sensitive surface and the one or more thresholds associated with the second intensity model identifier, the device determines a fourth touch characterization parameter (e.g., an intensity stage, a stage progression value, and/or a transition progress value of contact  528  in  FIG.  5 EE ). Subsequent to determining the touch characterization parameter, the device sends fourth touch information to the first software application. The fourth touch information includes the fourth touch characterization parameter. 
     It should be understood that the particular order in which the operations in  FIGS.  8 A- 8 C  have been described is merely exemplary and is not intended to indicate that the described order is the only order in which the operations could be performed. One of ordinary skill in the art would recognize various ways to reorder the operations described herein. Additionally, it should be noted that details of other processes described herein with respect to other methods described herein (e.g., methods  600 ,  650 ,  700 ,  750 ,  900 ,  1000 ,  1100 , and  1200 ) are also applicable in an analogous manner to method  800  described above with respect to  FIGS.  8 A- 8 C . For example, the touch characterization parameter described above with reference to method  800  optionally have one or more of the characteristics of the touch characterization parameter described herein with reference to other methods described herein (e.g., methods  600 ,  650 ,  700 ,  750 ,  900 ,  1000 ,  1100 , and  1200 ). For brevity, these details are not repeated here. 
     In addition, one of ordinary skill in the art would recognize that many modifications and variations are possible in view of the above teachings. 
     For example, in some embodiments, a method is performed at an electronic device with a touch-sensitive surface. The electronic device includes one or more sensors to detect intensity of contacts with the touch-sensitive surface (e.g., the touch-sensitive surface includes one or more sensors to detect the intensity of contacts with the touch-sensitive surface) and the electronic device stores a first software application. In some embodiments, the touch-sensitive surface is integrated with a display. In some embodiments, the touch-sensitive surface is separate from the display. The method includes displaying a user interface that includes a first display region and a second display region that is distinct from the first display region; and, while displaying the user interface, detecting a first touch input at a location on the touch-sensitive surface that corresponds to the first display region (e.g., while a cursor is displayed over the first display region in the user interface). The method also includes, in response to detecting the first touch input at a location on the touch-sensitive surface that corresponds to the first display region, determining a first intensity applied by the first touch input on the touch-sensitive surface; in accordance with the first intensity applied by the first touch input on the touch-sensitive surface and a first set of one or more thresholds associated with the first display region, determining a first touch characterization parameter (e.g., stage, transition progress or stage progress); and, subsequent to determining the first touch characterization parameter, sending first touch information to the first software application. The first touch information includes the first touch characterization parameter. The method further includes detecting a second touch input at a location on the touch-sensitive surface that corresponds to the second display region; and, in response to detecting the second touch input at a location on the touch-sensitive surface that corresponds to the second display region, determining a second intensity applied by the second touch input on the touch-sensitive surface; in accordance with the second intensity applied by the second touch input on the touch-sensitive surface and a second set of one or more thresholds associated with the second display region, determining a second touch characterization parameter (e.g., stage, transition progress or stage progress); and, subsequent to determining the second touch characterization parameter, sending second touch information to the first software application. The second touch information includes the second touch characterization parameter. 
       FIGS.  9 A- 9 D  illustrate a flow diagram of a method  900  of processing a touch input based on a location-based intensity model in accordance with some embodiments. The method  900  is performed at an electronic device (e.g., device  300 ,  FIG.  3 A or  3 B , or portable multifunction device  100 ,  FIG.  1 A ) with a touch-sensitive surface and one or more sensors to detect intensity of contacts with the touch-sensitive surface. In some embodiments, the device includes a display. In some embodiments, the display is a touch-screen display and the touch-sensitive surface is on or integrated with the display. In some embodiments, the display is separate from the touch-sensitive surface. Some operations in method  900  are, optionally, combined and/or the order of some operations is, optionally, changed. 
     As described below, the method  900  simplifies processing of touch inputs. The method reduces the computational burden on a software application, thereby creating a more efficient electronic device. In addition, the size of the software application is reduced, thereby occupying less storage space and memory. 
     The device detects ( 902 ) a touch input on the touch-sensitive surface (e.g., contact  536  in  FIG.  5 FF  or contact  538  in  FIG.  5 HH ). 
     In response to detecting the touch input, the device, in accordance with a determination that the touch input is at a location on the touch-sensitive surface that is associated with a first intensity model of a plurality of different intensity models, processes ( 904 ) the touch input in accordance with an intensity applied by the touch input on the touch-sensitive surface and the first intensity model (e.g., without processing the touch input in accordance with the second intensity model). The device, in accordance with a determination that the touch input is at a location on the touch-sensitive surface that is associated with a second intensity model different from the first intensity model, processes ( 906 ) the touch input in accordance with an intensity applied by the touch input on the touch-sensitive surface and the second intensity model (e.g., without processing the touch input in accordance with the first intensity model). For example, in  FIG.  5 FF , in accordance with a determination that contact  536  is detected in region  542 , contact  536  is processed based on a first intensity model (without processing contact  536  based on a second intensity model associated with region  534 - 8 ). In  FIG.  5 HH , in accordance with a determination that contact  538  is detected in region  534 - 8 , contact  538  is processed based on the second intensity model (without processing contact  538  based on the first intensity model associated with region  542 ). 
     In some embodiments, the device processes ( 908 ) the touch input in accordance with an intensity applied by the touch input and the first intensity model includes providing contact intensity information to a user-interface application (e.g., a first software application) without generating a tactile output for the touch input (e.g., a stage progress value of contact  536  in  FIG.  5 FF  is provided to application  136  in  FIG.  3 G  for determining a width of a graphical element, such as a pen stroke, and a tactile output is suppressed for contacts in region  542 ). Processing the touch input in accordance with an intensity applied by the touch input and the second intensity model includes conditionally generating a tactile output for the touch input (e.g., in  FIG.  5 HH , a tactile output is generated when the intensity crosses a certain intensity threshold for region  534 - 8 ). 
     In some embodiments, during the touch input, the electronic device detects ( 910 ,  FIG.  9 B ) application of a respective intensity on the touch-sensitive surface that is attributed to the touch input. Processing the touch input in accordance with an intensity applied by the touch input on the touch-sensitive surface and the first intensity model includes providing, to a user interface application, first touch input state information that indicates that the touch input has applied the respective intensity on the touch-sensitive surface without generating a tactile output for the touch input (e.g., a stage progress value of contact  536  in  FIG.  5 FF  is provided to application  136 , as shown in  FIG.  3 G , for determining a width of a graphical element, such as a pen stroke, and a tactile output is suppressed for contacts in region  542 ). Processing the touch input in accordance with an intensity applied by the touch input on the touch-sensitive surface and the second intensity model includes providing, to a user interface application, second touch input state information that indicates that the touch input has applied the respective intensity on the touch-sensitive surface and generating a tactile output for the touch input (e.g., a stage progress value, a transition progress value of contact  538  in  FIG.  5 HH , or a discrete indication that a corresponding user interface element has been activated). 
     In some embodiments, the first touch input state information includes ( 912 ) a continuously variable representation of intensity of the touch input (e.g., a value that varies as the intensity of the touch input changes, such as a stage progress value or a transition progress value). The second touch input state information includes an indication that the intensity of the touch input is within a range of values that correspond to activation of a user interface element that corresponds to the location on the touch-sensitive surface that is associated with the second intensity model (e.g., a discrete indication that does not vary as the intensity of the touch input changes so long as the intensity of the touch input is maintained within a predefined range of intensity values, and indicates whether a button or other affordance has been selected). 
     In some embodiments, the device detects ( 914 ) a first touch input on a first touch region (e.g., a non-tactile feedback region) of the touch-sensitive surface (e.g., contact  536  in  FIG.  5 FF ). The device also identifies a first intensity model identifier, associated with the first touch region of the touch-sensitive surface, from a plurality of predefined intensity model identifiers (e.g., the first intensity model identifier corresponds to the first intensity model). In response to detecting the first touch input on the first touch region of the touch-sensitive surface, the device determines a first intensity applied by the first touch input on the first touch region of the touch-sensitive surface; and, in accordance with the first intensity applied by the first touch input on the touch-sensitive surface and the first intensity model identifier, processes the first touch input and foregoes generation of a tactile output for the first touch input (e.g., a graphical element corresponding to a movement of contact  536  is displayed in  FIG.  5 GG ). The device detects a second touch input on a second touch region (e.g., a tactile feedback region) of the touch-sensitive surface (e.g., contact  538  in  FIG.  5 HH ). The second touch region of the touch-sensitive surface is distinct from the first touch region of the touch-sensitive surface. The device identifies a second intensity model identifier, associated with the second touch region of the touch-sensitive surface, from the plurality of predefined intensity model identifiers (e.g., the second intensity model identifier corresponds to the second intensity model). In response to detecting the second touch input on the second touch region of the touch-sensitive surface, the device determines a second intensity applied by the second touch input on the second touch region of the touch-sensitive surface; and, in accordance with the second intensity applied by the second touch input on the touch-sensitive surface and the second intensity model identifier, processes the second touch input (e.g., a corresponding character is inserted into a document, as shown in  FIG.  5 HH ) and conditionally generates a tactile output for the second touch input in accordance with the second touch input and one or more model parameters associated with the second intensity model identifier (e.g., one or more model parameters in the second intensity model). 
     In some embodiments, conditionally generating the tactile output for the second touch input includes ( 916 ,  FIG.  9 C ) foregoing generation of the tactile output for the second touch input in accordance with a determination that the second touch input fails to satisfy one or more criteria corresponding to the one or more model parameters associated with the second intensity model identifier. For example, in some embodiments, a tactile output is not generated when a touch input does not cross an intensity threshold. 
     In some embodiments, the first intensity model identifier indicates ( 918 ) that no tactile output is to be generated for a touch input on the first touch region of the touch-sensitive surface. 
     In some embodiments, the electronic device stores ( 920 ) a first software application, and the first user input and the second user input are detected while the electronic device displays a user interface of the first software application (e.g., a user interface of a word processing software application as shown in  FIGS.  5 FF- 5 JJ ). 
     In some embodiments, the user interface of the first software application includes ( 922 ) a handwriting input tool region (e.g., a character input tool region) (e.g., a handwriting input tool region  540  in  FIG.  5 FF ). In some embodiments, the handwriting input tool region is distinct from the user interface of the first software application and the handwriting input tool region overlays the user interface of the first software application (e.g., a user interface of a word processing software application). In some embodiments, the handwriting input tool region is separate from the user interface of the first software application. 
     In some embodiments, the handwriting input tool region includes ( 924 ) a plurality of selection regions, and at least a respective selection region of the one or more selection regions corresponds to the second touch region (e.g., a tactile feedback region) of the touch-sensitive surface. For example, in  FIG.  5 JJ , selection region  532 - 1  corresponds to touch region  534 - 1 . In some embodiments, the one or more selection regions collectively correspond to the second touch region. 
     In some embodiments, the handwriting input tool region includes ( 926 ) a handwriting input region, and the handwriting input region corresponds to the first touch region (e.g., a potential non-tactile feedback region) of the touch-sensitive surface. For example, in  FIG.  5 FF , handwriting input region  530  corresponds to region  542 . 
     In some embodiments, in response to detecting the first touch input on the first touch region of the touch-sensitive surface, the device displays ( 928 ) one or more graphical elements (e.g., pen strokes, such as  544  in  FIG.  5 GG ) in the handwriting input region in accordance with the first touch input. 
     In some embodiments, in response to detecting the first touch input on the first touch region (e.g., a potential non-tactile feedback region} of the touch-sensitive surface, the device displays ( 930 ,  FIG.  9 D ) a plurality of groups of characters in the plurality of selection regions (e.g., characters in selection regions  532 - 5  through  532 - 8  in  FIG.  5 GG ). A respective group of characters is selected based on the one or more displayed graphical elements in the handwriting input region, and the respective group of characters is displayed in a respective selection region (e.g., characters, such as Chinese, Korean, and Japanese characters, that correspond to displayed pen strokes). In response to detecting the second user input on the second touch region of the touch-sensitive surface at a location that corresponds to the respective selection region, the device selects the respective group of characters (e.g., in  FIG.  5 HH , in response to contact  538  in region  534 - 8 , the character in a corresponding selection region  532 - 8  is selected). In some embodiments, in response to detecting the second user input on the second touch region of the touch-sensitive surface at a location that corresponds to the respective selection region and subsequent to selecting the respective group of characters, the device displays the respective group of characters in the user interface of the first software application other than the handwriting input tool region (e.g., in  FIG.  5 HH , in response to contact  538  on region  534 - 8 , the character in a corresponding selection region  532 - 8  is inserted into the document). 
     In some embodiments, processing the first touch input detected on the first touch region of the touch-sensitive surface includes ( 932 ) determining that the first touch input has satisfied a drawing intensity threshold; and, in accordance with a determination that the first touch input has exceeded the drawing intensity threshold, displaying the one or more graphical elements in the handwriting input region in accordance with the first touch input. A first terminal region of a respective graphical element of the one or more graphical elements corresponds to a location where the first touch input has been determined to satisfy the drawing intensity threshold. For example, as shown in  FIG.  5 II , drawing of a graphical element is initiated in response to intensity of contact  536  satisfying the drawing intensity threshold IT D . 
     In some embodiments, processing the first touch input detected on the first touch region of the touch-sensitive surface includes ( 934 ) while continuing to detect the first touch input on the touch-sensitive surface, continuing to update the one or more graphical elements in the handwriting input region in accordance with the first touch input regardless of whether the first touch input has ceased to satisfy the drawing intensity threshold. For example, as shown in  FIG.  5 II , once the drawing of a graphical element is initiated, the drawing continues even if intensity of contact  536  falls below the drawing intensity threshold. 
     In some embodiments, processing the first touch input detected on the first touch region of the touch-sensitive surface includes ( 936 ) detecting that the first touch input has ceased to be detected on the touch-sensitive surface and detecting that the first touch input has resumed contact with the touch-sensitive surface within a predefined time interval subsequent to the first touch input ceasing to be detected on the touch-sensitive surface. Processing the first touch input also includes, in response to the first touch input resuming contact with the touch-sensitive surface within the predefined time interval subsequent to the first touch input ceasing to be detected on the touch-sensitive surface, updating the one or more graphical elements in the handwriting input region in accordance with the first touch input. For example, as shown in  FIG.  5 JJ , even if contact  536  breaks contact with touch-sensitive surface  451  while following a path on touch-sensitive surface  451  and subsequent contact  544  continues the path, the paths of contact  536  and contact  544  are treated as a single path. 
     It should be understood that the particular order in which the operations in  FIGS.  9 A- 9 D  have been described is merely exemplary and is not intended to indicate that the described order is the only order in which the operations could be performed. One of ordinary skill in the art would recognize various ways to reorder the operations described herein. Additionally, it should be noted that details of other processes described herein with respect to other methods described herein (e.g., methods  600 ,  650 ,  700 ,  750 ,  800 ,  1000 ,  1100 , and  1200 ) are also applicable in an analogous manner to method  900  described above with respect to  FIGS.  9 A- 9 D . For example, the intensity model described above with reference to method  900  optionally have one or more of the characteristics of the intensity model described herein with reference to other methods described herein (e.g., methods  600 ,  650 ,  700 ,  750 ,  800 ,  1000 ,  1100 , and  1200 ). For brevity, these details are not repeated here. 
       FIGS.  10 A- 10 D  illustrate a flow diagram of a method  1000  of processing a touch input based on latching of the touch input in accordance with some embodiments. The method  1000  is performed at an electronic device (e.g., device  300 ,  FIG.  3 A or  3 B , or portable multifunction device  100 ,  FIG.  1 A ) with a touch-sensitive surface and one or more sensors to detect intensity of contacts with the touch-sensitive surface. The device stores a first software application. In some embodiments, the device includes a display. In some embodiments, the display is a touch-screen display and the touch-sensitive surface is on or integrated with the display. In some embodiments, the display is separate from the touch-sensitive surface. Some operations in method  1000  are, optionally, combined and/or the order of some operations is, optionally, changed. 
     As described below, the method  1000  simplifies processing of touch inputs. The method reduces the computational burden on a software application, thereby creating a more efficient electronic device. In addition, the size of the software application is reduced, thereby occupying less storage space and memory. 
     The device displays ( 1002 ) a user interface that includes two or more display regions, including a first display region and a second display region (e.g., icon  510 - 1  and email icon  546 - 7  in  FIG.  5 KK ). 
     While displaying the user interface, the device detects ( 1004 ) a first intensity applied by a touch input at a first location on the touch-sensitive surface that corresponds to the first display region (e.g., intensity of contact  548  in  FIG.  5 LL ). 
     In some embodiments, in response to detecting the first intensity applied by the touch input, the device processes ( 1006 ) the first intensity in accordance with the one or more intensity thresholds associated with the first display region (e.g., in  FIG.  5 LL , intensity of contact  548  is processed in accordance with intensity thresholds associated with icon  510 - 1 ). 
     In some embodiments, processing the first intensity in accordance with the one or more intensity thresholds associated with the first display region includes ( 1008 ) displaying an animation that corresponds to a change in intensity applied by the touch input from a prior intensity to the first intensity (e.g., from intensity, detected prior to detecting the first intensity, to the first intensity) (e.g., icon  510 - 1  is visually distinguished in  FIG.  5 MM ). For example, the device displays a pre-latch animation that indicates that the user is interacting with a particular control in the first display region such as a change in appearance of a first button in the first display region that is proximate to a focus selector. This pre-latch animation is optionally presented at a rate that is dependent on a rate of change in the intensity of the contact or magnitude of intensity of the contact so as to provide feedback to the user as to their progress toward activating the button or latching onto the button. 
