PATENT DOCUMENT

Publication Number: US-10394441-B2
Application Number: US-201113340605-A
Country: US
Kind Code: B2

Title: Device, method, and graphical user interface for controlling display of application windows

Abstract:
An electronic device with a display and a touch-sensitive surface displays a plurality of windows on the display. The plurality of windows includes a first window for a first application displayed in a frontmost position on the display and a second window displayed in a lower position than the frontmost position. The device detects a first gesture moving in a first direction on the touch sensitive surface, the first direction on the touch sensitive surface corresponding to a first direction on the display; and, in response to detecting the first gesture moving in the first direction on the touch sensitive surface: moves the first window across the display in the first direction on the display until the first window is moved partially or fully off the display; and displays the second window in the frontmost position on the display.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a display; 
 a touch-sensitive surface; 
 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:
 displaying a plurality of windows on the display, the plurality of windows including a first window for a first application displayed in a frontmost position on the display and a second window displayed in a lower position than the frontmost position, and the plurality of windows having a layer order; 
 detecting a first gesture moving in a first direction on the touch sensitive surface, the first direction on the touch sensitive surface corresponding to a first direction on the display; and, 
 in response to detecting the first gesture moving in the first direction on the touch sensitive surface:
 moving the first window across the display in the first direction on the display until the first window is moved partially or fully off the display; 
 displaying the second window in the frontmost position on the display; and 
 maintaining the layer order of the plurality of windows. 
 
 
 
     
     
       2. The device of  claim 1 , wherein the first direction on the touch sensitive surface corresponds to a horizontal direction on the display. 
     
     
       3. The device of  claim 1 , wherein the first direction on the touch sensitive surface corresponds to a vertical direction on the display. 
     
     
       4. The device of  claim 1 , wherein the first direction on the touch sensitive surface corresponds to a diagonal direction on the display. 
     
     
       5. The device of  claim 1 , wherein the first window is moved partially off the display in response to detecting the first gesture moving in the first direction on the touch sensitive surface. 
     
     
       6. The device of  claim 1 , wherein the first window is moved fully off the display in response to detecting the first gesture moving in the first direction on the touch sensitive surface. 
     
     
       7. The device of  claim 1 , wherein the second window is for a second application, distinct from the first application. 
     
     
       8. The device of  claim 1 , including instructions for:
 after responding to the first gesture, while displaying the second window in the frontmost position on the display, detecting a second gesture moving in a direction opposite the first direction on the touch sensitive surface; and, 
 in response to detecting the second gesture moving in the direction opposite the first direction on the touch sensitive surface:
 moving the first window across the display in a direction opposite the first direction on the display; and 
 redisplaying the first window in the frontmost position on the display. 
 
 
     
     
       9. The device of  claim 8 , including instructions for:
 in response to detecting the second gesture moving in the direction opposite the first direction on the touch sensitive surface:
 maintaining a layer order of the plurality of windows. 
 
 
     
     
       10. An electronic device, comprising:
 a display; 
 a touch-sensitive surface; 
 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:
 displaying a plurality of windows on the display, the plurality of windows including a first window for a first application displayed in a frontmost position on the display and a second window displayed in a lower position than the frontmost position, and the plurality of windows having a layer order; 
 detecting a first gesture moving in a first direction on the touch sensitive surface, wherein the first gesture is a multifinger swipe gesture, the first direction on the touch sensitive surface corresponding to a first direction on the display; and, 
 in response to detecting the first gesture moving in the first direction on the touch sensitive surface:
 moving the first window across the display in the first direction on the display until the first window is moved partially or fully off the display; 
 displaying the second window in the frontmost position on the display; and 
 maintaining the layer order of the plurality of windows. 
 
 
 
     
     
       11. An electronic device, comprising:
 a display; 
 a touch-sensitive surface; 
 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:
 displaying a plurality of windows on the display, the plurality of windows including a first window for a first application displayed in a frontmost position on the display and a second window displayed in a lower position than the frontmost position, wherein the first window is one of multiple windows for the first application and the plurality of windows have a layer order; 
 
 detecting a first gesture moving in a first direction on the touch sensitive surface, the first direction on the touch sensitive surface corresponding to a first direction on the display; and, 
 in response to detecting the first gesture moving in the first direction on the touch sensitive surface:
 moving the multiple windows for the first application across the display in the first direction on the display until the multiple windows for the first application are moved partially or fully off the display; 
 displaying the second window in the frontmost position on the display; and 
 maintaining the layer order of the plurality of windows. 
 
 
     
     
       12. The device of  claim 11 , the device including instructions for:
 after responding to the first gesture, while displaying the second window in the frontmost position on the display, detecting a second gesture moving in a direction opposite the first direction on the touch sensitive surface; and, 
 in response to detecting the second gesture moving in the direction opposite the first direction on the touch sensitive surface:
 moving the multiple windows for the first application across the display in the direction opposite the first direction on the display. 
 
 
     
     
       13. An electronic device, comprising:
 a display; 
 a touch-sensitive surface; 
 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:
 displaying a plurality of windows on the display, the plurality of windows having a layer order, the plurality of windows including:
 a first window for a first application displayed in a frontmost position on the display; 
 a second window for a second application, distinct from the first application, displayed in a second position lower than the frontmost position; and 
 a third window for a third application, distinct from the first application and the second application, displayed in a third position lower than the second position; 
 
 detecting a first gesture moving in a first direction on the touch sensitive surface, the first direction on the touch sensitive surface corresponding to a first direction on the display; 
 in response to detecting the first gesture moving in the first direction on the touch sensitive surface:
 moving the first window across the display in the first direction on the display until the first window is moved partially or fully off the display; 
 displaying the second window in the frontmost position on the display; and 
 maintaining the layer order of the plurality of windows; 
 
 after responding to the first gesture, while displaying the second window in the frontmost position on the display, detecting a second gesture moving in the first direction on the touch sensitive surface; 
 in response to detecting the second gesture moving in the first direction on the touch sensitive surface:
 moving the second window across the display in the first direction on the display until the second window is moved partially or fully off the display; and 
 displaying the third window in the frontmost position on the display; 
 
 after responding to the second gesture, while displaying the third window in the frontmost position on the display, detecting a third gesture moving in a direction opposite the first direction on the touch sensitive surface; 
 in response to detecting the third gesture moving in the direction opposite the first direction on the touch sensitive surface:
 moving the second window across the display in a direction opposite the first direction on the display; and 
 redisplaying the second window in the frontmost position on the display; 
 
 after responding to the third gesture, while displaying the second window in the frontmost position on the display, detecting a fourth gesture moving in the direction opposite the first direction on the touch sensitive surface; and, 
 in response to detecting the fourth gesture moving in the direction opposite the first direction on the touch sensitive surface:
 moving the first window across the display in a direction opposite the first direction on the display; and 
 redisplaying the first window in the frontmost position on the display. 
 
 
 
     
     
       14. The device of  claim 13 , wherein the first direction on the touch sensitive surface corresponds to a horizontal direction on the display. 
     
     
       15. The device of  claim 13 , wherein the first direction on the touch sensitive surface corresponds to a vertical direction on the display. 
     
     
       16. The device of  claim 13 , wherein the first direction on the touch sensitive surface corresponds to a diagonal direction on the display. 
     
     
       17. The device of  claim 13 , wherein the first window is moved partially off the display in response to detecting the first gesture moving in the first direction on the touch sensitive surface and the second window is moved partially off the display in response to detecting the second gesture moving in the first direction on the touch sensitive surface. 
     
     
       18. The device of  claim 13 , wherein the first window is moved fully off the display in response to detecting the first gesture moving in the first direction on the touch sensitive surface and the second window is moved fully off the display in response to detecting the second gesture moving in the first direction on the touch sensitive surface. 
     
     
       19. The device of  claim 13 , wherein the second window is one of multiple windows for the second application, the device including instructions for:
 in response to detecting the second gesture moving in the first direction on the touch sensitive surface:
 moving the multiple windows for the second application across the display in the first direction on the display until the multiple windows for the second application are moved partially or fully off the display. 
 
 
     
     
       20. The device of  claim 13 , wherein the second window is one of multiple windows for the second application, the device including instructions for:
 in response to detecting the second gesture moving in the first direction on the touch sensitive surface:
 moving the multiple windows for the second application across the display in the first direction on the display until the multiple windows for the second application are moved partially or fully off the display; 
 
 in response to detecting the third gesture moving in the direction opposite the first direction on the touch sensitive surface:
 moving the multiple windows for the second application across the display in the direction opposite the first direction on the display. 
 
 
     
     
       21. The device of  claim 13 , wherein the first window is one of multiple windows for the first application, the device including instructions for:
 in response to detecting the first gesture moving in the first direction on the touch sensitive surface:
 moving the multiple windows for the first application across the display in the first direction on the display until the multiple windows for the first application are moved partially or fully off the display; 
 
 in response to detecting the fourth gesture moving in the direction opposite the first direction on the touch sensitive surface:
 moving the multiple windows for the first application across the display in the direction opposite the first direction on the display. 
 