     The device detects ( 1010 ) a movement of the touch input across the touch-sensitive surface from the first location on the touch-sensitive surface to a second location on the touch-sensitive surface that corresponds to the second display region (e.g., while a cursor is displayed over the first display region) (e.g., movement of contact  548  in  FIG.  5 NN ). In some embodiments, the movement of the touch input across the touch-sensitive surface from the first location on the touch-sensitive surface to the second location on the touch-sensitive surface is detected after detecting the first intensity applied by the touch input at the first location. 
     In some embodiments, in response to detecting the movement of the touch input from the first location on the touch-sensitive surface to the second location on the touch-sensitive surface, the device displays ( 1012 ) an animation that corresponds to a change in intensity applied by the touch input (e.g., from an intensity, detected prior to detecting the first intensity, to the first intensity). For example, the device displays a pre-latch animation that indicates that the user is interacting with a particular control in the second display region such as a change in appearance of a second button in the second display region that is proximate to a focus selector. This pre-latch animation is optionally presented at a rate that is independent of a rate of change in the intensity of the contact so as to catch the animation up to a current point in the pre-activation animation that corresponds to a current intensity of the contact. 
     After detecting the movement of the touch input from the first location on the touch-sensitive surface to the second location on the touch-sensitive surface, the device detects ( 1014 ) a second intensity applied by the touch input at the second location on the touch-sensitive surface (e.g., intensity of contact  548  in  FIG.  5 OO ). 
     In response to detecting the second intensity applied by the touch input at the second location on the touch-sensitive surface, the device, in accordance with a determination that the first intensity does not satisfy a first intensity threshold (e.g., a latching intensity threshold), processes ( 1016 ,  FIG.  10 B ) the second intensity in accordance with one or more intensity thresholds associated with the second display region (e.g., in  FIG.  5 PP , contact  548  is processed based on intensity thresholds associated with email icon  546 - 7 ). 
     In some embodiments, the first intensity threshold is ( 1018 ) distinct from an activation intensity threshold. In some embodiments, the device detects a touch input at a location on the touch-sensitive surface that corresponds to the first display region; and, in response to detecting the touch input, determines an intensity applied by the touch input on the touch-sensitive surface. In accordance with a determination that the intensity applied by the touch input on the touch-sensitive surface satisfies the activation intensity threshold, the device initiates activation of the first software element (e.g., sends to the first software element one or more instructions to activate the first software element). 
     In some embodiments, processing the second intensity in accordance with the one or more intensity thresholds associated with the second display region includes ( 1020 ) displaying an animation that corresponds to a change in intensity applied by the touch input on the touch-sensitive surface (e.g., from the first intensity to the second intensity). For example, the device displays a pre-activation animation corresponding to the user interface element in the second display region such as a button press animation that indicates that a button in the second display region will be activated if the intensity of the contact increases above the button-activation intensity threshold. This pre-activation animation is optionally presented at a rate that is dependent on a rate of change in the intensity of the contact or magnitude of intensity of the contact so as to provide feedback to the user as to their progress toward activating the button. 
     In some embodiments, processing the second intensity in accordance with one or more intensity thresholds associated with the second display region includes ( 1022 ) activating a second control associated with the second display region (e.g., when the contact meets activation criteria that include a criterion that is met when the contact exceeds an activation intensity threshold for the second control). 
     In response to detecting the second intensity applied by the touch input at the second location on the touch-sensitive surface, the device, in accordance with a determination that the first intensity satisfies the first intensity threshold, processes ( 1024 ) the second intensity in accordance with one or more intensity thresholds associated with the first display region (e.g., in  FIG.  5 SS , contact  548  is processed based on intensity thresholds associated with icon  510 - 1 ). 
     In some embodiments, the one or more intensity thresholds associated with the first display region are ( 1026 ,  FIG.  10 C ) different from the one or more intensity thresholds associated with the second display region (e.g., the first display region and the second display region are both associated with different intensity models). 
     In some embodiments, the one or more intensity thresholds associated with the first display region are ( 1028 ) the same as the one or more intensity thresholds associated with the second display region (e.g., the first display region and the second display region are both associated with a same intensity model). 
     In some embodiments, processing the second intensity in accordance with the one or more intensity thresholds associated with the first display region includes ( 1030 ) displaying an animation that corresponds to a change in intensity applied by the touch input on the touch-sensitive surface (e.g., from the first intensity to the second intensity). For example, the device displays a pre-activation animation corresponding to a user interface element in the first display region such as a pre-button press animation that indicates that a button in the first display region will be activated if the intensity of the contact increases above a button-activation intensity threshold. This pre-activation animation is optionally presented at a rate that is dependent on a rate of change in the intensity applied by the touch input or magnitude of the intensity applied by the touch input so as to provide feedback to the user as to their progress toward activating the button. 
     In some embodiments, processing the second intensity in accordance with one or more intensity thresholds associated with the first display region includes ( 1032 ) activating a first control associated with the first display region (e.g., when the contact meets activation criteria that include a criterion that is met when the contact exceeds an activation intensity threshold for the first control). 
     In some embodiments, the device sends ( 1034 ,  FIG.  10 B ) first touch information to the first software application in accordance with a determination that the first intensity satisfies a reporting intensity threshold that is distinct from the first intensity threshold. The first touch information includes one or more touch parameters that correspond to the first intensity. In some embodiments, the first intensity threshold requires a higher intensity than the reporting intensity threshold. In some embodiments, the method includes, in accordance with a determination that the first intensity does not satisfy the reporting intensity threshold, foregoing sending the first touch information. The device sends second touch information to the first software application in accordance with a determination that the second intensity satisfies the reporting intensity threshold. The second touch information includes one or more touch parameters that correspond to the second intensity. 
     In some embodiments, a first display region of the two or more display regions is associated ( 1036 ,  FIG.  10 D ) with a first software element of the first software application and a second display region of the two or more display regions is associated with a second software element of the second software application. 
     In some embodiments, in accordance with the determination that the first intensity does not satisfy the first intensity threshold (e.g., not latched on the first display region), the second touch information is sent ( 1038 ) to the second software element without sending the second touch information to the first software element. 
     In some embodiments, in accordance with the determination that the first intensity satisfies the first intensity threshold (e.g., latched on the first display region), the second touch information is sent ( 1040 ) to the first software element without sending the second touch information to the second software element. 
     In some embodiments, in accordance with the determination that the first intensity satisfies the reporting intensity threshold, the first touch information is sent ( 1042 ) to the first software element. In some embodiments, the first touch information is sent to the first software element without sending the first touch information to the second software element. 
     In some embodiments, in response to detecting the touch input, the device updates ( 1044 ,  FIG.  10 B ) the user interface in accordance with the first touch information using the first software application prior to the first intensity satisfying the first intensity threshold. In some embodiments, updating the user interface in accordance with the first touch information using the first software application includes displaying an animation that indicates detection of the touch input. For example, the animation may be used to inform the user as to the intensity required to achieve latching. In some embodiments, updating the user interface in accordance with the first touch information using the first software application includes displaying an animation that indicates increase and/or decrease in an intensity applied by the touch input on the touch-sensitive surface. 
     It should be understood that the particular order in which the operations in  FIGS.  10 A- 10 D  have been described is merely exemplary and is not intended to indicate that the described order is the only order in which the operations could be performed. One of ordinary skill in the art would recognize various ways to reorder the operations described herein. Additionally, it should be noted that details of other processes described herein with respect to other methods described herein (e.g., methods  600 ,  650 ,  700 ,  750 ,  800 ,  900 ,  1100 , and  1200 ) are also applicable in an analogous manner to method  1000  described above with respect to  FIGS.  10 A- 10 D . For example, the intensity thresholds described above with reference to method  1000  optionally have one or more of the characteristics of the intensity thresholds described herein with reference to other methods described herein (e.g., methods  600 ,  650 ,  700 ,  750 ,  800 ,  900 ,  1100 , and  1200 ). For brevity, these details are not repeated here. 
       FIGS.  11 A- 11 C  are flow diagrams illustrating a method  1100 , performed by an electronic device of routing tactile outputs among a plurality of input devices that are in communication with the electronic device. In some embodiments, the electronic device includes one or more of the input devices (e.g., a touch-screen display or trackpad). As described below, the method  1100  provides tactile feedback, herein called a tactile output, to the same input device as the input device from which an input was received that triggered a reaction by an application executed by the electronic device. The method enables and/or facilitates the use of multiple input devices at which tactile outputs can be generated, and enables the use of tactile feedback by a broad range of applications that can be executed by the electronic device. The method also reduces the cognitive burden on a user when performing an operation in conjunction with an application, by providing tactile feedback that facilitates efficient use of the electronic device and the application, thereby creating a more efficient human-machine interface. For battery-operated electronic devices, enabling a user to perform an operation in accordance with a selected mode of operation faster and more efficiently conserves power and increases the time between battery charges. 
     Optionally, but typically, the device displays ( 1102 ), on a display that is part of the device or in communication with the device, a user interface for the electronic device. Examples of such user interfaces being displayed by an electronic device are shown in  FIGS.  5 A- 5 S . In some embodiments, the user interface includes two of more display regions, including a first display region and a second display region. Typically, the user interface continues to be displayed throughout performance of method  1100 , although content of the user interface may change, for example in response to inputs by a user of the electronic device. Furthermore, the device is in communication with a plurality of input devices including a first input device (e.g., a first input device having a first touch-sensitive surface that includes one or more sensors to detect intensity of contacts with the first touch-sensitive surface) that is configured to generate tactile outputs in response to inputs and a second input device (e.g., a second input device having a second touch-sensitive surface that includes one or more sensors to detect intensity of contacts with the second touch-sensitive surface) that is configured to generate tactile outputs. Non-limiting examples of the first input device are a trackpad and touch-sensitive display, and non-limiting examples of the second input device are a trackpad and touch-sensitive display. 
     The device receives ( 1104 ) an indication of an input detected by a respective input device of the plurality of input devices. In some embodiments, the touch input can be a finger touch input by a person&#39;s finger, or a stylus touch input. In response to receiving the indication of the input, the device provides ( 1106 ) information describing the input to an application running on the device that enables the application to react to the input. For example, a touch event specifying the movement (if any), location, intensity, etc. of one or more contacts is provided to an application. In some embodiments, the touch event provided to the application includes a plurality of lists, such as two or more of: a list of all touches currently detected by input devices in communication with the device, a list of all touches associated with a particular view of an application, and a list of changed touches, comprising touches for which at least one parameter or aspect (e.g., location and/or intensity) has changed since a prior touch event was provided to the application. 
     The device receives ( 1108 ) a reaction to the input from the application that indicates that a tactile output is to be generated in response to the input. For example, in some circumstances, the input includes ( 1110 ) lateral movement, and the reaction of the application includes moving a graphical user interface object across a display. 
     In response to receiving the reaction to the input from the application, the device causes ( 1112 ) the generation of a respective tactile output. More specifically, in accordance with a determination ( 1114 ) that the reaction was triggered by the first input device, the respective tactile output is generated at the first input device (e.g., touch-screen display  340 ,  FIG.  3 B ) based on the reaction to the input from the application; and in accordance with a determination ( 1116 ) that the reaction was triggered by the second input device (e.g., trackpad  332 ,  FIG.  3 B ), the respective tactile output is generated at the second input device based on the reaction to the input from the application. 
     In some embodiments, in response to receiving the reaction to the input from the application, the device determines ( 1118 ) which input device of the plurality of input devices triggered the reaction from the application. For example, in the context of  FIG.  3 B , which includes both a trackpad  332  and touch-sensitive display  340 , the device determines which of the trackpad and touch-sensitive display triggered the reaction from the application. In some embodiments, that determination is made by the application. For example, in some circumstances, inputs may be received concurrently, or during overlapping time periods, from two or more input devices, and the application may make the determination as to which of the input devices triggered the reaction. Continuing with this example, the input from one of the input devices may be used by the application to select a mode of operation or select an option, while the input from another one of the input devices triggers the reaction, and it is the application that makes this determination. 
     More specifically, and consistent with what has been described above, in some embodiments, when the reaction was triggered by the first input device, the tactile output at the first input device is generated ( 1120 ) without causing generation of any tactile output at the second input device, and when the reaction was triggered by the second input device, the tactile output at the second input device is generated ( 1122 ) without causing generation of any tactile output at the first input device. 
     In some embodiments, the information describing the input includes ( 1124 ) a respective identifier for the respective device, the reaction to the input includes the respective identifier for the respective device, and determining that the reaction was triggered by the first input device includes determining ( 1126 ) that the respective identifier is an identifier for the first input device. Similarly, the determination that the reaction was triggered by the second input device includes determining ( 1128 ) that the respective identifier is an identifier for the second input device. Furthermore, in some embodiments, the respective identifier is ( 1130 ) part of an input event (e.g., a touch event) that describes the input. Thus, in such embodiments, the module(s) that initially process inputs from the input devices and that generate or cause the generation of tactile outputs, and the application that responds to such inputs, utilize distinct identifiers for each of the input devices in communication with the device. In some embodiments, this facilitates routing tactile feedback to the input device determined (e.g., see  1118 ) to have triggered the reaction from the application. 
     In some embodiments, the device is configured ( 1132 ) to cause the generation of tactile outputs at the plurality of input devices in response to changes in intensity of contacts on the input devices in accordance with one or more intensity models. For example, this is described in greater detail above with reference to methods  600 ,  700 ,  800 ,  900  and  1000 . Furthermore, in some circumstances, the respective tactile output is generated ( 1134 ) without reference to the one or more intensity models. The following is a non-limiting set of examples of such circumstances. In one example, the tactile feedback requested by an application is in response to a lateral movement of a touch input that moves one object adjacent to, near, over or partially over another object, and the tactile feedback concerns the lateral movement, but not the intensity of the contact corresponding to the touch input. Another example in a respective tactile output is generated without reference to the one or more intensity models is a movement of the touch input that results in the application adjusting the position of an object, for example “snapping” the object to a horizontal and/or vertical position defined by a grid or guide. Yet another example in a respective tactile output is generated without reference to the one or more intensity models is a movement of the touch input that violates a predefined rule or condition (e.g., a movement of the touch input that is construed by the application to be an instruction to move an object over another object, in violation of a rule), or that satisfies a predefined rule or condition (e.g., a movement of the touch input that is construed by the application to be an instruction to move an object over another object, thereby initiating or enabling an action, such as adding the object to a collection, changing a property of the moved object or the other object, etc. 
     It should be understood that the particular order in which the operations in  FIGS.  11 A- 11 C  have been described is merely exemplary and is not intended to indicate that the described order is the only order in which the operations could be performed. One of ordinary skill in the art would recognize various ways to reorder the operations described herein. Additionally, it should be noted that details of other processes described herein with respect to other methods described herein (e.g., methods  600 ,  650 ,  700 ,  750 ,  800 ,  900 ,  1000 , and  1200 ) are also applicable in an analogous manner to method  1100  described above with respect to  FIGS.  11 A- 11 C . For example, the contacts, user interface objects, tactile outputs, intensity thresholds, and focus selectors described above with reference to method  1100  optionally have one or more of the characteristics of the contacts, user interface objects, tactile outputs, intensity thresholds, and focus selectors described herein with reference to other methods described herein (e.g., methods  600 ,  650 ,  700 ,  750 ,  800 ,  900 ,  1000 , and  1200 ). For brevity, these details are not repeated here. 
       FIGS.  12 A- 12 C  are flow diagrams illustrating a method  1200 , performed by an electronic device that is in communication with one or more input devices that are configured to generate tactile outputs in response to inputs, in which the device conditionally cancels or forgoes generation of a tactile output corresponding to the reaction from the application in accordance with a determination that tactile output criteria have not been met. The tactile output criteria include a criterion (sometimes called a timing criterion or latency criterion) that is met when an input time is less than a predetermined amount of time before the output time. In some embodiments, the electronic device includes one or more of the input devices (e.g., a touch-screen display or trackpad). 
     Method  1200  enables and/or facilitates the use of complex application software for which tactile outputs can be generated, and enables the use of tactile feedback by a broad range of applications that can be executed by the electronic device. The method also reduces the cognitive burden on a user when performing an operation in conjunction with an application, by providing limiting the provision of tactile feedback to circumstances in which the tactile feedback will be intuitively meaningful, and forgoing the provision of tactile feedback in circumstances in which the tactile feedback might be confusing to the user or even mis-informative due to latency between the input that cause the application&#39;s reaction and the time at which the tactile output would be generated. 
     In a non-limiting example, the generation of a reaction to an input by an application may be delayed by connectivity issues, a stalled process executing on the same device or another device, a failed procedure call to another application or module, or any of a potentially large number of circumstances. In at least some situations, when that delay results in a time difference between the input time, at which the input was detected by a respective input device, and an output time for the reaction by the application that exceeds a predetermined amount of time, the method forgoes generation of the tactile output corresponding to the reaction from the application. 
     Method  1200  therefore facilitates efficient use of the electronic device and the application, thereby creating a more efficient human-machine interface. For battery-operated electronic devices, enabling a user to perform an operation in accordance with a selected mode of operation faster and more efficiently conserves power and increases the time between battery charges. 
     Optionally, but typically, the device displays ( 1202 ), on a display that is part of the device or in communication with the device, a user interface for the electronic device. Examples of such user interfaces being displayed by an electronic device are shown in  FIGS.  5 A- 5 S . In some embodiments, the user interface includes two of more display regions, including a first display region and a second display region. Typically, the user interface continues to be displayed throughout performance of method  1200 , although content of the user interface may change, for example in response to inputs by a user of the electronic device. Furthermore, the device is in communication with a plurality of input devices including a first input device (e.g., a first input device having a first touch-sensitive surface that includes one or more sensors to detect intensity of contacts with the first touch-sensitive surface) that is configured to generate tactile outputs in response to inputs and a second input device (e.g., a second input device having a second touch-sensitive surface that includes one or more sensors to detect intensity of contacts with the second touch-sensitive surface) that is configured to generate tactile outputs. Non-limiting examples of an input device of the one or more input devices is a trackpad or touch-sensitive display. 
     The device receives ( 1204 ) an indication of an input detected by a respective input device of the one or more of input devices. In some embodiments, the touch input can be a finger touch input by a person&#39;s finger, or a stylus touch input. In response to receiving the indication of the input, the device provides ( 1206 ) information describing the input to an application running on the device that enables the application to react to the input. For example, a touch event specifying the movement (if any), location, intensity, etc. of one or more contacts is provided to an application. In some embodiments, the touch event provided to the application includes a plurality of lists, such as two or more of: a list of all touches currently detected by input devices in communication with the device, a list of all touches associated with a particular view of an application, and a list of changed touches, comprising touches for which at least one parameter or aspect (e.g., location and/or intensity) has changed since a prior touch event was provided to the application. 
     The device receives ( 1208 ) a reaction to the input from the application that indicates that a tactile output is to be generated in response to the input. For example, in some circumstances, the input includes movement, and the reaction of the application includes moving a graphical user interface object across a display. 
     In response to receiving the reaction to the input from the application, the device performs ( 1210 ) a set of operations, including comparing ( 1212 ) an input time for the reaction to an output time for the reaction, wherein the input time for the reaction corresponds to a time at which the input was detected by the respective input device, and the output time for the reaction corresponds to a time at which a tactile output corresponding to the reaction is configured to be generated at the respective input device. Stated another way, the comparing operation compares an input time for the input detected by the respective input device to an output time for the reaction. The set of operations performed by the device also includes determining ( 1214 ) whether tactile output criteria have been met, wherein the tactile output criteria include a criterion that is met when an input time is less than a predetermined amount of time before the output time, causing generation ( 1216 ), at the respective input device, of a tactile output corresponding to the reaction from the application in accordance with a determination that the tactile output criteria have been met, and forgoing generation ( 1218 )), at the respective input device, of the tactile output corresponding to the reaction from the application in accordance with a determination that the tactile output criteria have not been met. In some embodiments, the tactile output criteria also include tactile output routing criteria to enable tactile outputs to be generated at the device that detected an input that caused the tactile output to be generated (e.g., as described in greater detail above with reference to method  1100 . 
     In some embodiments, the input time for the reaction (e.g., the input time for the input detected by the respective input device) is stored ( 1222 ) by the device in response to receiving the indication of the input from the respective input device. Thus, the device monitors input times to ensure that stale tactile outputs are not generated at the respective input device. 
     In some embodiments, the input time for the reaction (e.g., the input time for the input detected by the respective input device) is received ( 1220 ) from the application along with the reaction to the input. Thus, in these embodiments, the application monitors input times and provides input time information to the device to ensure that stale tactile outputs are not generated at the respective input device. 
     In some embodiments, the output time for the reaction is ( 1224 ) a time at which a tactile output for the reaction would be scheduled by the device. Thus, in at least some such embodiments, the output time is a computed time, in the near future, that is either the time at which the tactile output would be generated, or is a time that the tactile output is scheduled to be generated. The later times are not necessarily identical, since in some embodiments the actual tactile output generation time may not be entirely predictable or schedulable. 
     In some embodiments, the output time for the reaction is ( 1226 ) a time at which the application requested that a tactile output be generated at the respective input device. In these embodiments, the output time is determined by the time that the application posts, transfers, or otherwise communicates its request to generate a tactile output. 
     In some embodiments, the device is configured ( 1230 ) to cause the generation of tactile outputs at the plurality of input devices in response to changes in intensity of contacts on the input devices in accordance with one or more intensity models. For example, this is described in greater detail above with reference to methods  600 ,  700 ,  800 ,  900  and  1000 . Furthermore, in some circumstances, the respective tactile output is generated ( 1234 ) without reference to the one or more intensity models. A non-limiting set of examples of such circumstances are described above with respect to operation  1132  of method  1100 . 
     In some embodiments, the predetermined amount of time that is used to determine whether the tactile output criteria have been met has a first value in a normal mode of operation, and a second value, larger than the first value, in an accessibility mode of operation. In these embodiments, in the accessibility mode, a slower reaction time to user inputs is acceptable, as is slower tactile output in response to user inputs at the one or more input devices. 
     It should be understood that the particular order in which the operations in  FIGS.  12 A- 12 C  have been described is merely exemplary and is not intended to indicate that the described order is the only order in which the operations could be performed. One of ordinary skill in the art would recognize various ways to reorder the operations described herein. Additionally, it should be noted that details of other processes described herein with respect to other methods described herein (e.g., methods  600 ,  650 ,  700 ,  750 ,  800 ,  900 ,  1000 , and  1100 ) are also applicable in an analogous manner to method  1200  described above with respect to  FIGS.  12 A- 12 C . For example, the contacts, user interface objects, tactile outputs, intensity thresholds, and focus selectors described above with reference to method  1200  optionally have one or more of the characteristics of the contacts, user interface objects, tactile outputs, intensity thresholds, and focus selectors described herein with reference to other methods described herein (e.g., methods  600 ,  650 ,  700 ,  750 ,  800 ,  900 ,  1000 , and  1100 ). For brevity, these details are not repeated here. 
     The operations in the information processing methods described above are, optionally implemented by running one or more functional modules in information processing apparatus such as general purpose processors (e.g., as described above with respect to  FIGS.  1 A,  3 A, and  3 B ) or application specific chips. 
     In accordance with some embodiments,  FIG.  13    shows a functional block diagram of electronic device  1300  configured in accordance with the principles of the various described embodiments. The functional blocks of the device are, optionally, implemented by hardware, software, firmware, or a combination thereof to carry out the principles of the various described embodiments. It is understood by persons of skill in the art that the functional blocks described in  FIG.  13    are, optionally, combined or separated into sub-blocks to implement the principles of the various described embodiments. Therefore, the description herein optionally supports any possible combination or separation or further definition of the functional blocks described herein. 
     As shown in  FIG.  13   , electronic device  1300  includes touch-sensitive surface unit  1304  configured to receive contacts and one or more sensor units  1306  configured to detect intensity of contacts with the touch-sensitive surface unit  1304 . Processing unit  1308  is coupled with the touch-sensitive surface unit  1304  and the one or more sensor units  1306 . In some embodiments, electronic device  1300  includes display unit  1302  configured to display a user interface, and processing unit  1308  is coupled with display unit  1302 . In some embodiments, processing unit  1308  includes: detecting unit  1310 , determining unit  1312 , identifying unit  1314 , touch input processing unit  1316 , sending unit  1318 , and repeating unit  1320 . 
     The processing unit  1308  configured to: detect a touch input on the touch-sensitive surface unit  1304  (e.g., with the detecting unit  1310  and/or the touch-sensitive surface unit  1304 ); in response to detecting the touch input on the touch-sensitive surface unit  1304 , determine an intensity of the touch input on the touch-sensitive surface unit  1304  (e.g., with the determining unit  1312 , the touch-sensitive surface unit  1304 , and/or the sensor units  1306 ); and, in accordance with the intensity of the touch input on the touch-sensitive surface unit  1304  and one or more preselected intensity thresholds, determine an intensity stage of the touch input (e.g., with the determining unit  1312 ), wherein the intensity stage of the touch input is selected from a plurality of predefined intensity stages; and process the touch input based on the intensity stage of the touch input (e.g., with the touch input processing unit  1316 ). 
     In some embodiments, the electronic device  1300  stores a first software application, and the intensity stage of the touch input is determined by a contact intensity module that is distinct and separate from the first software application. 
     In some embodiments, the processing unit  1308  is configured to send to the first software application from the contact intensity module touch information that identifies the intensity stage of the touch input (e.g., with the sending unit  1318 ). 
     In some embodiments, the processing unit  1308  is configured to send information from the contact intensity module, the information indicating that the intensity of the touch input is available to the first software application (e.g., with the sending unit  1318 ). 
     In some embodiments, the processing unit  1308  is configured to repeat the operations of determining an intensity of the touch input, determining an intensity stage of the touch input, and sending touch information while the touch input is detected on the touch-sensitive surface unit  1304  (e.g., with the repeating unit  1320 , the determining unit  1312 , the sending unit  1318 , and/or the touch-sensitive surface unit  1304 ). 
     In some embodiments, the processing unit  1308  is configured to determine one or more intensity-based progress values of the touch input based on an intensity range associated with the determined intensity stage (e.g., with the determining unit  1312 ); and send touch information to the first software application (e.g., with the sending unit  1318 ), wherein the touch information includes the one or more intensity-based progress values of the touch input and information identifying the intensity stage of the touch input. 
     In some embodiments, the one or more intensity-based progress values of the touch input include a transition progress value of the touch input. 
     In some embodiments, the one or more intensity-based progress values of the touch input include a stage progress value of the touch input. 
     In some embodiments, the processing unit  1308  is configured to, in response to detecting the touch input, determine a first intensity applied by the touch input on the touch-sensitive surface unit  1304  (e.g., with the determining unit  1312 ); in accordance with a determination that the first intensity applied by the touch input on the touch-sensitive surface unit  1304  does not satisfy a stage activation intensity threshold for a second intensity stage, determine that the touch input is in a first intensity stage that is distinct from the second intensity stage (e.g., with the determining unit  1312 ); subsequent to determining that the touch input is in the first intensity stage, determine a second intensity applied by the touch input on the touch-sensitive surface unit  1304  (e.g., with the determining unit  1312 ), wherein the second intensity is distinct from the first intensity; and, in accordance with a determination that the second intensity applied by the touch input on the touch-sensitive surface unit  1304  satisfies the stage activation intensity threshold for the second intensity stage, determine that the touch input is in the second intensity stage (e.g., with the determining unit  1312 ). 
     In some embodiments, the processing unit  1308  is configured to, subsequent to determining that the touch input is in the second intensity stage, determine a third intensity applied by the touch input on the touch-sensitive surface unit  1304  (e.g., with the determining unit  1312 ), wherein the third intensity is distinct from the second intensity; in accordance with a determination that the third intensity does not satisfy a stage release intensity threshold for the second intensity stage, distinct from the stage activation intensity threshold for the second intensity stage, determine that the touch input remains in the second intensity stage (e.g., with the determining unit  1312 ); subsequent to determining that the touch input remains in the second intensity stage, determine a fourth intensity applied by the touch input on the touch-sensitive surface unit  1304  (e.g., with the determining unit  1312 ), wherein the fourth intensity is distinct from the third intensity; and, in accordance with a determination that the fourth intensity satisfies the stage release intensity threshold for the second intensity stage, determine that the touch input is in the first intensity stage (e.g., with the determining unit  1312 ). 
     In some embodiments, the processing unit  1308  is configured to, subsequent to determining that the touch input remains in the second intensity stage, determine a third intensity applied by the touch input on the touch-sensitive surface unit  1304  (e.g., with the determining unit  1312 ), wherein the third intensity is distinct from the second intensity; and, in accordance with a determination that the third intensity satisfies a stage activation threshold for the third intensity stage, distinct from the stage activation intensity threshold for the second intensity stage, determine that the touch input is in the third intensity stage (e.g., with the determining unit  1312 ). 
     In some embodiments, the processing unit  1308  is configured to, subsequent to determining that the touch input is in the third intensity stage, determine a fourth intensity applied by the touch input on the touch-sensitive surface unit  1304  (e.g., with the determining unit  1312 ), wherein the fourth intensity is distinct from the third intensity; and, in accordance with a determination that the fourth intensity satisfies a stage release intensity threshold for the third intensity stage, distinct from the stage activation threshold for the third intensity stage, determine that the touch input is in the second intensity stage (e.g., with the determining unit  1312 ). 
     In some embodiments, the processing unit  1308  is configured to identify an intensity model identifier from a plurality of predefined intensity model identifiers (e.g., with the identifying unit  1314 ), wherein the intensity stage of the touch input is selected from a plurality of intensity stages that correspond to the identified intensity model identifier. 
     In accordance with some embodiments,  FIG.  14    shows a functional block diagram of electronic device  1400  configured in accordance with the principles of the various described embodiments. The functional blocks of the device are, optionally, implemented by hardware, software, firmware, or a combination thereof to carry out the principles of the various described embodiments. It is understood by persons of skill in the art that the functional blocks described in  FIG.  14    are, optionally, combined or separated into sub-blocks to implement the principles of the various described embodiments. Therefore, the description herein optionally supports any possible combination or separation or further definition of the functional blocks described herein. 
     As shown in  FIG.  14   , electronic device  1400  includes display unit  1402  configured to display a user interface, touch-sensitive surface unit  1404  configured to receive contacts, one or more sensor units  1406  configured to detect intensity of contacts with the touch-sensitive surface unit  1404 , one or more tactile output units  1408 ; and processing unit  1410  coupled with display unit  1402 , the touch-sensitive surface unit  1404 , the one or more sensor units  1406 , and the one or more tactile output units  1408 . In some embodiments, the processing unit  1410  includes: detecting unit  1412 , determining unit  1414 , identifying unit  1416 , generating unit  1418 , selecting unit  1420 , sending unit  1422 , receiving unit  1424 , processing unit  1426 , and foregoing unit  1428 . 
     The processing unit  1410  is configured to: detect a first touch input on the touch-sensitive surface unit  1404  (e.g., with the determining unit  1414  and/or the touch-sensitive surface unit  1404 ); in response to detecting the first touch input on the touch-sensitive surface unit  1404 , determine a first intensity applied by the first touch input on the touch-sensitive surface unit  1404  (e.g., with the determining unit  1414 , the touch-sensitive surface unit  1404 , and/or the sensor units  1406 ); identify a first intensity model identifier from a plurality of predefined intensity model identifiers (e.g., with the identifying unit  1416 ); in accordance with the first intensity applied by the first touch input on the touch-sensitive surface unit  1404  and one or more thresholds associated with the first intensity model identifier, determine a first touch characterization parameter (e.g., with the determining unit  1414 ); and, subsequent to determining the first touch characterization parameter, send first touch information to a first software application (e.g., with the sending unit  1422 ), wherein the first touch information includes the first intensity model identifier and the first touch characterization parameter. 
     In some embodiments, the processing unit  1410  is configured to, in response to detecting the first touch input on the touch-sensitive surface unit  1404 , generate a tactile output in accordance with the intensity applied by the first touch input on the touch-sensitive surface unit  1404  and the one or more thresholds associated with the first intensity model identifier (e.g., with the generating unit  1418  and/or the tactile output units  1408 ). 
     In some embodiments, the processing unit  1410  is configured to: receive one or more instructions from the first software application to generate a tactile output (e.g., with the receiving unit  1424 ); and, in response to receiving the one or more instructions from the software application, generate the tactile output in accordance with the one or more instructions from the software application (e.g., with the generating unit  1418  and/or the tactile output units  1408 ). 
     In some embodiments, the processing unit  1410  is configured to, while continuing to detect the first touch input on the touch-sensitive surface unit  1404 : receive one or more instructions to use an intensity model that corresponds to a second intensity model identifier that is distinct from the first intensity model identifier (e.g., with the receiving unit  1424 ); and, subsequent to receiving the one or more instructions to use the intensity model that corresponds to the second intensity model identifier: determine a second intensity applied by the first touch input on the touch-sensitive surface unit  1404  (e.g., with the determining unit  1414 , the touch-sensitive surface unit  1404 , and/or the sensor units  1406 ); and process the first touch input based on the second intensity model identifier (e.g., with the processing unit  1426 ). 