 
     
     
       22. An electronic device, comprising:
 a display; 
 a touch-sensitive surface; 
 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:
 displaying a plurality of windows on the display, the plurality of windows having a layer order, the plurality of windows including:
 a first window for a first application displayed in a frontmost position on the display; 
 a second window for a second application, distinct from the first application, displayed in a second position lower than the frontmost position; and 
 a third window for a third application, distinct from the first application and the second application, displayed in a third position lower than the second position; 
 
 detecting a first gesture moving in a first direction on the touch sensitive surface, the first direction on the touch sensitive surface corresponding to a first direction on the display; 
 in response to detecting the first gesture moving in the first direction on the touch sensitive surface:
 moving the first window across the display in the first direction on the display until the first window is moved partially or fully off the display; 
 displaying the second window in the frontmost position on the display; and 
 maintaining the layer order of the plurality of windows; 
 
 after responding to the first gesture, while displaying the second window in the frontmost position on the display, detecting a second gesture moving in the first direction on the touch sensitive surface; 
 in response to detecting the second gesture moving in the first direction on the touch sensitive surface:
 moving the second window across the display in the first direction on the display until the second window is moved partially or fully off the display; and 
 displaying the third window in the frontmost position on the display; 
 
 after responding to the second gesture, while displaying the third window in the frontmost position on the display, detecting a third gesture moving in a direction opposite the first direction on the touch sensitive surface; 
 in response to detecting the third gesture moving in the direction opposite the first direction on the touch sensitive surface:
 moving the second window across the display in a direction opposite the first direction on the display; and 
 redisplaying the second window in the frontmost position on the display; 
 
 after responding to the third gesture, while displaying the second window in the frontmost position on the display, detecting a fourth gesture moving in the direction opposite the first direction on the touch sensitive surface; and, 
 in response to detecting the fourth gesture moving in the direction opposite the first direction on the touch sensitive surface:
 moving the first window across the display in a direction opposite the first direction on the display; and 
 redisplaying the first window in the frontmost position on the display, 
 
 wherein the first gesture, the second gesture, the third gesture, and the fourth gesture are multifinger swipe gestures. 
 
 
     
     
       23. An electronic device, comprising:
 a display; 
 a touch-sensitive surface; 
 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:
 displaying a plurality of windows on the display, the plurality of windows having a layer order, the plurality of windows including:
 a first window for a first application displayed in a frontmost position on the display, wherein the first window is one of multiple windows for the first application; 
 a second window for a second application, distinct from the first application, displayed in a second position lower than the frontmost position; and 
 a third window for a third application, distinct from the first application and the second application, displayed in a third position lower than the second position; 
 
 detecting a first gesture moving in a first direction on the touch sensitive surface, the first direction on the touch sensitive surface corresponding to a first direction on the display; 
 in response to detecting the first gesture moving in the first direction on the touch sensitive surface:
 moving the multiple windows for the first application across the display in the first direction on the display until the multiple windows for the first application are moved partially or fully off the display; 
 displaying the second window in the frontmost position on the display; and 
 maintaining the layer order of the plurality of windows; 
 
 after responding to the first gesture, while displaying the second window in the frontmost position on the display, detecting a second gesture moving in the first direction on the touch sensitive surface; 
 in response to detecting the second gesture moving in the first direction on the touch sensitive surface:
 moving the second window across the display in the first direction on the display until the second window is moved partially or fully off the display; and 
 displaying the third window in the frontmost position on the display; 
 
 after responding to the second gesture, while displaying the third window in the frontmost position on the display, detecting a third gesture moving in a direction opposite the first direction on the touch sensitive surface; 
 in response to detecting the third gesture moving in the direction opposite the first direction on the touch sensitive surface:
 moving the second window across the display in a direction opposite the first direction on the display; and 
 redisplaying the second window in the frontmost position on the display; 
 