     In some embodiments, the processing unit  1410  is configured to, while continuing to detect the first touch input on the touch-sensitive surface unit  1404 : subsequent to processing the first touch input based on the second intensity model identifier, receive one or more instructions to use an intensity model that corresponds to a third intensity model identifier that is distinct from the first intensity model identifier and the second intensity model identifier (e.g., with the receiving unit  1424 ); and, subsequent to receiving the one or more instructions to use the intensity model that corresponds to the third intensity model identifier: determine a third intensity applied by the first touch input on the touch-sensitive surface unit  1404  (e.g., with the determining unit  1414 , the touch-sensitive surface unit  1404 , and/or the sensor units  1406 ); and process the first touch input based on the third intensity model identifier (e.g., with the processing unit  1426 ). 
     In some embodiments, the processing unit  1410  is configured to: determine that the first touch input has ceased to be detected on the touch-sensitive surface unit  1404  (e.g., with the determining unit  1414 ); and, subsequent to determining that the first touch input has ceased to be detected on the touch-sensitive surface unit  1404 : detect a second touch input on the touch-sensitive surface unit  1404  that is separate from the first touch input (e.g., with the detecting unit  1412  and/or the touch-sensitive surface unit  1404 ); and process the second touch input based on the first intensity model identifier (e.g., with the processing unit  1426 ). 
     In some embodiments, processing the touch input based on the second intensity model identifier includes: in accordance with the second intensity applied by the touch input on the touch-sensitive surface unit  1404  and one or more thresholds associated with the second intensity model identifier, determining a second touch characterization parameter (e.g., with the determining unit  1414 ), wherein the second touch characterization parameter is distinct from the first touch characterization parameter; and, subsequent to determining the second touch characterization parameter, sending second touch information to the first software application (e.g., with the sending unit  1422 ), wherein the second touch information includes the second intensity model identifier and the second touch characterization parameter. 
     In some embodiments, processing the touch input based on the second intensity model identifier includes: foregoing generation of a tactile output in accordance with the second intensity failing to satisfying the one or more thresholds associated with the second intensity model identifier (e.g., with the foregoing unit  1428 , the generating unit  1418 , and/or the tactile output units  1408 ), wherein the electronic device is configured to generate a tactile output in accordance with the second intensity satisfying at least one of the one or more thresholds associated with the first intensity model identifier. 
     In some embodiments, the processing unit  1410  is configured to: subsequent to detecting the first touch input, receive one or more instructions to use an intensity model that corresponds to a second intensity model identifier that is distinct from the first intensity model identifier (e.g., with the receiving unit  1424 ); and, subsequent to receiving the one or more instructions to use the intensity model that corresponds to the second intensity model identifier: detect a second touch input on the touch-sensitive surface unit  1404  (e.g., with the detecting unit  142  and/or the touch-sensitive surface unit  1404 ); in response to detecting the second touch input on the touch-sensitive surface unit  1404 , determine a second intensity applied by the second touch input on the touch-sensitive surface unit  1404  (e.g., with the determining unit  1414 , the touch-sensitive surface unit  1404 , and/or the sensor units  1406 ); and process the second touch input based on the second intensity model identifier (e.g., with the processing unit  1426 ). 
     In some embodiments, the processing unit  1410  is configured to send a stream of intensity events to the first software application (e.g., with the sending unit  1422 ), each intensity event corresponding to an intensity applied by the touch input at a corresponding time. 
     In some embodiments, the processing unit  1410  is configured to select a set of thresholds, from a plurality of sets of thresholds, in accordance with the identified intensity model identifier (e.g., with the selecting unit  1420 ), and determine the touch characterization parameter in accordance with the selected set of thresholds (e.g., with the determining unit  1414 ). 
     In some embodiments, the processing unit  1410  is configured to identify one or more intensity ranges, in accordance with the identified intensity model identifier (e.g., with the identifying unit  1416 ), and determine a touch characterization parameter in accordance with the one or more identified intensity ranges (e.g., with the determining unit  1414 ). 
     In some embodiments, identifying the first intensity model identifier includes identifying the first software application as corresponding to the touch input and identifying an intensity model identifier registered by the first software application as the first intensity model identifier (e.g., with the identifying unit  1416 ). 
     In accordance with some embodiments,  FIG.  15    shows a functional block diagram of electronic device  1500  configured in accordance with the principles of the various described embodiments. The functional blocks of the device are, optionally, implemented by hardware, software, firmware, or a combination thereof to carry out the principles of the various described embodiments. It is understood by persons of skill in the art that the functional blocks described in  FIG.  15    are, optionally, combined or separated into sub-blocks to implement the principles of the various described embodiments. Therefore, the description herein optionally supports any possible combination or separation or further definition of the functional blocks described herein. 
     As shown in  FIG.  15   , electronic device  1500  includes display unit  1502  configured to display a user interface, touch-sensitive surface unit  1504  configured to receive contacts, one or more sensor units  1506  configured to detect intensity of contacts with the touch-sensitive surface unit  1504 , one or more tactile output units  1508 ; and processing unit  1510  coupled with display unit  1502 , the touch-sensitive surface unit  1504 , the one or more sensor units  1506 , and the one or more tactile output units  1508 . In some embodiments, the processing unit  1510  includes: detecting unit  1512 , identifying unit  1514 , determining unit  1516 , sending unit  1518 , generating unit  1520 , selecting unit  1522 , foregoing unit  1524 , and display enabling unit  1526 . 
     The processing unit  1510  is configured to: detect a first touch input on a first touch region of the touch-sensitive surface unit  1504  (e.g., with the detecting unit  1512  and/or the touch-sensitive surface unit  1504 ); identify a first intensity model identifier, associated with the first touch region of the touch-sensitive surface unit  1504 , from a plurality of predefined intensity model identifiers (e.g., with the identifying unit  1514 ); in response to detecting the first touch input on the first touch region of the touch-sensitive surface unit  1504 : determine a first intensity applied by the first touch input on the first touch region of the touch-sensitive surface unit  1504  (e.g., with the determining unit  1516 , the touch-sensitive surface unit  1504 , and/or the sensor units  1506 ); in accordance with the first intensity applied by the first touch input on the touch-sensitive surface unit  1504  and one or more thresholds associated with the first intensity model identifier, determine a first touch characterization parameter (e.g., with the determining unit  1516 ); and, subsequent to determining the first touch characterization parameter, send first touch information to the first software application (e.g., with the sending unit  1518 ), wherein the first touch information includes the first touch characterization parameter; detect a second touch input on a second touch region of the touch-sensitive surface unit  1504  (e.g., with the detecting unit  1512  and/or the touch-sensitive surface unit  1504 ), wherein the second touch region of the touch-sensitive surface unit  1504  is distinct from the first touch region of the touch-sensitive surface unit  1504 ; identify a second intensity model identifier, associated with the second touch region of the touch-sensitive surface unit  1504 , from the plurality of predefined intensity model identifiers (e.g., with the identifying unit  1514 ); and, in response to detecting the second touch input on the second touch region of the touch-sensitive surface unit  1504 : determine a second intensity applied by the second touch input on the second touch region of the touch-sensitive surface unit  1504  (e.g., with the determining unit  1516 , the touch-sensitive surface unit  1504 , and/or the sensor units  1506 ); in accordance with the second intensity applied by the second touch input on the touch-sensitive surface unit  1504  and one or more thresholds associated with the second intensity model identifier, determine a second touch characterization parameter (e.g., with the determining unit  1516 ); and, subsequent to determining the second touch characterization parameter, send second touch information to the first software application (e.g., with the sending unit  1518 ), wherein the second touch information includes the second touch characterization parameter. 
     In some embodiments, the processing unit  1510  is configured to, prior to detecting the first touch input, enable display of a user interface that includes a first display region and a second display region (e.g., with the display enabling unit  1526  and/or the display unit  1502 ), wherein the first display region corresponds to the first touch region and the second display region corresponds to the second touch region. 
     In some embodiments, the first display region corresponds to a user interface of the first software application and the second display region corresponds to a user interface of a second software application. 
     In some embodiments, the processing unit  1510  is configured to: in response to detecting the first touch input on the first touch region of the touch-sensitive surface unit  1504 , generate a first tactile output in accordance with the first intensity applied by the first touch input on the touch-sensitive surface unit  1504  and the one or more thresholds associated with the first intensity model identifier (e.g., with the generating unit  1520  and/or the tactile output units  1508 ); and, in response to detecting the second touch input on the second touch region of the touch-sensitive surface unit  1504 , generate a second tactile output in accordance with the second intensity applied by the second touch input on the touch-sensitive surface unit  1504  and the one or more thresholds associated with the second intensity model identifier (e.g., with the generating unit  1520  and/or the tactile output units  1508 ). 
     In some embodiments, at least a portion of the first touch region overlaps with at least a portion of the second touch region. 
     In some embodiments, the processing unit  1510  is configured to: detect a third touch input on an overlapping touch region, of the touch-sensitive surface unit  1504 , that corresponds to an overlap of the first touch region and the second touch region (e.g., with the detecting unit  1512  and/or the touch-sensitive surface unit  1504 ); select an intensity model identifier between the first intensity model identifier and the second intensity model identifier for the overlapping touch region (e.g., with the selecting unit  1522 ); and, in response to detecting the third touch input on the overlapping touch region: determine a third intensity applied by the third touch input on the overlapping touch region of the touch-sensitive surface unit  1504  (e.g., with the determining unit  1516 , the touch-sensitive surface unit  1504 , and/or the sensor units  1506 ); in accordance with the third intensity applied by the third touch input on the overlapping touch region of the touch-sensitive surface unit  1504  and one or more thresholds associated with the selected intensity model identifier, determine a third touch characterization parameter (e.g., with the determining unit  1516 ); and, subsequent to determining the third touch characterization parameter, send third touch information to the first software application (e.g., with the sending unit  1518 ), wherein the third touch information includes the third touch characterization parameter. 
     In some embodiments, both the first intensity model identifier and the second intensity model identifier are associated with priorities applicable to the overlapping touch region, and the intensity model identifier is selected based on the priorities of the first intensity model identifier and the second intensity model identifier for the overlapping touch region. 
     In some embodiments, the processing unit  1510  is configured to forego determination of a touch characterization parameter in accordance with the third intensity and one or more thresholds associated with an intensity model identifier that has not been selected between the first intensity model identifier and the second intensity model identifier (e.g., with the foregoing unit  1524  and/or the determining unit  1516 ). 
     In some embodiments, the first intensity model identifier has been selected for the overlapping region (e.g., by the selecting unit  1518 ), and the processing unit  1510  is configured to: subsequent to detecting the third touch input, detect a fourth touch input on the overlapping region of the touch-sensitive surface unit  1504  (e.g., with the detecting unit  1512  and/or the touch-sensitive surface unit  1504 ); and select the second intensity model identifier for the overlapping touch region (e.g., with the selecting unit  1522 ); and, in response to detecting the fourth touch input on the overlapping touch region: determine a fourth intensity applied by the fourth touch input on the overlapping touch region of the touch-sensitive surface unit  1504  (e.g., with the determining unit  1516 , the touch-sensitive surface unit  1504 , and/or the sensor units  1506 ); in accordance with the fourth intensity applied by the fourth touch input on the overlapping touch region of the touch-sensitive surface unit  1504  and the one or more thresholds associated with the second intensity model identifier, determine a fourth touch characterization parameter (e.g., with the determining unit  1516 ); and, subsequent to determining the touch characterization parameter, send fourth touch information to the first software application (e.g., with the sending unit  1518 ), wherein the fourth touch information includes the fourth touch characterization parameter. 
     In accordance with some embodiments,  FIG.  16    shows a functional block diagram of electronic device  1600  configured in accordance with the principles of the various described embodiments. The functional blocks of the device are, optionally, implemented by hardware, software, firmware, or a combination thereof to carry out the principles of the various described embodiments. It is understood by persons of skill in the art that the functional blocks described in  FIG.  16    are, optionally, combined or separated into sub-blocks to implement the principles of the various described embodiments. Therefore, the description herein optionally supports any possible combination or separation or further definition of the functional blocks described herein. 
     As shown in  FIG.  16   , electronic device  1600  includes display unit  1602  configured to display a user interface, touch-sensitive surface unit  1604  configured to receive contacts, one or more sensor units  1606  configured to detect intensity of contacts with the touch-sensitive surface unit  1604 , one or more tactile output units  1608 ; and processing unit  1610  coupled with display unit  1602 , the touch-sensitive surface unit  1604 , the one or more sensor units  1606 , and the one or more tactile output units  1608 . In some embodiments, the processing unit  1610  includes: detecting unit  1612 , processing unit  1614 , providing unit  1616 , determining unit  1618 , identifying unit  1620 , generating unit  1622 , display enabling unit  1624 , selecting unit  1626 , updating unit  1628 , and foregoing unit  1630 . 
     The processing unit  1610  is configured to: detect a touch input on the touch-sensitive surface unit  1604  (e.g., with the detecting unit  1612  and/or the touch-sensitive surface unit  1604 ); and, in response to detecting the touch input: in accordance with a determination that the touch input is at a location on the touch-sensitive surface unit  1604  that is associated with a first intensity model of a plurality of different intensity models, process the touch input in accordance with an intensity applied by the touch input on the touch-sensitive surface unit  1604  and the first intensity model (e.g., with the processing unit  1614 ); and, in accordance with a determination that the touch input is at a location on the touch-sensitive surface unit  1604  that is associated with a second intensity model different from the first intensity model, process the touch input in accordance with an intensity applied by the touch input on the touch-sensitive surface unit  1604  and the second intensity model (e.g., with the processing unit  1614 ). 
     In some embodiments, processing the touch input in accordance with an intensity applied by the touch input and the first intensity model includes providing contact intensity information to a user-interface application without generating a tactile output for the touch input (e.g., with the providing unit  1616 ); and processing the touch input in accordance with an intensity applied by the touch input and the second intensity model includes conditionally generating a tactile output for the touch input (e.g., with the generating unit  1622  and/or the tactile output units  1608 ). 
     In some embodiments, during the touch input, the electronic device  1600  detects application of a respective intensity on the touch-sensitive surface unit  1604  that is attributed to the touch input (e.g., with the detecting unit  1612 , the touch-sensitive surface unit  1604 , the determining unit  1618 , and/or the sensor units  1606 ). Processing the touch input in accordance with an intensity applied by the touch input on the touch-sensitive surface unit  1604  and the first intensity model includes providing, to a user interface application, first touch input state information that indicates that the touch input has applied the respective intensity on the touch-sensitive surface unit  1604  without generating a tactile output for the touch input (e.g., with the providing unit  1616 ); and processing the touch input in accordance with an intensity applied by the touch input on the touch-sensitive surface unit  1604  and the second intensity model includes providing, to a user interface application, second touch input state information that indicates that the touch input has applied the respective intensity on the touch-sensitive surface unit  1604  (e.g., with the providing unit  1616 ) and generating a tactile output for the touch input (e.g., with the generating unit  1622  and/or the tactile output unit  1608 ). 
     In some embodiments, the first touch input state information includes a continuously variable representation of intensity of the touch input; and the second touch input state information includes an indication that the intensity of the touch input is within a range of values that correspond to activation of a user interface element that corresponds to the location on the touch-sensitive surface unit  1604  that is associated with the second intensity model. 
     In some embodiments, the processing unit  1610  is configured to: detect a first touch input on a first touch region of the touch-sensitive surface unit  1604  (e.g., with the detecting unit  1612  and/or the touch-sensitive surface unit  1604 ); identify a first intensity model identifier, associated with the first touch region of the touch-sensitive surface unit  1604 , from a plurality of predefined intensity model identifiers (e.g., with the identifying unit  1620 ); in response to detecting the first touch input on the first touch region of the touch-sensitive surface unit  1604 : determine a first intensity applied by the first touch input on the first touch region of the touch-sensitive surface unit  1604  (e.g., with the determining unit  1618 , the touch-sensitive surface unit  1604 , and/or the sensor units  1606 ); and, in accordance with the first intensity applied by the first touch input on the touch-sensitive surface unit  1604  and the first intensity model identifier: process the first touch input (e.g., with the processing unit  1614 ); and forego generation of a tactile output for the first touch input (e.g., with the foregoing unit  1630 , the generating unit  1622 , and/or the tactile output units  1608 ); detect a second touch input on a second touch region of the touch-sensitive surface unit  1604  (e.g., with the detecting unit  1612  and/or the touch-sensitive surface unit  1604 ), wherein the second touch region of the touch-sensitive surface unit  1604  is distinct from the first touch region of the touch-sensitive surface unit  1604 ; identify a second intensity model identifier, associated with the second touch region of the touch-sensitive surface unit  1604 , from the plurality of predefined intensity model identifiers (e.g., with the identifying unit  1620 ); and, in response to detecting the second touch input on the second touch region of the touch-sensitive surface unit  1604 : determine a second intensity applied by the second touch input on the second touch region of the touch-sensitive surface unit  1604  (e.g., with the determining unit  1618 , the touch-sensitive surface unit  1604 , and/or the sensor units  1606 ); and, in accordance with the second intensity applied by the second touch input on the touch-sensitive surface unit  1604  and the second intensity model identifier: process the second touch input (e.g., with the processing unit  1614 ); and conditionally generate a tactile output for the second touch input in accordance with the second touch input and one or more model parameters associated with the second intensity model identifier (e.g., with the generating unit  1622  and/or the tactile output units  1608 ). 
     In some embodiments, conditionally generating the tactile output for the second touch input includes foregoing generation of the tactile output for the second touch input in accordance with a determination that the second touch input fails to satisfy one or more criteria corresponding to the one or more model parameters associated with the second intensity model identifier (e.g., with the foregoing unit  1630 , the generating unit  1622 , and/or the tactile output units  1608 ). 
     In some embodiments, the first intensity model identifier indicates that no tactile output is to be generated for a touch input on the first touch region of the touch-sensitive surface unit  1604 . 
     In some embodiments, the electronic device  1600  stores a first software application, and the first user input and the second user input are detected (e.g., with the detecting unit  1612  and/or the touch-sensitive surface unit  1604 ) while the electronic device  1600  displays a user interface of the first software application (e.g., with the display enabling unit  1624  and/or the display unit  1602 ). 
     In some embodiments, the user interface of the first software application includes a handwriting input tool region. 
     In some embodiments, the handwriting input tool region includes a plurality of selection regions, and at least a respective selection region of the one or more selection regions corresponds to the second touch region of the touch-sensitive surface unit  1604 . 
     In some embodiments, the handwriting input tool region includes a handwriting input region, and the handwriting input region corresponds to the first touch region of the touch-sensitive surface unit  1604 . 
     In some embodiments, the processing unit  1610  is configured to, in response to detecting the first touch input on the first touch region of the touch-sensitive surface unit  1604 , enable display of one or more graphical elements in the handwriting input region in accordance with the first touch input (e.g., with the display enabling unit  1624  and/or the display unit  1602 ). 
     In some embodiments, the processing unit  1610  is configured to, in response to detecting the first touch input on the first touch region of the touch-sensitive surface unit  1604 , enable display of a plurality of groups of characters in the plurality of selection regions (e.g., with the display enabling unit  1624  and/or the display unit  1602 ), wherein a respective group of characters is selected based on the one or more displayed graphical elements in the handwriting input region, and the respective group of characters is displayed in a respective selection region; and, in response to detecting the second user input on the second touch region of the touch-sensitive surface unit  1604  at a location that corresponds to the respective selection region, select the respective group of characters (e.g., with the selecting unit  1626 ). 
     In some embodiments, processing the first touch input detected on the first touch region of the touch-sensitive surface unit  1604  includes: determining that the first touch input has satisfied a drawing intensity threshold (e.g., with the determining unit  1618 ); and, in accordance with a determination that the first touch input has exceeded the drawing intensity threshold, enabling display of the one or more graphical elements in the handwriting input region in accordance with the first touch input (e.g., with the display enabling unit  1624  and/or the display unit  1602 ), wherein a first terminal region of a respective graphical element of the one or more graphical elements corresponds to a location where the first touch input has been determined to satisfy the drawing intensity threshold. 
     In some embodiments, processing the first touch input detected on the first touch region of the touch-sensitive surface unit  1604  includes: while continuing to detect the first touch input on the touch-sensitive surface unit  1604 , continue to update the one or more graphical elements in the handwriting input region in accordance with the first touch input regardless of whether the first touch input has ceased to satisfy the drawing intensity threshold (e.g., with the updating unit  1628 ). 
     In some embodiments, processing the first touch input detected on the first touch region of the touch-sensitive surface unit  1604  includes: detecting that the first touch input has ceased to be detected on the touch-sensitive surface unit  1604  (e.g., with the detecting unit  1612  and/or the touch-sensitive surface unit  1604 ) and detecting that the first touch input has resumed contact with the touch-sensitive surface unit  1604  within a predefined time interval subsequent to the first touch input ceasing to be detected on the touch-sensitive surface unit  1604  (e.g., with the detecting unit  1612  and/or the touch-sensitive surface unit  1604 ); and, in response to the first touch input resuming contact with the touch-sensitive surface unit  1604  within the predefined time interval subsequent to the first touch input ceasing to be detected on the touch-sensitive surface unit  1604 , updating the one or more graphical elements in the handwriting input region in accordance with the first touch input (e.g., with the updating unit  1628 ). 
     In accordance with some embodiments,  FIG.  17    shows a functional block diagram of electronic device  1700  configured in accordance with the principles of the various described embodiments. The functional blocks of the device are, optionally, implemented by hardware, software, firmware, or a combination thereof to carry out the principles of the various described embodiments. It is understood by persons of skill in the art that the functional blocks described in  FIG.  17    are, optionally, combined or separated into sub-blocks to implement the principles of the various described embodiments. Therefore, the description herein optionally supports any possible combination or separation or further definition of the functional blocks described herein. 
     As shown in  FIG.  17   , electronic device  1700  includes display unit  1702  configured to display a user interface, touch-sensitive surface unit  1704  configured to receive contacts, one or more sensor units  1706  configured to detect intensity of contacts with the touch-sensitive surface unit  1704 ; and processing unit  1708  coupled with display unit  1702 , the touch-sensitive surface unit  1704  and the one or more sensor units  1706 . In some embodiments, the processing unit  1708  includes: display enabling unit  1710 , detecting unit  1712 , processing unit  1714 , activating unit  1716 , sending unit  1718 , and updating unit  1720 . 
     The processing unit  1708  is configured to: enable display of a user interface that includes two or more display regions, including a first display region and a second display region (e.g., with the display enabling unit  1710  and/or the display unit  1702 ); and, while displaying the user interface: detect a first intensity applied by a touch input at a first location on the touch-sensitive surface unit  1704  that corresponds to the first display region (e.g., with the detecting unit  1712 , the touch-sensitive surface unit  1704 , and/or the sensor units  1706 ); detect a movement of the touch input across the touch-sensitive surface unit  1704  from the first location on the touch-sensitive surface unit  1704  to a second location on the touch-sensitive surface unit  1704  that corresponds to the second display region (e.g., with the detecting unit  1712  and/or the touch-sensitive surface unit  1704 ); after detecting the movement of the touch input from the first location on the touch-sensitive surface unit  1704  to the second location on the touch-sensitive surface unit  1704 , detect a second intensity applied by the touch input at the second location on the touch-sensitive surface unit  1704  (e.g., with the detecting unit  1712 , the touch-sensitive surface unit  1704 , and/or the sensor units  1706 ); and, in response to detecting the second intensity applied by the touch input at the second location on the touch-sensitive surface unit  1704 : in accordance with a determination that the first intensity does not satisfy a first intensity threshold, process the second intensity in accordance with one or more intensity thresholds associated with the second display region (e.g., with the processing unit  1714 ); and, in accordance with a determination that the first intensity satisfies the first intensity threshold, process the second intensity in accordance with one or more intensity thresholds associated with the first display region (e.g., with the processing unit  1714 ). 
     In some embodiments, the processing unit  1708  is configured to: send first touch information to the first software application in accordance with a determination that the first intensity satisfies a reporting intensity threshold that is distinct from the first intensity threshold, the first touch information including one or more touch parameters that correspond to the first intensity (e.g., with the sending unit  1718 ); and send second touch information to the first software application in accordance with a determination that the second intensity satisfies the reporting intensity threshold, the second touch information including one or more touch parameters that correspond to the second intensity (e.g., with the sending unit  1718 ). 
     In some embodiments, a first display region of the two or more display regions is associated with a first software element of the first software application and a second display region of the two or more display regions is associated with a second software element of the second software application. 
     In some embodiments, in accordance with the determination that the first intensity does not satisfy the first intensity threshold, the second touch information is sent to the second software element without sending the second touch information to the first software element (e.g., with the sending unit  1718 ). 
     In some embodiments, in accordance with the determination that the first intensity satisfies the first intensity threshold, the second touch information is sent to the first software element without sending the second touch information to the second software element (e.g., with the sending unit  1718 ). 
     In some embodiments, in accordance with the determination that the first intensity satisfies the reporting intensity threshold, the first touch information is sent to the first software element (e.g., with the sending unit  1718 ). 
     In some embodiments, the processing unit  1708  is configured to, in response to detecting the touch input, update the user interface in accordance with the first touch information using the first software application prior to the first intensity satisfying the first intensity threshold (e.g., with the updating unit  1720 ). 
     In some embodiments, the first intensity threshold is distinct from an activation intensity threshold. 
     In some embodiments, the one or more intensity thresholds associated with the first display region are different from the one or more intensity thresholds associated with the second display region. 
     In some embodiments, the one or more intensity thresholds associated with the first display region are the same as the one or more intensity thresholds associated with the second display region. 
     In some embodiments, the processing unit  1708  is configured to, in response to detecting the first intensity applied by the touch input, process the first intensity in accordance with the one or more intensity thresholds associated with the first display region (e.g., with the processing unit  1714 ). 
     In some embodiments, processing the first intensity in accordance with the one or more intensity thresholds associated with the first display region includes enabling display of an animation that corresponds to a change in intensity applied by the touch input from a prior intensity to the first intensity (e.g., with the display enabling unit  1710  and/or the display unit  1702 ). 
     In some embodiments, processing the second intensity in accordance with the one or more intensity thresholds associated with the first display region includes enabling display of an animation that corresponds to a change in intensity applied by the touch input on the touch-sensitive surface unit  1704  (e.g., with the display enabling unit  1710  and/or the display unit  1702 ). 
     In some embodiments, processing the second intensity in accordance with the one or more intensity thresholds associated with the second display region includes enabling display of an animation that corresponds to a change in intensity applied by the touch input on the touch-sensitive surface unit  1704  (e.g., with the display enabling unit  1710  and/or the display unit  1702 ). 
     In some embodiments, the processing unit  1708  is configured to, in response to detecting the movement of the touch input from the first location on the touch-sensitive surface unit  1704  to the second location on the touch-sensitive surface unit  1704 , enable display of an animation that corresponds to a change in intensity applied by the touch input (e.g., with the display enabling unit  1710  and/or the display unit  1702 ). 
     In some embodiments, processing the second intensity in accordance with one or more intensity thresholds associated with the first display region includes activating a first control associated with the first display region (e.g., with the activating unit  1716 ). 
     In some embodiments, processing the second intensity in accordance with one or more intensity thresholds associated with the second display region includes activating a second control associated with the second display region (e.g., with the activating unit  1716 ). 
     In accordance with some embodiments,  FIG.  18    shows a functional block diagram of an electronic device  1800  configured in accordance with the principles of the various described embodiments. The functional blocks of the device are, optionally, implemented by hardware, software, or a combination of hardware and software to carry out the principles of the various described embodiments. It is understood by persons of skill in the art that the functional blocks described in  FIG.  18    are, optionally, combined or separated into sub-blocks to implement the principles of the various described embodiments. Therefore, the description herein optionally supports any possible combination or separation or further definition of the functional blocks described herein. 
     As shown in  FIG.  18   , an electronic device  1800  includes a display unit  1802  configured to display a user interface for the electronic device, a plurality of input units  1804 , including a first input unit that is configured to generate tactile outputs in response to inputs, and a second input unit that is configured to generate tactile outputs. In some embodiments, one or more of the input units  1804  includes one or more respective sensor unit(s)  1806 . The electronic device  1800  further includes a processing unit  1808  coupled to the display unit  1802 , the input units  1804 , and the sensors  1806 . In some embodiments, the processing unit  1808  includes an input indication receiving unit  1810  configured to receive an indication of an input detected by a respective input unit of the plurality of input units, and an information providing unit  1812  configured to provide, in response to receiving the indication of the input, information describing the input to an application running on the electronic device that enables the application to react to the input. 
     The processing unit  1808  further includes a reaction receiving unit  1814  configured to receive a reaction to the input from the application that indicates that a tactile output is to be generated in response to the input, and a causing unit  1816  configured to cause, in response to receiving the reaction to the input from the application, the generation of a respective tactile output. More specifically, in accordance with a determination (see operation  1114  of method  1100 ,  FIGS.  11 A- 11 C ) that the reaction was triggered by the first input device, the causing unit  1816  causes the respective tactile output to be generated at the first input device based on the reaction to the input from the application; and in accordance with a determination (see operation  1116  of method  1100 ,  FIGS.  11 A- 11 C ) that the reaction was triggered by the second input device, the causing unit  1816  causes the respective tactile output to be generated at the second input device based on the reaction to the input from the application. 
     In some embodiments, processing unit  1808  of electronic device  1800  is configured to cause the electronic device to perform any of the methods described above with reference to  FIGS.  11 A- 11 C . 
     In accordance with some embodiments,  FIG.  19    shows a functional block diagram of an electronic device  1900  configured in accordance with the principles of the various described embodiments. The functional blocks of the device are, optionally, implemented by hardware, software, or a combination of hardware and software to carry out the principles of the various described embodiments. It is understood by persons of skill in the art that the functional blocks described in  FIG.  19    are, optionally, combined or separated into sub-blocks to implement the principles of the various described embodiments. Therefore, the description herein optionally supports any possible combination or separation or further definition of the functional blocks described herein. 
     As shown in  FIG.  19   , an electronic device  1900  includes a display unit  1902  configured to display a user interface for the electronic device, and one or more input units  1904  configured to generate tactile outputs in response to inputs. In some embodiments, one or more of the input units  1904  includes one or more respective sensor unit(s)  1906 . The electronic device  1900  further includes a processing unit  1908  coupled to display unit  1902 , input units  1904 , and sensors  1906 . In some embodiments, processing unit  1908  includes an input indication receiving unit  1910  configured to receive an indication of an input detected by a respective input unit of the plurality of input units, and an information providing unit  1912  configured to provide, in response to receiving the indication of the input, information describing the input to an application running on the electronic device that enables the application to react to the input. 
     The processing unit  1908  further includes a reaction receiving unit  1914  configured to receive a reaction to the input from the application that indicates that a tactile output is to be generated in response to the input, and a causing unit  1916  configured to cause, in response to receiving the reaction to the input from the application, the generation of a respective tactile output. More specifically, in accordance with a determination (see operation  1114  of method  1100 ,  FIGS.  11 A- 11 C ) that the reaction was triggered by the first input device, the causing unit  1916  causes the respective tactile output to be generated at the first input device based on the reaction to the input from the application; and in accordance with a determination (see operation  1116  of method  1100 ,  FIGS.  11 A- 11 C ) that the reaction was triggered by the second input device, the causing unit  1916  causes the respective tactile output to be generated at the second input device based on the reaction to the input from the application. 
     In some embodiments, processing unit  1908  of electronic device  1900  is configured to cause the electronic device to perform any of the methods described above with reference to  FIGS.  11 A- 11 C . 
     The operations described above with reference to  FIGS.  6 A- 6 D,  7 A- 7 D,  8 A- 8 C,  9 A- 9 D,  10 A- 10 D,  11 A- 11 C, and  12 A- 12 C  are, optionally, implemented by components depicted in  FIGS.  1 A- 1 B  and/or  FIGS.  13 - 19   . For example, as to the operations described above with reference to  FIGS.  11 A- 11 C , receiving an indication operation  1104 , providing information describing the input operation  1106 , receiving a reaction to the input from the application operation  1108 , and causing the generation of a tactile output operation  1112  are, optionally, implemented by event sorter  170 , event recognizer  180 , and event handler  190  ( FIG.  1 B ), or by processing unit  1808  ( FIG.  18   ). Event monitor  171  in event sorter  170  detects a contact on touch-sensitive display  112 , and event dispatcher module  174  delivers the event information to application  136 - 1 . A respective event recognizer  180  of application  136 - 1  compares the event information to respective event definitions  186 , and determines whether a first contact at a first location on the touch-sensitive surface corresponds to a predefined event or sub-event, such as selection of an object on a user interface. When a respective predefined event or sub-event is detected, event recognizer  180  activates an event handler  190  associated with the detection of the event or sub-event. Event handler  190  optionally utilizes or calls data updater  176  or object updater  177  to update the application internal state  192 . In some embodiments, event handler  190  accesses a respective GUI updater  178  to update what is displayed by the application and/or accesses a tactile output generator  167  to generate a tactile output. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in  FIGS.  1 A- 1 B . 
     For another example, as to the operations described above with reference to  FIGS.  12 A- 12 C , receiving an indication operation  1204 , providing information describing the input operation  1206 , receiving a reaction to the input from the application operation  1208 , and causing the performance of operations  1210  are, optionally, implemented by event sorter  170 , event recognizer  180 , and event handler  190  ( FIG.  1 B ), or by processing unit  1908  ( FIG.  19   ). Event monitor  171  in event sorter  170  detects a contact on touch-sensitive display  112 , and event dispatcher module  174  delivers the event information to application  136 - 1 . A respective event recognizer  180  of application  136 - 1  compares the event information to respective event definitions  186 , and determines whether a first contact at a first location on the touch-sensitive surface corresponds to a predefined event or sub-event, such as selection of an object on a user interface. When a respective predefined event or sub-event is detected, event recognizer  180  activates an event handler  190  associated with the detection of the event or sub-event. Event handler  190  optionally utilizes or calls data updater  176  or object updater  177  to update the application internal state  192 . In some embodiments, event handler  190  accesses a respective GUI updater  178  to update what is displayed by the application and/or accesses a tactile output generator  167  to generate a tactile output. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in  FIGS.  1 A- 1 B . 
     The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best use the invention and various described embodiments with various modifications as are suited to the particular use contemplated. 
     Appendix A 
     Exemplary Intensity Models 
     Stage Progression 
     In some embodiments, each stage of a fluid gesture includes three zones with specific rules governing the transition through the zones. These zones are “next,” “activated,” and “release.” In some embodiments, a stage progresses through the zones in that order given the following rules:
     1. Any stage can move to any deeper activated or next stage.   2. Any stage can move to any shallower activated or release stage provided the force is below the current stage release zone (and any shallower zone that is skipped)   3. Positive transitionProgress describes moving though a next zone.   4. Negative transitionProgress describes moving through a release zone.   5. When in neither a next or release zone, transitionProgress is 0.   6. stagePressure describes moving through the activated zone.   7. When the force is outside the activated zone of the current stage, transitionProgress shall be 0 when below the zone, or 1 when above the zone.   8. It is possible to be in both activated and next zones or, activated and release zones for the same stage. The gestureBehavior shall define if this case applies to it.   