 after responding to the third gesture, while displaying the second window in the frontmost position on the display, detecting a fourth gesture moving in the direction opposite the first direction on the touch sensitive surface; and, 
 in response to detecting the fourth gesture moving in the direction opposite the first direction on the touch sensitive surface:
 moving the first window across the display in a direction opposite the first direction on the display; and 
 redisplaying the first window in the frontmost position on the display.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/547,696, titled “Device, Method, and Graphical User Interface for Controlling Display of Application Windows,” filed Oct. 15, 2011, which is incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     This relates generally to electronic devices with touch-sensitive surfaces, including but not limited to electronic devices with touch-sensitive surfaces that display multiple application windows in a graphical user interface. 
     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 touch pads and touch screen displays. Such surfaces are widely used to manipulate user interface objects on a display. 
     Exemplary manipulations include controlling display of application windows that overlap each other when displayed, in order to bring the desired application window to the foreground. A user may need to perform such manipulations in any user interface where application windows from any number of applications are displayed. 
     But existing methods for controlling display of application windows are tedious and creates a significant cognitive burden on a user. In addition, existing methods take longer than necessary, thereby wasting energy. This latter consideration is particularly important in battery-operated devices. 
     SUMMARY 
     Accordingly, there is a need for electronic devices with faster, more efficient methods and interfaces for controlling display of application windows. Such methods and interfaces may complement or replace conventional methods for controlling display of application windows. Such methods and interfaces reduce the cognitive burden on 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 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 finger contacts and gestures on the touch-sensitive surface. In some embodiments, the functions may include image editing, drawing, presenting, word processing, website creating, disk authoring, spreadsheet making, game playing, telephoning, video conferencing, e-mailing, instant messaging, workout support, digital photographing, digital videoing, web browsing, digital music playing, and/or digital video playing. Executable instructions for performing these functions may be 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 display and a touch-sensitive surface. The method includes: displaying a plurality of windows on the display, the plurality of windows including a first window for a first application displayed in a frontmost position on the display and a second window displayed in a lower position than the frontmost position; detecting a first gesture moving in a first direction on the touch sensitive surface, the first direction on the touch sensitive surface corresponding to a first direction on the display; and, in response to detecting the first gesture moving in the first direction on the touch sensitive surface: moving the first window across the display in the first direction on the display until the first window is moved partially or fully off the display; and displaying the second window in the frontmost position on the display. 
     In accordance with some embodiments, a method is performed at an electronic device with a display and a touch-sensitive surface. The method includes: displaying a plurality of windows on the display, the plurality of windows including: a first window for a first application displayed in a frontmost position on the display; a second window for a second application, distinct from the first application, displayed in a second position lower than the frontmost position; and a third window for a third application, distinct from the first application and the second application, displayed in a third position lower than the second position; detecting a first gesture moving in a first direction on the touch sensitive surface, the first direction on the touch sensitive surface corresponding to a first direction on the display; in response to detecting the first gesture moving in the first direction on the touch sensitive surface: moving the first window across the display in the first direction on the display until the first window is moved partially or fully off the display; and displaying the second window in the frontmost position on the display; after responding to the first gesture, while displaying the second window in the frontmost position on the display, detecting a second gesture moving in the first direction on the touch sensitive surface; in response to detecting the second gesture moving in the first direction on the touch sensitive surface: moving the second window across the display in the first direction on the display until the second window is moved partially or fully off the display; and displaying the third window in the frontmost position on the display; after responding to the second gesture, while displaying the third window in the frontmost position on the display, detecting a third gesture moving in a direction opposite the first direction on the touch sensitive surface; in response to detecting the third gesture moving in the direction opposite the first direction on the touch sensitive surface: moving the second window across the display in a direction opposite the first direction on the display; and redisplaying the second window in the frontmost position on the display; after responding to the third gesture, while displaying the second window in the frontmost position on the display, detecting a fourth gesture moving in the direction opposite the first direction on the touch sensitive surface; and, in response to detecting the fourth gesture moving in the direction opposite the first direction on the touch sensitive surface: moving the first window across the display in a direction opposite the first direction on the display; and redisplaying the first window in the frontmost position on the display. 
     In accordance with some embodiments, an electronic device includes a display, a touch-sensitive surface, one or more processors, memory, and one or more programs; the one or more programs are stored in the memory and configured to be executed by the one or more processors and the one or more programs include instructions for performing the operations of any of the methods described above. In accordance with some embodiments, a graphical user interface on an electronic device with a display, a 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 above, which are updated in response to inputs, as described in any of the methods above. In accordance with some embodiments, a computer readable storage medium has stored therein instructions which when executed by an electronic device with a display, a touch-sensitive surface, cause the device to perform the operations of any of the methods described above. In accordance with some embodiments, an electronic device includes: a display, a touch-sensitive surface; and means for performing the operations of any of the methods described above. In accordance with some embodiments, an information processing apparatus, for use in an electronic device with a display and a touch-sensitive surface, includes means for performing the operations of any of the methods described above. 
     In accordance with some embodiments, an electronic device includes a display unit configured to display a plurality of windows on the display unit, the plurality of windows including a first window for a first application displayed in a frontmost position on the display unit and a second window displayed in a lower position than the frontmost position; a touch-sensitive surface unit configured to receive gestures; and a processing unit coupled to the display unit and the touch-sensitive surface unit. The processing unit is configured to: detect a first gesture moving in a first direction on the touch sensitive surface unit, the first direction on the touch sensitive surface unit corresponding to a first direction on the display unit; and, in response to detecting the first gesture moving in the first direction on the touch sensitive surface unit: move the first window across the display unit in the first direction on the display unit until the first window is moved partially or fully off the display unit; and enable display of the second window in the frontmost position on the display unit. 
     In accordance with some embodiments, an electronic device includes a display unit configured to display a plurality of windows on the display unit, the plurality of windows including: a first window for a first application displayed in a frontmost position on the display unit; a second window for a second application, distinct from the first application, displayed in a second position lower than the frontmost position; and a third window for a third application, distinct from the first application and the second application, displayed in a third position lower than the second position; a touch-sensitive surface unit configured to receive gestures; and a processing unit coupled to the display unit and the touch-sensitive surface unit. The processing unit is configured to: detect a first gesture moving in a first direction on the touch sensitive surface unit, the first direction on the touch sensitive surface unit corresponding to a first direction on the display unit; in response to detecting the first gesture moving in the first direction on the touch sensitive surface unit: move the first window across the display unit in the first direction on the display unit until the first window is moved partially or fully off the display unit; and enable display of the second window in the frontmost position on the display unit; after responding to the first gesture, while displaying the second window in the frontmost position on the display unit, detect a second gesture moving in the first direction on the touch sensitive surface unit; in response to detecting the second gesture moving in the first direction on the touch sensitive surface unit: move the second window across the display unit in the first direction on the display unit until the second window is moved partially or fully off the display unit; and enable display of the third window in the frontmost position on the display unit; after responding to the second gesture, while displaying the third window in the frontmost position on the display unit, detect a third gesture moving in a direction opposite the first direction on the touch sensitive surface unit; in response to detecting the third gesture moving in the direction opposite the first direction on the touch sensitive surface unit: move the second window across the display unit in a direction opposite the first direction on the display unit; and reenable display of the second window in the frontmost position on the display unit; after responding to the third gesture, while displaying the second window in the frontmost position on the display unit, detect a fourth gesture moving in the direction opposite the first direction on the touch sensitive surface unit; and, in response to detecting the fourth gesture moving in the direction opposite the first direction on the touch sensitive surface unit: move the first window across the display unit in a direction opposite the first direction on the display unit; and reenable display of the first window in the frontmost position on the display unit. 
     Thus, electronic devices with displays and touch-sensitive surfaces are provided with faster, more efficient methods and interfaces for controlling display of application windows, thereby increasing the effectiveness, efficiency, and user satisfaction with such devices. Such methods and interfaces may complement or replace conventional methods for controlling display of application windows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the aforementioned embodiments of the invention as well as additional embodiments thereof, 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. 1A  is a block diagram illustrating a portable multifunction device with a touch-sensitive display in accordance with some embodiments. 
         FIG. 1B  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  is a block diagram of an exemplary multifunction device with a display and a touch-sensitive surface in accordance with some embodiments. 
         FIG. 4A  illustrates an exemplary user interface for a menu of applications on a portable multifunction device in accordance with some embodiments. 
         FIG. 4B  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. 5A-5CC  illustrate exemplary user interfaces for controlling display of application windows in accordance with some embodiments. 
         FIGS. 6A-6C  are flow diagrams illustrating a method of controlling display of application windows in accordance with some embodiments. 
         FIGS. 7A-7E  are flow diagrams illustrating a method of controlling display of application windows in accordance with some embodiments. 
         FIG. 8  is a functional block diagram of an electronic device in accordance with some embodiments. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In a graphical user interface with multiple application windows, users often want to adjust how the various windows are displayed. For example, for application windows that overlap each other, a user may want to quickly go through the stack of overlapping windows to find and bring to the foreground a particular window. In some cases, the user may want to move some of the windows partially or fully off the display to unclutter the display. But existing methods for moving, hiding, and unhiding application windows typically require precise mouse/cursor manipulations of application windows or the use of memorized keyboard shortcuts. Such methods are tedious for the user. The embodiments below describe faster, simpler methods of hiding, unhiding, and otherwise controlling the display of application windows via simple, imprecise gestures (e.g., multifinger swipe gestures). In response to user gestures in one direction, windows are hidden in the order in which they are displayed. In response to user gestures in the opposite direction, windows are un-hidden in a last-hidden, first-unhidden order. If there are multiple windows corresponding to the same application, these windows may be hidden or unhidden one at a time or together all at once. 
     Below,  FIGS. 1A-1B, 2, 3, and 8  provide a description of exemplary devices.  FIGS. 4A-4B and 5A-5CC  illustrate exemplary user interfaces for controlling display of application windows.  FIGS. 6A-6C and 7A-7E  are flow diagrams illustrating methods of controlling display of application windows. The user interfaces in  FIGS. 5A-5CC  are used to illustrate the processes in  FIGS. 6A-6C and 7A-7E . 
     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 present invention. However, it will be apparent to one of ordinary skill in the art that the present invention 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. may be 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 present invention. The first contact and the second contact are both contacts, but they are not the same contact. 
     The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention 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” may be 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” may be 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 touch pads), may also be 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 touch pad). 
     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 may include 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 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 may be executed on the device may 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 may be 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 may support 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. 1A  is a block diagram illustrating portable multifunction device  100  with touch-sensitive displays  112  in accordance with some embodiments. Touch-sensitive display  112  is sometimes called a “touch screen” for convenience, and may also be known as or called a touch-sensitive display system. Device  100  may include memory  102  (which may include one or more computer readable storage mediums), memory controller  122 , one or more processing units (CPU&#39;s)  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  may include one or more optical sensors  164 . These components may communicate over one or more communication buses or signal lines  103 . 
     It should be appreciated that device  100  is only one example of a portable multifunction device, and that device  100  may have more or fewer components than shown, may combine two or more components, or may have a different configuration or arrangement of the components. The various components shown in  FIG. 1A  may be implemented in hardware, software, or a combination of both hardware and software, including one or more signal processing and/or application specific integrated circuits. 
     Memory  102  may include high-speed random access memory and may also include 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  120  and the peripherals interface  118 , may be controlled by memory controller  122 . 
     Peripherals interface  118  can be used to couple input and output peripherals of the device to CPU  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  120 , and memory controller  122  may be implemented on a single chip, such as chip  104 . In some other embodiments, they may be 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  may include 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  may communicate 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 may use 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 (HSUPA), 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 802.11b, 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 may be 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 screen  112  and other input control devices  116 , to peripherals interface  118 . I/O subsystem  106  may include display controller  156  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 control devices  116  may 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  may be coupled to any (or none) of the following: a keyboard, infrared port, USB port, and a pointer device such as a mouse. The one or more buttons (e.g.,  208 ,  FIG. 2 ) may include an up/down button for volume control of speaker  111  and/or microphone  113 . The one or more buttons may include a push button (e.g.,  206 ,  FIG. 2 ). 
     Touch-sensitive display  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 screen  112 . Touch screen  112  displays visual output to the user. The visual output may include graphics, text, icons, video, and any combination thereof (collectively termed “graphics”). In some embodiments, some or all of the visual output may correspond to user-interface objects. 
     Touch screen  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 screen  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 screen  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 screen  112 . In an exemplary embodiment, a point of contact between touch screen  112  and the user corresponds to a finger of the user. 
     Touch screen  112  may use LCD (liquid crystal display) technology, LPD (light emitting polymer display) technology, or LED (light emitting diode) technology, although other display technologies may be used in other embodiments. Touch screen  112  and display controller  156  may 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 screen  112 . In an exemplary embodiment, 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 screen  112  may have a video resolution in excess of 100 dpi. In some embodiments, the touch screen has a video resolution of approximately 160 dpi. The user may make contact with touch screen  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 primarily 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  may include 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 may be a touch-sensitive surface that is separate from touch screen  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  may include 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  may also include one or more optical sensors  164 .  FIG. 1A  shows an optical sensor coupled to optical sensor controller  158  in I/O subsystem  106 . Optical sensor  164  may include charge-coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) phototransistors. Optical sensor  164  receives 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  164  may capture still images or video. In some embodiments, an optical sensor is located on the back of device  100 , opposite touch screen display  112  on the front of the device, so that the touch screen display may be used 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 may be obtained for videoconferencing while the user views the other video conference participants on the touch screen display. 
     Device  100  may also include one or more proximity sensors  166 .  FIG. 1A  shows proximity sensor  166  coupled to peripherals interface  118 . Alternately, proximity sensor  166  may be coupled to input controller  160  in I/O subsystem  106 . In some embodiments, the proximity sensor turns off and disables touch screen  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  may also include one or more accelerometers  168 .  FIG. 1A  shows accelerometer  168  coupled to peripherals interface  118 . Alternately, accelerometer  168  may be coupled to 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 , 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. 1A and 3 . 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 screen display  112 ; sensor state, including information obtained from the device&#39;s various sensors and input control devices  116 ; and location information concerning the device&#39;s location and/or attitude. 
     Operating system  126  (e.g., 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 on iPod (trademark of Apple Inc.) devices. 
     Contact/motion module  130  may detect contact with touch screen  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, such as determining if contact has occurred (e.g., detecting a finger-down event), 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, may include 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 may be applied to single contacts (e.g., one finger 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  may detect a gesture input by a user. Different gestures on the touch-sensitive surface have different contact patterns. Thus, a gesture may be 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. 
     Graphics module  132  includes various known software components for rendering and displaying graphics on touch screen  112  or other display, including components for changing the intensity 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 may be 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 . 
     Text input module  134 , which may be 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  may 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 may 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 may be 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 may be 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 screen  112 , display controller  156 , contact module  130 , graphics module  132 , and text input module  134 , contacts module  137  may be used 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 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 screen  112 , display controller  156 , contact module  130 , graphics module  132 , and text input module  134 , telephone module  138  may be used 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 may use any of a plurality of communications standards, protocols and technologies. 
     In conjunction with RF circuitry  108 , audio circuitry  110 , speaker  111 , microphone  113 , touch screen  112 , display controller  156 , optical sensor  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 screen  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 screen  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, 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 may 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, or IMPS). 
     In conjunction with RF circuitry  108 , touch screen  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 (sports devices); 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 screen  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, or delete a still image or video from memory  102 . 
     In conjunction with touch screen  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 screen  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 screen  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 screen  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 may be 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 screen  112 , display system controller  156 , contact module  130 , graphics module  132 , text input module  134 , and browser module  147 , the widget creator module  150  may be used by a user to create widgets (e.g., turning a user-specified portion of a web page into a widget). 
     In conjunction with touch screen  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 screen  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 screen  112  or on an external, connected display via external port  124 ). In some embodiments, device  100  may include the functionality of an MP3 player, such as an iPod (trademark of Apple Inc.). 
     In conjunction with touch screen  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 screen  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  may be used 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 screen  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 instructions that allow the user to access, browse, receive (e.g., by streaming and/or download), play back (e.g., on the touch screen or on an external, connected display 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 may be combined or otherwise re-arranged in various embodiments. In some embodiments, memory  102  may store a subset of the modules and data structures identified above. Furthermore, memory  102  may store 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  may be reduced. 
     The predefined set of functions that may be performed exclusively through a touch screen and/or a touchpad 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 may be displayed on device  100 . In such embodiments, the touchpad may be referred to as a “menu button.” In some other embodiments, the menu button may be a physical push button or other physical input control device instead of a touchpad. 
       FIG. 1B  is a block diagram illustrating exemplary components for event handling in accordance with some embodiments. In some embodiments, memory  102  (in  FIG. 1A ) or  370  ( FIG. 3 ) includes event sorter  170  (e.g., in operating system  126 ) and a respective application  136 - 1  (e.g., any of the aforementioned applications  137 - 151 ,  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  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  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  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  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 may 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 may be called the hit view, and the set of events that are recognized as proper inputs may be 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  may utilize or call data updater  176 , object updater  177  or GUI updater  178  to update the application internal state  192 . Alternatively, 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 may 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 may also include 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  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  112 , when a touch is detected on touch-sensitive display  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 may 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  176  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, e.g., coordinating mouse movement and mouse button presses with or without single or multiple keyboard presses or holds, user movements 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, which may be 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  112  in accordance with some embodiments. The touch screen may display one or more graphics within user interface (UI)  200 . In this embodiment, as well as others described below, a user may 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 may include 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 embodiments, inadvertent contact with a graphic may not select the graphic. For example, a swipe gesture that sweeps over an application icon may not select the corresponding application when the gesture corresponding to selection is a tap. 
     Device  100  may also include one or more physical buttons, such as “home” or menu button  204 . As described previously, menu button  204  may be used to navigate to any application  136  in a set of applications that may be executed on device  100 . Alternatively, in some embodiments, the menu button is implemented as a soft key in a GUI displayed on touch screen  112 . 
     In one embodiment, device  100  includes touch screen  112 , 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  may be 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 an alternative embodiment, device  100  also may accept verbal input for activation or deactivation of some functions through microphone  113 . 
       FIG. 3  is a block diagram of an exemplary multifunction device with a display and a touch-sensitive surface 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 (CPU&#39;s)  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  may 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 typically a touch screen display. I/O interface  330  also may include a keyboard and/or mouse (or other pointing device)  350  and touchpad  355 . Memory  370  includes high-speed random access memory, such as DRAM, SRAM, DDR RAM or other random access solid state memory devices; and may include 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  may optionally include 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 ), or a subset thereof. Furthermore, memory  370  may store additional programs, modules, and data structures not present in memory  102  of portable multifunction device  100 . For example, memory  370  of device  300  may store 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 ) may not store these modules. 
     Each of the above identified elements in  FIG. 3  may be 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 may be combined or otherwise re-arranged in various embodiments. In some embodiments, memory  370  may store a subset of the modules and data structures identified above. Furthermore, memory  370  may store additional modules and data structures not described above. 
     Attention is now directed towards embodiments of user interfaces (“UI”) that may be implemented on portable multifunction device  100 . 
       FIG. 4A  illustrates an exemplary user interface for a menu of applications on portable multifunction device  100  in accordance with some embodiments. Similar user interfaces may be 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:
           Phone  138 , which may include an indicator  414  of the number of missed calls or voicemail messages;   E-mail client  140 , which may include an indicator  410  of the number of unread e-mails;   Browser  147 ; and   Video and music player  152 , also referred to as iPod (trademark of Apple Inc.) module  152 ; and   
           Icons for other applications, such as:
           IM  141 ;   Image management  144 ;   Camera  143 ;   Weather  149 - 1 ;   Stocks  149 - 2 ;   Workout support  142 ;   Calendar  148 ;   Alarm clock  149 - 4 ;   Map  154 ;   Notes  153 ;   Settings  412 , which provides access to settings for device  100  and its various applications  136 ; and   Online video module  155 , also referred to as YouTube (trademark of Google Inc.) module  155 .   
               