     The chart in  FIG.  20 A  shows the stage zones for a pulse gesture. The three zones A1, A2, and A3 show the related zones for stage 1. In some embodiments, zone A1 has a stage value of 0 because the gesture is transitioning from stage 0 to stage 1 and is therefore not latched to stage 1 yet. 
     Intensity Model Identifier: Force 
       FIG.  20 B  illustrates a basic one-stage intensity model (and a corresponding gesture). Once latched to stage 1, the progress value is immediately variable. 
     Intensity Model Identifier: Gas Pedal 
       FIG.  20 C  illustrates a two-stage intensity model (and exemplary gestures) where there is a dead zone between the mouse down and the start of variable force. In some embodiments, the force band for the stage 1 activated progress is infinitely small. 
     Intensity Model Identifier: Deep Click 
       FIG.  20 D  illustrates a two-stage intensity model (and exemplary gestures) where the second stage is sometimes referred to as “deep.” In some embodiments, this is similar to camera shutter button. Each stage is surrounded by bands where an animation is prescribed. Additionally, once a device (and/or a gesture input on the device) reaches a “deep” stage, the device (and/or the gesture input on the device) remains in the “deep” stage until the gesture input ends (e.g. release to take 0). 
     Intensity Model Identifier: Pulse 
       FIG.  20 E  illustrates a two-stage intensity model (and a corresponding gesture) where the second stage is sometimes referred to as “deep.” This is similar to the deep gesture. However, it differs from the deep gesture in that the gesture input can toggle back and forth between the deep and normal stages. 
     Appendix B 
     Cocoa Application Framework 
     The Cocoa Application Framework (also referred to as the Application Kit, or AppKit) is one of the core Cocoa frameworks. It provides functionality and associated APIs for applications, including objects for graphical user interfaces (GUIs), event-handling mechanisms, application services, and drawing and image composition facilities. 
     Marking Updated APIs in Headers 
     New APIs in headers are marked with decorations that include references to “10_10_3”:
         NS_AVAILABLE_MAC(10_10_3), NS_AVAILABLE(10_10_3, &lt;iOS Release&gt;), NS_CLASS_AVAILABLE(10_10_3, &lt;iOS Release&gt;), NS_ENUM_AVAILABLE(10_10_3) or sometimes the construct:   #if MAC_OS_X_VERSION_MAX_ALLOWED&gt;=MAC_OS_X_VERSION_10_10_3   . . .   #endif
 