       FIG. 4B  illustrates an exemplary user interface on a device (e.g., device  300 ,  FIG. 3 ) with a touch-sensitive surface  451  (e.g., a tablet or touchpad  355 ,  FIG. 3 ) that is separate from the display  450  (e.g., touch screen display  112 ; display  340 ,  FIG. 3 ). Although many of the examples which follow will be given with reference to inputs on touch screen display  112  (where the touch sensitive surface and the display are combined), in some embodiments, the device detects inputs on a touch-sensitive surface that is separate from the display, as shown in  FIG. 4B . In some embodiments the touch sensitive surface (e.g.,  451  in  FIG. 4B ) has a primary axis (e.g.,  452  in  FIG. 4B ) that corresponds to a primary axis (e.g.,  453  in  FIG. 4B ) on the display (e.g.,  450 ). In accordance with these embodiments, the device detects contacts (e.g.,  460  and  462  in  FIG. 4B ) with the touch-sensitive surface  451  at locations that correspond to respective locations on the display (e.g., in  FIG. 4B, 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. 4B ) are used by the device to manipulate the user interface on the display (e.g.,  450  in  FIG. 4B ) of the multifunction device when the touch-sensitive surface is separate from the display. It should be understood that similar methods may be used for other user interfaces described herein. 
     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 with a display and a touch-sensitive surface, such as device  300  or portable multifunction device  100 . 
       FIGS. 5A-5CC  illustrate exemplary user interfaces for controlling display of application windows in accordance with some embodiments. The user interfaces in these figures are used to illustrate the processes described below, including the processes in  FIGS. 6A-6C and 7A-7E . 
       FIG. 5A  illustrates multiple windows  502  displayed on touch-sensitive display  112  of device  100 . In some embodiments, each of windows  502  corresponds to a respective application (e.g., an application, an operating system feature that may be presented in a window, a computer program). For example, windows  502 - 1  and  502 - 4  correspond to a first application (“Application A”), window  502 - 2  corresponds to a second application (“Application B”), window  502 - 3  corresponds to a third application (“Application C”), and window  502 - 5  corresponds to a fourth application (“Application D”). 
     Windows  502  are displayed in a layer order (e.g., a front-to-back order, a z-order). For example, in  FIG. 5A , window  502 - 1  is in the frontmost position in the order, above the other windows  502 - 2  thru  502 - 5 ; window  502 - 1  is in the foreground. Window  502 - 2  is in the next position below in the order, followed by window  502 - 3  and  502 - 4 . Window  502 - 5  is in the lowest position in the order; window  502 - 5  is furthest to the back. 
     Gesture  504  is detected on touch-sensitive display  112 . Gesture  504  includes contacts  504 -A and  504 -B moving in direction  506 . Direction  506  corresponds to a horizontal rightward direction on touch-sensitive display  112 . In some embodiments, gesture  504  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  504 , window  502 - 1  moves in accordance with direction  506 ; window  502 - 1  moves in direction  506 . As window  502 - 1  moves in direction  506 , window  502 - 1  is moving off of display  112 , as shown in  FIG. 5B . Window  502 - 1  continues moving in direction  506  until window  502 - 1  has moved fully off or partially off (e.g., almost fully off, such as having a predefined pixel width or percentage of the window still displayed proximate to an edge of display  112 ) of display  112 , as shown in  FIG. 5C . In  FIG. 5C , with window  502 - 1  partially off of display  112  (or fully off of display  112 , not shown), window  502 - 2  becomes the frontmost window among the remaining windows  502 - 2  thru  502 - 5 . 
     While window  502 - 1  is still partially off of display  112  and window  502 - 2  is frontmost, gesture  508  is detected on touch-sensitive display  112 . Gesture  508  includes contacts  508 -A and  508 -B moving in direction  510 . Direction  510  corresponds to a horizontal rightward direction on touch-sensitive display  112 . In some embodiments, gesture  508  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  508 , window  502 - 2  moves in accordance with direction  510 ; window  502 - 2  moves in direction  510 , in a similar manner as window  502 - 1  moves in direction  506 . As window  502 - 2  moves in direction  510 , window  502 - 2  is moving off of display  112 . Window  502 - 2  continues moving in direction  510  until window  502 - 2  has moved fully or partially off of display  112 , as shown in  FIG. 5D . In  FIG. 5D , with windows  502 - 1  and  502 - 2  partially off of display  112  (or fully off of display  112 , not shown), window  502 - 3  becomes the frontmost window among the remaining windows  502 - 3  thru  502 - 5 . 
     While windows  502 - 1  and  502 - 2  are still partially off of display  112  and window  502 - 3  is frontmost, gesture  512  is detected on touch-sensitive display  112 . Gesture  512  includes contacts  512 -A and  512 -B moving in direction  514 . Direction  514  corresponds to a horizontal leftward direction on touch-sensitive display  112 ; direction  514  is opposite of direction  510  ( FIG. 5C ). In some embodiments, gesture  512  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  512 , window  502 - 2  moves in accordance with direction  514 ; window  502 - 2  moves in direction  514 . As window  502 - 2  moves in direction  514 , window  502 - 2  is moving back onto display  112 , as shown in  FIG. 5E . Window  502 - 2  continues moving in direction  514  until window  502 - 2  moves back into, and is redisplayed at, the position it had just prior to the detection of gesture  508 , as shown in  FIG. 5F . In  FIG. 5F , window  502 - 2  is the frontmost window among the remaining windows  502 - 2  thru  502 - 5 . 
     While window  502 - 1  is still partially off of display  112  and window  502 - 2  is frontmost, gesture  516  is detected on touch-sensitive display  112 . Gesture  516  includes contacts  516 -A and  516 -B moving in direction  515 . Direction  515  corresponds to a horizontal leftward direction on touch-sensitive display  112 ; direction  515  is opposite of direction  506  ( FIG. 5A ). In some embodiments, gesture  516  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  516 , window  502 - 1  moves in accordance with direction  515 ; window  502 - 1  moves in direction  515 . As window  502 - 1  moves in direction  515 , window  502 - 1  is moving back onto display  112 . Window  502 - 1  continues moving in direction  515  until window  502 - 1  moves back into, and is redisplayed at, the position it had just prior to the detection of gesture  504 , as shown in  FIG. 5G . In  FIG. 5G , window  502 - 1  is the frontmost window among windows  502  that are displayed on display  112 ; windows  502 - 1  thru  502 - 5  are displayed in the original layer order as depicted in  FIG. 5A . 
     In some embodiments, when a window  502  moves, an animation showing the movement may be displayed. For example,  FIG. 5B  depicts an instant in the animation of the movement of window  502 - 1  partially off of display  112 .  FIG. 5E  depicts an instant in the animation of the movement of window  502 - 2  back onto display  112 . For sake of brevity, respective instants in the movement of window  502 - 2  partially off of display  112  and the movement of window  502 - 1  back onto display  112  are not shown in the figures. 
       FIGS. 5A-5G  depict an example of embodiments where windows  502  move off of (fully or partially) and back onto display  112  one window at a time. In these embodiments, even if there are multiple windows corresponding to the same application, the multiple windows corresponding to the same application still move one at a time, one window moving per gesture. For example, in response to the detection of gesture  504 , just window  502 - 1  moved off of display  112  even though window  502 - 4  corresponds to the same Application A as window  502 - 1 . To move window  502 - 4  off of display  112 , the user would, after performing gesture  508  to move window  502 - 2  off of display  112 , perform a third gesture similar to gesture  508  to move window  502 - 3  off of display  112 , and then perform a fourth gesture similar to gesture  508  to move window  502 - 4  off of the display. 
     In some other embodiments, multiple windows corresponding to the same application move off of or back onto display  112  together, as opposed to one at a time.  FIG. 5H  illustrates windows  502 - 1  thru  502 - 5 , with the same layer order as depicted in  FIG. 5A .  FIG. 5H  shows gesture  518  being detected on touch-sensitive display  112 . Gesture  518  includes contacts  518 -A and  518 -B moving in direction  517 . Direction  517  corresponds to a horizontal rightward direction on touch-sensitive display  112 . In some embodiments, gesture  518  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  518 , windows  502 - 1  and  502 - 4  move together in accordance with direction  517 ; windows  502 - 1  and  502 - 4  move in direction  517 . As windows  502 - 1  and  502 - 4  move in direction  517 , windows  502 - 1  and  502 - 4  are moving off of display  112 , as shown in  FIG. 5I . Windows  502 - 1  and  502 - 4  continue moving in direction  517  until windows  502 - 1  and  502 - 4  have moved fully off (or partially off, not shown) of display  112 , as shown in  FIG. 5J . In  FIG. 5J , with windows  502 - 1  and  502 - 4  fully off of display  112 , window  502 - 2  becomes the frontmost window among the remaining windows  502 - 2 ,  502 - 3 , and  502 - 5 . Window  502 - 5 , with window  502 - 4  off of display  112 , becomes the next window below window  502 - 3 . 
     While windows  502 - 1  and  502 - 4  are still off of display  112  and window  502 - 2  is frontmost, gesture  520  is detected on touch-sensitive display  112  ( FIG. 5J ). Gesture  520  includes contacts  520 -A and  520 -B moving in direction  519 . Direction  519  corresponds to a horizontal rightward direction on touch-sensitive display  112 . In some embodiments, gesture  520  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  520 , window  502 - 2  moves in accordance with direction  519 ; window  502 - 2  moves in direction  519 , in a similar manner as windows  502 - 1  and  502 - 4  move in direction  517 . As window  502 - 2  moves in direction  519 , window  502 - 2  is moving off of display  112 . Window  502 - 2  continues moving in direction  517  until window  502 - 2  has moved fully off (or partially off, not shown) of display  112 , as shown in  FIG. 5K . In  FIG. 5K , with windows  502 - 1 ,  502 - 2 , and  502 - 4  fully off of display  112 , window  502 - 3  becomes the frontmost window among the remaining windows  502 - 3  and  502 - 5 . 
     While windows  502 - 1 ,  502 - 2 , and  502 - 4  are still off of display  112  and window  502 - 3  is frontmost, gesture  522  is detected on touch-sensitive display  112  ( FIG. 5K ). Gesture  522  includes contacts  522 -A and  522 -B moving in direction  523 . Direction  523  corresponds to a horizontal leftward direction on touch-sensitive display  112 ; direction  523  is opposite of direction  519  ( FIG. 5J ). In some embodiments, gesture  522  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  522 , window  502 - 2  moves in accordance with direction  523 ; window  502 - 2  moves in direction  523 . As window  502 - 2  moves in direction  523 , window  502 - 2  is moving back onto display  112 , as shown in  FIG. 5L . Window  502 - 2  continues moving in direction  523  until window  502 - 2  moves back into and is redisplayed at the position it had just prior to the detection of gesture  520 , as shown in  FIG. 5M . In  FIG. 5M , window  502 - 2  is the frontmost window among the remaining windows  502 - 2 ,  502 - 3 , and  502 - 5 . 
     While windows  502 - 1  and  502 - 4  are still off of display  112  and window  502 - 2  is frontmost, gesture  524  is detected on touch-sensitive display  112  ( FIG. 5M ). Gesture  524  includes contacts  524 -A and  524 -B moving in direction  525 . Direction  525  corresponds to a horizontal leftward direction on touch-sensitive display  112 ; direction  525  is opposite of direction  517  ( FIG. 5H ). In some embodiments, gesture  524  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  524 , windows  502 - 1  and  502 - 4  move together in accordance with direction  525 ; windows  502 - 1  and  502 - 4  move in direction  525 . As windows  502 - 1  and  502 - 4  move in direction  525 , windows  502 - 1  and  502 - 4  are moving back onto display  112 . Windows  502 - 1  and  502 - 4  continue moving in direction  525  until windows  502 - 1  and  502 - 4  have moved back into and are redisplayed at the positions they had just prior to the detection of gesture  518 , as shown in  FIG. 5N . In  FIG. 5N , window  502 - 1  is the frontmost window among windows  502  that are displayed on display  112  and window  502 - 4  is displayed between windows  502 - 3  and  502 - 5  in the layer order; windows  502 - 1  thru  502 - 5  are displayed in the original layer order as depicted in  FIG. 5H . 