Runtime Version Check
       

     There are several ways to check for new features provided by the Cocoa frameworks at runtime. One is to look for a given new class or method dynamically, and not use it if not there. Another is to use the global variable NSAppKitVersionNumber (or, in Foundation, NSFoundationVersionNumber): 
     double NSAppKitVersionNumber; 
     #define NSAppKitVersionNumber10_0 577 
     #define NSAppKitVersionNumber10_1 620 
     #define NSAppKitVersionNumber10_2 663 
     #define NSAppKitVersionNumber10_3 743 
     #define NSAppKitVersionNumber10_4 824 
     #define NSAppKitVersionNumber10_5 949 
     #define NSAppKitVersionNumber10_6 1038 
     #define NSAppKitVersionNumber10_7 1138 
     #define NSAppKitVersionNumber10_8 1187 
     #define NSAppKitVersionNumber10_9 1265 
     #define NSAppKitVersionNumber10_10 1343 
     One typical use of this is to floor( ) the value, and check against the values provided in NSApplication.h. For instance: 
     
       
         
           
               
             
               
                   
               
             
            
               
                 if (floor(NSAppKitVersionNumber) &lt;= NSAppKitVersionNumber10_8) { 
               
               
                  /* On a 10.8.x or earlier system */  
               
               
                 } else if (floor(NSAppKitVersionNumber) &lt;=  
               
               
                 NSAppKitVersionNumber10_9) { 
               
               
                  /* On a 10.9-10.9.x system */  
               
               
                 } else { 
               
               
                  /* 10.10 or later system */  
               
               
                 } 
               
               
                   
               
            
           
         
       
     
     Special cases or situations for version checking are also discussed in the release notes as appropriate. For instance some individual headers may also declare the versions numbers for NSAppKitVersionNumber where some bug fix or functionality is available in a given update, for example: 
     #define NSAppKitVersionWithSuchAndSuchBadBugFix 1138.42 
     Backward Compatibility 
     One backward compatibility mechanism that is occasionally used in the frameworks is to check for the version of the system an application was built against, and if an older system, modify the behavior to be more compatible. This is done in cases where bad incompatibility problems are predicted or discovered; and most of these are listed below in these notes. 
     Typically we detect where an application was built by looking at the version of the System, Cocoa, AppKit, or Foundation frameworks the application was linked against. Thus, as a result of relinking your application against the latest SDK, you might notice different behaviors, some of which might cause incompatibilities. In these cases because the application is being rebuilt, we expect you to address these issues at the same time as well. For this reason, if you are doing a small incremental update of your application to address a few bugs, it&#39;s usually best to continue building on the same build environment and libraries used originally. 
     In some cases, we provide defaults (preferences) settings which can be used to get the old or new behavior, independent of what system an application was built against. Often these preferences are provided for debugging purposes only; in some cases the preferences can be used to globally modify the behavior of an application by registering the values (do it somewhere very early, with -[NSUserDefaults registerDefaults:]). 
     Pressure Events 
     Some Apple trackpads have the ability to report pressure. Like the rotation and magnification gestures that came before it, the pressure gesture is reported as a new event type, NSEventTypePressure, and a new responder method -(void)pressureChangeWithEvent:(NSEvent *). 
     Note: The new NSEventTypePressure events are only available in 64 bit. 
     @property (readonly) NSEventPhase phase NS_AVAILABLE_MAC(10_7); 
     NSEventTypePressure is a fluid gesture. And like all fluid gestures, it has a phase that describes the sequence of the pressure gesture stream. 
     @property (readonly) NSInteger stage NS_AVAILABLE_MAC(10_10_3); 
     A pressure gesture can go through multiple stages. 
     Stage 0: The lowest stage. Generally this means the user is applying less pressure than what is required to get a mouse down. Effectively you only see one stage 0 pressure event per stream when the gesture ends. 
     Stage 1: Equivalent to a mouse down. NSEventTypePressure events are not posted until the user applies enough pressure that the trackpad will also issue a mouse down. 
     Stage 2: Equivalent to a force click. The user has applied significant additional pressure greater than what is needed for a mouse down. Stage 2 should generally be used as the trigger for an additional action. For example, lookup is performed when the pressure stream transitions to stage 2.
 
Note: Generally, the trackpad will actuate as the gesture transitions across stages.
 
Note: It is possible for stage to increase or decrease multiple integer values per change. For example, a quick removal of the user&#39;s fingers while at stage 2 may cause stage to transition to 0 without a pressure event with stage 1.
 
@property (readonly) float pressure;
 
     The pressure on the trackpad for the current stage. The range for this value is [0,1]. Each stage has a pressure curve appropriate for that stage. That is, pressure may change from [0,1] for stage 1. And likewise, [0,1] for stage 2. 
     Note: Pressure of only one stage should be used. Carefully consider the use case. If variable input is useful for all cases, then use the pressure during stage 1 as this is the most comfortable range for the user. If variable input is useful only in rare situations where the user input must not be ambiguous with a regular mouse click, then use stage 2. Though, generally, for such cases, use stage 2 to denote this input and ignore stage 2 pressure. Do not attempt to combine stage 1 and stage 2 pressure to get a larger range. Doing so will cause undue stress on the user&#39;s fingers.
 
Note: pressure is not appropriate for weight measurements.
 
@property (readonly) CGFloat stageTransition NS_AVAILABLE_MAC(10_10_3);
 
     The animation value for stage transitions. Positive stageTransition describes approaching the next stage of the pressure gesture. Negative stageTransition describes approaching release of the current stage. For example, as the user approaches stage 2, stageTransition will increase towards 1. The moment the gesture transitions to stage 2, stageTransition immediately return to 0 and will decrease towards −1 as the user releases pressure on the trackpad until the gesture transitions to stage 1 again. Generally, only the positive stage transition values are animated. 
     Note: stageTransition doesn&#39;t match the pressure curve. There are bands where the pressure may change but the stageTransition remains at 0. stageTransition remains at 0 until the gesture is very near a stage transition. 
     @property (readonly) NSEventMask associatedEventsMask NS_AVAILABLE_MAC(10_10_3); 
     This property makes it possible to determine on the mouse down if pressure should be expected from the input device. Since pressure and mouse events are independent streams, you sometimes need to make a decision (for example, a starting pressure) immediately on mouse down. 
     Example: 
                                 if (event.associatedEventMask &amp; NSEventMaskPressure) {         self.pressure = 0; // Pressure events are coming!         } else if (event.subtype == NSTabletPointEventSubtype) {         self.pressure = event.pressure; // tablets embed pressure in the        mouse event.        } else {         self.pressure = 1; // This device does not have pressure. Default to        full pressure        }                    
Getting Pressure Events
 
     There are 3 ways to get pressure events. 
     1. Override the NSResponder method: 
     -(void)pressureChangeWithEvent:(NSEvent *)event; 
     2. In a tracking loop, add NSEventMaskPressure to the eventMask. 
                                 NSEventMask eventMask = NSLeftMouseDraggedMask |        NSLeftMouseUpMask | NSEventMaskPressure;        [self.window trackEventsMatchingMask:eventMask        timeout:NSEventDurationForever mode:NSEventTrackingRunLoopMode        handler: {circumflex over ( )} (NSEvent *event, BOOL *stop) {         if (event.type == NSEventTypePressure) {          // yay, pressure!          } else if (event.type == NSLeftMouseUpMask) {          *stop == YES;          }        }];        -OR-        NSEvent *event = [self.window        nextEventMatchingMask:NSLeftMouseDraggedMask |        NSLeftMouseUpMask | NSEventMaskPressure];                    
3. In a NSGestureRecognizer subclass by overriding the method:
 
-(void)pressureChangeWithEvent:(NSEvent *)event;
 
Spring Loaded Drag &amp; Drop
 
     The Finder spring loading feature has been expanded and adopted in more places. All application windows will spring forward automatically. Tabs will activate themselves in response to spring loading while segmented controls and buttons can be configured to respond to spring loading. 
     Spring loading is triggered by hovering over a spring loading capable target. The length of the hover delay is controlled via the Accessibility Mouse &amp; Trackpad system preference pane. 
     Using a pressure sensitive trackpad, the user can also trigger spring loading by pressing harder on the trackpad during a drag. This is akin to a nested click inside of a drag. During a drag, the user can press harder. The trackpad will actuate, arming the spring loading under the cursor. When the user relaxes just enough to release the nested click, the trackpad will actuate and trigger the spring loading without dropping the drag. Once the user triggers spring loading via a pressure sensitive trackpad, the hover feature is disabled until the user starts a new drag &amp; drop operation. 
     Spring Loaded Controls 
     Segmented controls and buttons can be configured to send their action in response to the user dragging an item. Set springLoaded to YES and the user will be able to interact with the control via force clicking or hovering during a drag. 
     @property (getter=isSpringLoaded) BOOL springLoaded NS_AVAILABLE_MAC(10_10_3); // sends action on force-click or extended hover while dragging. Defaults to NO. 
     Spring Loaded Tab View 
     Tab views and tab view controllers now change selection in response to force click or extended hover while the user is dragging an item. 
     Accelerator Buttons 
     There are new button types for pressure sensitive trackpads, referred to as “accelerator” buttons. These act like continuous-mode push buttons in that applications generally respond to them while they are held down, and then stop when they are released. Their main feature is the ability to interpret variable pressure, allowing the user to directly control the speed of the related action by changing the pressure they apply. This is intended to be used for things like controlling the speed of fast forward and rewind for media playback, the advancement speed for week view in calendar, or the zoom speed in maps. 
     There are two types of accelerator buttons:
         A “regular” type where fine-grained precision is desirable, and the range of values is a floating point number. Here the button&#39;s value is 0 when not pressed, and ranges from [1 . . . 2) when pressed.   A “multi-level” type with a configurable number of explicit levels (up to 5). These buttons also present a value of 0 when not pressed, but have an integer value from [1 . . . N] to indicate the discrete acceleration levels.       

     
       
         
           
               
             
               
                   
               
             
            
               
                 typedef NS_ENUM (NSUInteger, NSButtonType) { 
               
               
                  NSAcceleratorButton NS_ENUM_AVAILABLE_MAC (10_10_3) = 8,  
               
               
                  NSMultiLevelAcceleratorButton NS_ENUM_AVAILABLE_MAC  
               
               
                  (10_10_3) = 9,  
               
               
                 } 
               
               
                 @property NSInteger maxState NS_AVAILABLE_MAC (10_10_3); //  
               
               
                 Configures the maximum allowed state for NSMultiLevelAcceleratorButton  
               
               
                 buttons, allowed values range from [1, 5]. 
               
               
                   
               
            
           
         
       
     
     The new button types are variants of the standard NSMomentaryLightButton, and work with a variety of bezel styles. A simple call to setButtonType is all that&#39;s necessary to use them—this will properly configure relevant aspects of the button. Accelerator buttons behave differently than standard NSButtons in a variety of ways. Beyond the additional API above, here are the major behavioral distinctions:
         Accelerator buttons do not automatically advance their state when clicked, but will change value and send action messages repeatedly while interacting with the user. On mouse up, they reset their value to 0 and send a final action message.   The value of a multi-level accelerator button can be explicitly set in order to suppress lower levels of the accelerated range. This is used, for example, when a video is already fast forwarding at 4×: we provide no acceleration messages or feedback until the 8× level is reached.   Accelerator buttons allow a greater range of values: [0,1.99999 . . . ] or [0,5] compared to the standard on/off/mixed for other buttons.   The floatValue and doubleValue are used to convey pressure levels for regular accelerator buttons.   Accelerator buttons do not support mixed state.       

     All accelerator buttons will carry a state of 0 when not pressed, or 1 when pressed/clicked normally. The state (and value) will rise above 1 when pressed harder. For fine grained control over speed, NSButtonTypeAccelerator exposes a doubleValue ranging from 1 when initially pressed to 1.999999 (or so) when fully pressed. This design allows the doubleValue and integerValue to “match”, and avoids having to expose a separate property for the fractional part of the value. 
     An NSMultiLevelAcceleratorButton provides a configurable number of distinct pressure levels, with tactile feedback as the user reaches each one. Clients configure the number of discrete levels by changing the new maxState property. It is always 1 for other button types, but defaults to 2 for multi-level accelerator buttons. Values outside the range [2,5] will be pinned and cause a warning to be logged. Values above 1 will add additional levels to the button, with a light actuation, on capable hardware, when each one is reached. The control takes on these integer-valued states during interaction with the user, and sends an action message whenever they change. As an aside, note that the pressures needed to reach a given level remain the same, regardless of the maxState value. In other words, the pressure thresholds for the allowed levels are not evenly spread across the available pressure range. 
     Applications respond to accelerator buttons using the traditional action handlers. They read the control&#39;s state/integerValue or doubleValue, and configure the speed of the related operation to match. The application is responsible for translating the floating point [0,1.99999] or integer [0,5] values into an appropriate speed for their specific use case. 
     Accelerator Segmented Controls 
     Segmented controls can be configured for pressure sensitivity, which can be used to accelerate user interactions. For example, a −/+ zoom control may want to accelerate zooming the harder the user presses. A continuous control with a periodic interval may accelerate page turning, as the periodic interval is automatically adjusted based on pressure. 
     
       
         
           
               
             
               
                   
               
             
            
               
                 typedef NS_ENUM (NSUInteger, NSSegmentSwitchTracking) { 
               
               
                   NSSegmentSwitchTrackingMomentaryAccelerator  
               
               
                 NS_ENUM_AVAILABLE_MAC (10_10_3) = 3, // accelerator behavior, 
               
               
                 only selected while tracking 
               
               
                 } 
               
               
                 /* This message is valid only for  
               
               
                 trackingMode=NSSegmentSwitchTrackingMomentaryAccelerator and  
               
               
                 provides the double value for the selected segment. 
               
               
                  */  
               
               
                 - (double) doubleValueForSelectedSegment NS_AVAILABLE_MAC  
               
               
                 (10_10_3); 
               
               
                   
               
            
           
         
       
     
     The control may have its tracking mode set to NSSegmentSwitchTrackingMomentaryAccelerator. doubleValueForSelectedSegment represents the value which the individual segment would return without any segment offset, as if it were a standalone accelerator button. 
     Accelerator Segmented Control Behaviors 
     Behavior of momentary accelerator segmented controls vary based on the state of their continuous flag and whether or not the hardware supports pressure sensitivity. Below is a description of the behavior in each configuration. 
     Continuous Momentary Accelerator, Non-Pressure Sensitive Trackpad: 
     Actions will be sent at the cell&#39;s periodic interval, starting after the cell&#39;s periodic delay. Upon mouse up a final action will be sent with selectedSegment=−1. 
     Continuous Momentary Accelerator, Pressure Sensitive Trackpad: 
     Actions will be sent at a periodic interval automatically adjusted based on pressure, starting after the cell&#39;s delay. Upon mouse up a final action will be sent with selectedSegment=−1. In this configuration the adjusted periodic interval is useful for accelerated page turning of content. 
     Non-Continuous Momentary Accelerator, Non-Pressure Sensitive Trackpad: 
     An initial action will be sent with doubleValueForSelectedSegment=1.0. Upon mouse up a final action will be sent with doubleValueForSelectedSegment=0.0 and selectedSegment=−1. 
     Non-Continuous Momentary Accelerator, Pressure Sensitive Trackpad: 
     Each time the pressure changes, an action will be sent with doubleValueForSelectedSegment=[1.0+pressure]. Upon mouse up a final action will be sent with doubleValueForSelectedSegment=0.0 and selectedSegment=−1. In this configuration the doubleValueForSelectedSegment is useful to accelerate actions such as zooming.

Metadata:
Filing Date: 20210720
Publication Date: 20230117
Grant Date: 20230117
Priority Date: 20150308
Inventors: LEDET, RALEIGH J.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F3/0416", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04817", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04808", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0488", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04105", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0414", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/04817", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0414", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04883", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0414", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0416", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0488", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0416", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04105", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0488", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/3234", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0416", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04105", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0488", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0414", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/04817", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 55651217