     In some embodiments, when a window  502  moves, an animation showing the movement may be displayed. For example,  FIG. 5I  depicts an instant in the animation of the movement of windows  502 - 1  and  502 - 4  off of display  112 .  FIG. 5L  depicts an instant in the animation of the movement of window  502 - 2  back onto display  112 . For sake of brevity, respective instants in the movement of window  502 - 2  off of display  112  and the movement of windows  502 - 1  and  502 - 4  back onto display  112  are not shown in the figures. 
     In  FIG. 5N , when windows  502 - 1  and  502 - 4  move back onto display  112 , they resumed their respective positions in the original layer order as depicted in  FIG. 5H . Alternatively, in some embodiments, when multiple windows corresponding to the same application move back onto display  112 , the windows among these multiple windows that are further back in the layer order may “jump” ahead in the layer order, so that windows corresponding to the same redisplayed application have consecutive positions in the layer order at the front of the layer order. For example,  FIGS. 5O-5P  depicts an alternative response to the detection of gesture  524 .  FIG. 5O  depicts an instant in the movement of windows of  502 - 1  and  502 - 4 , in the alternative response, back onto display  112 . In  FIG. 5O , window  502 - 1  is displayed as moving into its original frontmost position in the layer order, while window  502 - 4  is displayed as moving into a position above windows  502 - 2  and  502 - 3 , and just below window  502 - 1 , in the layer order. In  FIG. 5P , which shows windows  502 - 1  and  502 - 4  redisplayed on display  112 , window  502 - 1  is redisplayed in the frontmost position in the layer order, and window  502 - 4  is displayed in the next position below. Windows  502 - 2  and  502 - 3  are partially obscured by window  502 - 4 , which “jumped” ahead in the layer order. 
     Although  FIGS. 5A-5P  depict gestures that move in horizontal directions (rightward or leftward), in some other embodiments, the gestures may move in vertical or diagonal directions, and the windows move in vertical or diagonal directions in response.  FIG. 5Q  depicts windows  502 - 1  thru  502 - 5  in the same layer order as depicted in  FIG. 5A . Gesture  526  is detected on touch-sensitive display  112 . Gesture  526  includes contacts  526 -A and  526 -B moving in direction  527 . Direction  527  corresponds to a vertical downward direction on touch-sensitive display  112 . In some embodiments, gesture  526  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  526 , window  502 - 1  moves in accordance with direction  527 . As window  502 - 1  moves in direction  527 , window  502 - 1  is moving off of display  112 , as shown in  FIG. 5R . Window  502 - 1  continues moving in direction  527  until window  502 - 1  has moved fully off (or partially off, not shown) of display  112 , as shown in  FIG. 5S . In  FIG. 5S , with window  502 - 1  off of display  112 , window  502 - 2  becomes the frontmost window among the remaining windows  502 - 2  thru  502 - 5 . 
     While window  502 - 1  is still off of display  112  and window  502 - 2  is frontmost, gesture  528  is detected on touch-sensitive display  112  ( FIG. 5S ). Gesture  528  includes contacts  528 -A and  528 -B moving in direction  530 . Direction  530  corresponds to a vertical upward direction on touch-sensitive display  112 ; direction  530  is opposite of direction  527 . In some embodiments, gesture  528  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  528 , window  502 - 1  moves in accordance with direction  530 . As window  502 - 1  moves in direction  530 , window  502 - 1  is moving back onto display  112 , as shown in  FIG. 5T . Window  502 - 1  continues moving in direction  530  until window  502 - 1  moves back into, and is redisplayed at, the position it had just prior to the detection of gesture  526 , as shown in  FIG. 5U . In  FIG. 5U , window  502 - 1  is the frontmost window among windows  502  that are displayed on display  112 ; windows  502 - 1  thru  502 - 5  are displayed in the original layer order as depicted in  FIG. 5A . 
       FIG. 5V  depicts windows  502 - 1  thru  502 - 5  in the same layer order as depicted in  FIG. 5A . Gesture  532  is detected on touch-sensitive display  112 . Gesture  532  includes contacts  532 -A and  532 -B moving in direction  534 . Direction  534  corresponds to a upward and rightward diagonal direction on touch-sensitive display  112 . In some embodiments, gesture  532  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  532 , window  502 - 1  moves in accordance with direction  534 . As window  502 - 1  moves in direction  534 , window  502 - 1  is moving off of display  112 , as shown in  FIG. 5W . Window  502 - 1  continues moving in direction  534  until window  502 - 1  has moved fully off (or partially off, not shown) of display  112 , as shown in  FIG. 5X . In  FIG. 5X , with window  502 - 1  off of display  112 , window  502 - 2  becomes the frontmost window among the remaining windows  502 - 2  thru  502 - 5 . 
     While window  502 - 1  is still off of display  112  and window  502 - 2  is frontmost, gesture  536  is detected on touch-sensitive display  112 . Gesture  536  includes contacts  536 -A and  536 -B moving in direction  538 . Direction  538  corresponds to a downward and leftward diagonal direction on touch-sensitive display  112 ; direction  538  is opposite of direction  534 . In some embodiments, gesture  536  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  536 , window  502 - 1  moves in accordance with direction  538 . As window  502 - 1  moves in direction  538 , window  502 - 1  is moving back onto display  112 , as shown in  FIG. 5Y . Window  502 - 1  continues moving in direction  538  until window  502 - 1  moves back into, and is redisplayed at, the position it had just prior to the detection of gesture  532 , as shown in  FIG. 5Z . In  FIG. 5Z , window  502 - 1  is the frontmost window among windows  502  that are displayed on display  112 ; windows  502 - 1  thru  502 - 5  are displayed in the original layer order as depicted in  FIG. 5A . 
     While the embodiments illustrated in  FIGS. 5A-5Z  and described above show gestures being detected on touch-sensitive display  112  and windows  502  displayed on touch-sensitive display  112 , the embodiments illustrated in  FIGS. 5A-5Z  and described above apply in an analogous manner to embodiments where gestures are detected on a touch-sensitive surface that is not a touch-sensitive display. For example,  FIGS. 5AA-5CC  depict an analogous gesture and response to that as depicted in  FIGS. 5A-5C .  FIG. 5AA  illustrates touch-sensitive surface  451  and display  450  ( FIG. 4B ). Application windows  542 - 1  thru  542 - 5  are displayed on display  450 . Windows  542 - 1  thru  542 - 5  are analogous to windows  502 - 1  thru  502 - 5  ( FIG. 5A ). Window  542 - 1  is frontmost in the layer order, followed by windows  542 - 2 ,  542 - 3 ,  542 - 4 , and  542 - 5 . Windows  542 - 1  and  542 - 4  correspond to Application A. Window  542 - 2  correspond to Application B. Window  542 - 3  correspond to Application C. Window  542 - 5  correspond to Application D. 
     Gesture  544  is detected on touch-sensitive surface  451 . Gesture  544  includes contacts  544 -A and  544 -B moving in direction  546 . Direction  546  corresponds to a horizontal rightward direction on touch-sensitive surface  451 . Direction  546  corresponds to direction  550  on display  450 . In some embodiments, gesture  544  is a swipe, flick, or drag gesture. 
     In response to the detection of gesture  544 , window  542 - 1  moves in accordance with direction  546 ; window  542 - 1  moves in direction  550 . As window  542 - 1  moves in direction  550 , window  542 - 1  is moving off of display  450 , as shown in  FIG. 5BB . Window  542 - 1  continues moving in direction  550  until window  542 - 1  has moved partially off of display  450 , as shown in  FIG. 5CC  (or fully off of display  450 , not shown). In  FIG. 5CC , with window  542 - 1  partially off of display  450 , window  542 - 2  becomes the frontmost window among the remaining windows  542 - 2  thru  542 - 5 . 
       FIGS. 6A-6C  are flow diagrams illustrating a method  600  of controlling display of application windows in accordance with some embodiments. The method  600  is performed at an electronic device (e.g., device  300 ,  FIG. 3 , or portable multifunction device  100 ,  FIG. 1 ) with a display and a touch-sensitive surface. In some embodiments, the display is a touch screen display and the touch-sensitive surface is on the display. In some embodiments, the display is separate from the touch-sensitive surface. Some operations in method  600  may be combined and/or the order of some operations may be changed. 
     As described below, the method  600  provides an intuitive way to control display of application windows. The method reduces the cognitive burden on a user when controlling display of application windows, thereby creating a more efficient human-machine interface. For battery-operated electronic devices, enabling a user to control display of application windows faster and more efficiently conserves power and increases the time between battery charges. 
     The device displays a plurality of windows on the display (e.g., application windows) ( 602 ). The plurality of windows includes a first window for a first application displayed in a frontmost position on the display and a second window displayed in a lower position than the frontmost position. For example, in  FIG. 5A , windows  502 - 1  thru  502 - 5  are displayed on display  112 . Window  502 - 1  corresponds to Application A and is displayed in the frontmost position. Window  502 - 2  is displayed in the next lower position. As another example, in  FIG. 5AA , windows  542 - 1  thru  542 - 5  are displayed on display  450 . Window  542 - 1  corresponds to Application A and is displayed in the frontmost position. Window  542 - 2  is displayed in the next lower position. 
     In some embodiments, the second window is for a second application, distinct from the first application ( 604 ). For example, in  FIG. 5A , window  502 - 1  corresponds to Application A, and window  502 - 2  corresponds to Application B. 
     The device detects a first gesture moving in a first direction on the touch sensitive surface, the first direction on the touch sensitive surface corresponding to a first direction on the display ( 606 ). In  FIG. 5A , for example, gesture  504  is detected on touch-sensitive display  112 . Gesture  504  includes movement in direction  506 , which corresponds to direction  506  on display  112 . As another example, in  FIG. 5AA , gesture  544  is detected on touch-sensitive surface  451 . Gesture  544  includes movement in direction  546 , which corresponds to direction  550  on display  450 . 
     In some embodiments, the first gesture is a multifinger swipe gesture (e.g., a two-, three-, or four-finger drag (swipe) gesture) ( 608 ). For example, gestures  504  (FIG.  5 A) and  544  ( 5 AA) are multi-finger (each of these gestures have two concurrent contacts) swipe gestures. 
     In some embodiments, the first direction on the touch sensitive surface corresponds to a horizontal direction on the display ( 610 ). For example, a rightward (or substantially rightward) gesture on the touch sensitive surface moves the first window in a rightward direction across the display. For example, gesture  504  ( FIG. 5A ) moves in direction  506 , which is horizontal and rightward. In response to the detection of gesture  504 , window  502 - 1  moves in horizontal direction  506 . As another example, gesture  544  ( FIG. 5AA ) moves in direction  546 , which is horizontal and rightward. In response to the detection of gesture  544 , window  542 - 1  moves in direction  550 , which matches direction  546 . 
     In some embodiments, the first direction on the touch sensitive surface corresponds to a vertical direction on the display ( 612 ). For example, a downward (or substantially downward) gesture on the touch sensitive surface moves the first window in a downward direction across the display. For example, gesture  526  ( FIG. 5Q ) moves in direction  527 , which is vertical and downward. In response to the detection of gesture  526 , window  502 - 1  moves in vertical direction  527  ( FIG. 5R ). 
     In some embodiments, the first direction on the touch sensitive surface corresponds to a diagonal direction on the display ( 614 ). For example, an upward and rightward gesture on the touch sensitive surface moves the first window in an upward and rightward direction across the display. For example, gesture  532  ( FIG. 5V ) moves in direction  534 , which is upward and rightward on a diagonal. In response to the detection of gesture  532 , window  502 - 1  moves in diagonal direction  534  ( FIG. 5W ). 
     In response to detecting the first gesture moving in the first direction on the touch sensitive surface ( 616 ), the device moves the first window (e.g., displaying an animated movement of the first window) across the display in the first direction on the display until the first window is moved partially or fully off the display ( 618 ), and displays the second window in the frontmost position on the display ( 624 ). For example, in  FIGS. 5A-5C , in response to the detection of gesture  504 , window  502 - 1  moves across display  112  in direction  506  until window  501 - 1  is partially off of the display. Window  502 - 2  is displayed in the frontmost position, as shown in  FIG. 5C . In  FIGS. 5AA-5CC , in response to the detection of gesture  544  on touch-sensitive surface  451 , window  542 - 1  moves across display  450  in direction  550  until window  542 - 1  is partially off of display  450 . Window  542 - 2  is displayed in the frontmost position, as shown in  FIG. 5CC . 
     In some embodiments, the first window is moved partially off the display in response to detecting the first gesture moving in the first direction on the touch sensitive surface ( 620 ). For example, in  FIG. 5C , window  502 - 1  is moved partially off of display  112  in response to the detection of gesture  504 . 
     In some embodiments, the first window is moved fully off the display in response to detecting the first gesture moving in the first direction on the touch sensitive surface ( 624 ). For example, in  FIG. 5J , window  502 - 1  (along with window  502 - 4 ) is moved fully off of display  112  in response to the detection of gesture  518 . 
     In some embodiments, the first window is one of multiple windows for the first application ( 626 ). In response to detecting the first gesture moving in the first direction on the touch sensitive surface, the device moves the multiple windows (e.g., displaying an animated movement of the multiple windows) for the first application across the display in the first direction on the display until the multiple windows for the first application are moved partially or fully off the display ( 628 ). In some embodiments, in response to detecting the first gesture, all of the windows in the first application are moved partially off the display. In some embodiments, in response to detecting the first gesture, all of the windows in the first application are moved fully off the display. For example, in  FIG. 5H , windows  502 - 1  and  502 - 4  correspond to Application A. In response to the detection of gesture  518 , windows  502 - 1  and  502 - 4  are moved together in direction  517  until both are moved off of display  112 , as shown in  FIG. 5J . 
     In some embodiments, the plurality of windows has a layer order (i.e., a z-order or front-to-back order of the plurality of windows) ( 630 ). In response to detecting the first gesture moving in the first direction on the touch sensitive surface, the device maintains the layer order of the plurality of windows ( 632 ). For example, the first window is at the first (frontmost) position in the layer order and the second window is in the second (next-to-frontmost) position in the layer order just prior to detecting the first gesture. In response to detecting the first gesture (e.g., gesture  504 , the display in the first direction. The first window maintains its first position in the layer order even though the first window is no longer displayed (or is displayed only slightly at the edge of the display). Also in response to detecting the first gesture, the second window is displayed in the frontmost position on the display because the second window, with its second (next-to-frontmost) position in the layer order, has the top (frontmost) position in the layer order of the windows then being displayed. Subsequently, in response to the second gesture (e.g., gesture  516 ,  FIG. 5F ), the first window is moved back onto the display and is redisplayed in the frontmost position on the display because the first window maintains its first (frontmost) position in the layer order. 
     In some embodiments, after responding to the first gesture, while displaying the second window in the frontmost position on the display, the device detects a second gesture moving in a direction opposite the first direction on the touch sensitive surface ( 634 ). In response to detecting the second gesture moving in the direction opposite the first direction on the touch sensitive surface ( 636 ), the device moves ( 638 ) the first window (e.g., displaying an animated movement of the first window) across the display in a direction opposite the first direction on the display, and redisplays the first window in the frontmost position on the display ( 640 ). For example, after responding to gesture  504  ( FIG. 5A ), and while displaying window  502 - 2  in the frontmost position, gesture  516  is detected on touch-sensitive display  112 , as shown in  FIG. 5F . Gesture  516  moves in direction  515 , which is opposite of direction  506 . In response to the detection of gesture  516 , window  502 - 1  is moved in direction  515  and is redisplayed in the frontmost position, as shown in  FIG. 5G . 
     In some embodiments, in response to detecting the second gesture moving in the direction opposite the first direction on the touch sensitive surface, the device maintains the layer order of the plurality of windows ( 642 ). As noted above, in some embodiments, in response to the second gesture (e.g., gesture  516 ,  FIG. 5F ), the first window is moved back onto the display and is redisplayed in the frontmost position on the display because the first window maintains its first (frontmost) position in the layer order. 
     In some embodiments, the first window is one of multiple windows for the first application ( 644 ). In response to detecting the second gesture moving in the direction opposite the first direction on the touch sensitive surface, the device moves the multiple windows (e.g., displaying an animated movement of the multiple windows) for the first application across the display in the direction opposite the first direction on the display ( 646 ). In some embodiments, in response to detecting the second gesture, all of the windows in the first application are moved back onto the display, with the first window in the frontmost position. For example, in response to the detection of gesture  524  ( FIG. 5M ), windows  502 - 1  and  502 - 4  move in direction  525 , which is opposite of direction  517  ( FIG. 5H ). 
     It should be understood that the particular order in which the operations in  FIGS. 6A-6C  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 method  700  (e.g.,  FIGS. 7A-7E ) is also applicable in an analogous manner to method  600  described above with respect to  FIGS. 6A-6C . For example, the windows  502  described above with reference to method  600  may have one or more of the characteristics of the windows  502  described herein with reference to method  700 . For brevity, these details are not repeated here. 
       FIGS. 7A-7E  are flow diagrams illustrating a method  700  of controlling display of application windows in accordance with some embodiments. The method  700  is performed at an electronic device (e.g., device  300 ,  FIG. 3 , or portable multifunction device  100 ,  FIG. 1 ) with a display and a touch-sensitive surface. In some embodiments, the display is a touch screen display and the touch-sensitive surface is on the display. In some embodiments, the display is separate from the touch-sensitive surface. Some operations in method  700  may be combined and/or the order of some operations may be changed. 
     As described below, the method  700  provides an intuitive way to control display of application windows. The method reduces the cognitive burden on a user when controlling display of application windows, thereby creating a more efficient human-machine interface. For battery-operated electronic devices, enabling a user to control display of application windows faster and more efficiently conserves power and increases the time between battery charges. 
     The device displays a plurality of windows on the display (e.g., application windows) ( 702 ). The plurality of windows includes a first window for a first application displayed in a frontmost position on the display; a second window for a second application, distinct from the first application, displayed in a second position lower than the frontmost position; and a third window for a third application, distinct from the first application and the second application, displayed in a third position lower than the second position. For example, in  FIG. 5A , windows  502 - 1 ,  502 - 2 , and  502 - 3  are displayed on display  112 . Window  502 - 1  is displayed in the frontmost position and corresponds to Application A. Window  502 - 2  is displayed in a position lower than window  502 - 1  and corresponds to Application B. Window  502 - 3  is displayed in a position lower than window  502 - 2  and corresponds to Application C. 
     The device detects a first gesture moving in a first direction on the touch sensitive surface, the first direction on the touch sensitive surface corresponding to a first direction on the display ( 704 ). In  FIG. 5A , for example, gesture  504  is detected on touch-sensitive display  112 . Gesture  504  includes movement in direction  506 , which corresponds to direction  506  on display  112 . 
     In some embodiments, the first direction on the touch sensitive surface corresponds to a horizontal direction on the display ( 706 ). For example, a rightward (or substantially rightward) gesture on the touch sensitive surface moves the first window in a rightward direction across the display. For example, gesture  504  ( FIG. 5A ) moves in direction  506 , which is horizontal and rightward. In response to the detection of gesture  504 , window  502 - 1  moves in horizontal direction  506 . 
     In some embodiments, the first direction on the touch sensitive surface corresponds to a vertical direction on the display ( 708 ). For example, a downward (or substantially downward) gesture on the touch sensitive surface moves the first window in a downward direction across the display. For example, gesture  526  ( FIG. 5Q ) moves in direction  527 , which is vertical and downward. In response to the detection of gesture  526 , window  502 - 1  moves in vertical direction  527  ( FIG. 5R ). 
     In some embodiments, the first direction on the touch sensitive surface corresponds to a diagonal direction on the display ( 710 ). For example, an upward and rightward gesture on the touch sensitive surface moves the first window in an upward and rightward direction across the display. For example, gesture  532  ( FIG. 5V ) moves in direction  534 , which is upward and rightward on a diagonal. In response to the detection of gesture  532 , window  502 - 1  moves in diagonal direction  534  ( FIG. 5W ). 
     In some embodiments, in response to detecting the first gesture moving in the first direction on the touch sensitive surface ( 712 ), the device moves the first window (e.g., displaying an animated movement of the first window) across the display in the first direction on the display until the first window is moved partially or fully off the display ( 714 ), and displays the second window in the frontmost position on the display ( 716 ). For example, in  FIGS. 5A-5C , in response to the detection of gesture  504 , window  502 - 1  moves across display  112  in direction  506  until window  502 - 1  is partially off of the display. Window  502 - 2  is displayed in the frontmost position, as shown in  FIG. 5C . 
     In some embodiments, the first window is one of multiple windows for the first application ( 718 ). In response to detecting the first gesture moving in the first direction on the touch sensitive surface, the device moves the multiple windows (e.g., displaying an animated movement of the multiple windows) for the first application across the display in the first direction on the display until the multiple windows for the first application are moved partially or fully off the display ( 720 ). In some embodiments, in response to detecting the first gesture, all of the windows in the first application are moved partially off the display (e.g., almost fully off, such as having a predefined pixel width or percentage of the window still displayed proximate to an edge of display  112 ). In some embodiments, in response to detecting the first gesture, all of the windows in the first application are moved fully off the display. For example, windows  502 - 1  and  502 - 4  correspond to Application A, as shown in  FIG. 5H . In response to the detection of gesture  518 , windows  502 - 1  and  502 - 4  are moved together in direction  517  until both are moved off of display  112 , as shown in  FIG. 5J . 
     In some embodiments, the plurality of windows has a layer order (i.e., a z-order or front-to-back order of the plurality of windows) ( 722 ). In response to detecting the first gesture moving in the first direction on the touch sensitive surface, the device maintains the layer order of the plurality of windows ( 724 ). For example, the first window is at the first (frontmost) position in the layer order, the second window is in the second (next-to-frontmost) position in the layer order, and the third window is in the third (next-to-second) position in the layer order just prior to detecting the first gesture. In response to detecting the first gesture (e.g., gesture  504 ,  FIG. 5A ), the first window is moved off the display in the first direction. The first window maintains its first position in the layer order even though the first window is no longer displayed (or is displayed only slightly at the edge of the display). Also in response to detecting the first gesture, the second window is displayed in the frontmost position on the display because the second window, with its second (next-to-frontmost) position in the layer order, has the top (frontmost) position in the layer order of the windows then being displayed. In response to detecting the second gesture (e.g., gesture  508 ,  FIG. 5C ), the second window is moved off the display in the first direction. The first and second windows maintain their respective positions in the layer order even though the first window and the second window are no longer displayed (or are displayed only slightly at the edge of the display). Also in response to detecting the second gesture, the third window is displayed in the frontmost position on the display because the third window, with its third (next-to-second) position in the layer order, has the top (frontmost) position in the layer order of the windows then being displayed. Subsequently, in response to the third gesture (e.g., gesture  512 ,  FIG. 5D ), the second window is moved back onto the display and is redisplayed in the frontmost position on the display because the second window, with its second (next-to-frontmost) position in the layer order, has the top (frontmost) position in the layer order of the windows then being displayed. Subsequently, in response to the fourth gesture (e.g., gesture  516 ,  FIG. 5F ), the first window is moved back onto the display and is redisplayed in the frontmost position on the display because the first window, with its first (frontmost) position in the layer order, has the top (frontmost) position in the layer order of the windows then being displayed. 
     In some embodiments, each gesture moving in a first direction on the touch sensitive surface results in the currently displayed window with the frontmost position in the layer order being moved off the display in the first direction. In some embodiments, each gesture moving in the first direction on the touch sensitive surface results in the currently displayed window with the frontmost position in the layer order, as well other windows in the same application as the currently displayed window with the frontmost position in the layer order, being moved off the display in the first direction (e.g., as shown in  FIGS. 5H-5J ). 
     Conversely, in some embodiments, each gesture moving in a direction opposite the first direction on the touch sensitive surface results in redisplay of the window that was most recently moved off the display in the first direction in response to the most recent gesture in the first direction, with the redisplayed window appearing at a frontmost position on the display. In some embodiments, each gesture moving in the direction opposite the first direction on the touch sensitive surface also results in redisplay of other windows in the same application. In some embodiments, these other windows in the same application are redisplayed according to their original locations in the layer order, thereby maintaining the layer order (e.g., as shown in  FIGS. 5M-5N ). In some other embodiments, these other windows are redisplayed immediately below the redisplayed window at the frontmost position on the display, which may move these other windows in the same application frontward in the layer order (e.g., as shown in  FIGS. 5M, 5O-5P ). 
     After responding to the first gesture, while displaying the second window in the frontmost position on the display, the device detects a second gesture moving in the first direction on the touch sensitive surface ( 726 ). For example, after responding to gesture  504  ( FIG. 5A ), and while displaying window  502 - 2  in the frontmost position, gesture  508  is detected on touch-sensitive display  112 , as shown in  FIG. 5C . Gesture  508  moves in direction  510 , which is the same as direction  506 . 
     In response to detecting the second gesture moving in the first direction on the touch sensitive surface ( 728 ), the device moves the second window (e.g., displaying an animated movement of the first window) across the display in the first direction on the display until the second window is moved partially or fully off the display ( 730 ), and displays the third window in the frontmost position on the display ( 732 ). For example, in  FIGS. 5C-5D , in response to the detection of gesture  508 , window  502 - 2  moves across display  112  in direction  510  until window  502 - 2  is partially off of the display. Window  502 - 3  is displayed in the frontmost position, as shown in  FIG. 5D . 
     In some embodiments, the first window is moved partially off the display in response to detecting the first gesture moving in the first direction on the touch sensitive surface, and the second window is moved partially off the display in response to detecting the second gesture moving in the first direction on the touch sensitive surface ( 734 ). For example, in  FIG. 5C , window  502 - 1  is moved partially off of display  112  in response to the detection of gesture  504 . In  FIG. 5D , window  502 - 2  is moved partially off of display  112  in response to the detection of gesture  508 . 
     In some embodiments, the first window is moved fully off the display in response to detecting the first gesture moving in the first direction on the touch sensitive surface, and the second window is moved fully off the display in response to detecting the second gesture moving in the first direction on the touch sensitive surface ( 736 ). For example, in  FIG. 5J , window  502 - 1  (along with window  502 - 4 ) is moved fully off of display  112  in response to the detection of gesture  518 . In  FIG. 5K , window  502 - 2  is moved fully off of display  112  in response to the detection of gesture  520 . 
     In some embodiments, the second window is one of multiple windows for the second application ( 738 ). In response to detecting the second gesture moving in the first direction on the touch sensitive surface, the device moves the multiple windows (e.g., displaying an animated movement of the multiple windows) for the second application across the display in the first direction on the display until the multiple windows for the second application are moved partially or fully off the display ( 740 ). In some embodiments, in response to detecting the second gesture, all of the windows in the second application are moved partially off the display (e.g., almost fully off, such as having a predefined pixel width or percentage of the window still displayed proximate to an edge of display  112 ). In some embodiments, in response to detecting the second gesture, all of the windows in the second application are moved fully off the display. For example, in  FIG. 5J-5K , if there were additional windows  502  corresponding to Application B displayed on display  112  (not shown), in response to the detection of gesture  520 , the additional windows corresponding to Application B would be moved together with window  502 - 2  in direction  519  until the additional windows corresponding to Application B and window  502 - 2  were moved fully or partially off display  112 . 
     After responding to the second gesture, while displaying the third window in the frontmost position on the display, the device detects a third gesture moving in a direction opposite the first direction on the touch sensitive surface ( 742 ). For example, after responding to gesture  508  ( FIG. 5C ), and while displaying window  502 - 3  in the frontmost position, gesture  512  is detected on touch-sensitive display  112 , as shown in  FIG. 5D . Gesture  512  moves in direction  514 , which is opposite of direction  510 . 
     In response to detecting the third gesture moving in the direction opposite the first direction on the touch sensitive surface ( 744 ), the device moves the second window (e.g., displaying an animated movement of the second window) across the display in a direction opposite the first direction on the display ( 746 ), and redisplays the second window in the frontmost position on the display ( 748 ). For example, in  FIGS. 5D-5F , in response to the detection of gesture  512 , window  502 - 2  moves across display  112  in direction  514  and is redisplayed in the frontmost position, as shown in  FIG. 5F . 
     In some embodiments, the second window is one of multiple windows for the second application ( 750 ). In response to detecting the third gesture moving in the direction opposite the first direction on the touch sensitive surface, the device moves the multiple windows (e.g., displaying an animated movement of the multiple windows) for the second application across the display in the direction opposite the first direction on the display ( 752 ). In some embodiments, in response to detecting the third gesture, all of the windows in the second application are moved back onto the display, with the second window in the frontmost position. For example, in  FIG. 5K-5M , if there were additional windows  502  corresponding to Application B (not shown) that were moved partially or fully off of display  112  in response to the detection of gesture  520 , in response to the detection of gesture  522 , the additional windows corresponding to Application B would be moved together with window  502 - 2  in direction  523  (which is opposite of direction  519 ) until the additional windows corresponding to Application B and window  502 - 2  are moved back onto display  112  and redisplayed on display  112 . 
     After responding to the third gesture, while displaying the second window in the frontmost position on the display, the device detects a fourth gesture moving in the direction opposite the first direction on the touch sensitive surface ( 754 ). For example, after responding to gesture  512  ( FIG. 5D ), and while displaying window  502 - 2  in the frontmost position, gesture  516  is detected on touch-sensitive display  112 , as shown in  FIG. 5F . Gesture  516  moves in direction  515 , which is opposite of direction  506 . 
     In some embodiments, the first gesture, the second gesture, the third gesture, and the fourth gesture are multifinger swipe gestures (e.g., a two-, three-, or four-finger drag (swipe) gestures) ( 756 ). For example, gestures  504 ,  508 ,  512 ,  516  are multi-finger swipe gestures. 
     In response to detecting the fourth gesture moving in the direction opposite the first direction on the touch sensitive surface ( 758 ), the device moves the first window (e.g., displaying an animated movement of the first window) across the display in a direction opposite the first direction on the display ( 760 ), and redisplays the first window in the frontmost position on the display ( 762 ). For example, in  FIGS. 5F-5G , in response to the detection of gesture  516 , window  502 - 1  moves across display  112  in direction  515  and is redisplayed in the frontmost position, as shown in  FIG. 5G . 
     In some embodiments, the first window is one of multiple windows for the first application ( 764 ). In response to detecting the fourth gesture moving in the direction opposite the first direction on the touch sensitive surface, the device moves the multiple windows (e.g., displaying an animated movement of the multiple windows) for the first application across the display in the direction opposite the first direction on the display ( 766 ). In some embodiments, in response to detecting the fourth gesture, all of the windows in the first application are moved back onto the display, with the first window in the frontmost position. For example, in response to the detection of gesture  524 , windows  502 - 1  and  502 - 4  are moved together in direction  525  (which is opposite of direction  517 ) until both are moved back onto display  112  and redisplayed on display  112 , as shown in  FIGS. 5M-5N . 
     It should be understood that the particular order in which the operations in  FIGS. 7A-7E  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 method  600  (e.g.,  FIGS. 6A-6C ) is also applicable in an analogous manner to method  700  described above with respect to  FIGS. 7A-7E . For example, the windows  502  described above with reference to method  700  may have one or more of the characteristics of the windows  502  described herein with reference to method  600 . For brevity, these details are not repeated here. 
     In accordance with some embodiments,  FIG. 8  shows a functional block diagram of an electronic device  800  configured in accordance with the principles of the invention as described above. The functional blocks of the device may be implemented by hardware, software, or a combination of hardware and software to carry out the principles of the invention. It is understood by persons of skill in the art that the functional blocks described in  FIG. 8  may be combined or separated into sub-blocks to implement the principles of the invention as described above. Therefore, the description herein may support any possible combination or separation or further definition of the functional blocks described herein. 
     As shown in  FIG. 8 , in some embodiments, an electronic device  800  includes a display unit  802  configured to display a plurality of windows on the display unit  802 , the plurality of windows including a first window for a first application displayed in a frontmost position on the display unit  802  and a second window displayed in a lower position than the frontmost position; a touch-sensitive surface unit  804  configured to receive gestures; and a processing unit  806  coupled to the display unit  802  and the touch-sensitive surface unit  804 . In some embodiments, the processing unit  806  includes a detecting unit  808 , a moving unit  810 , a display enabling unit  812 , and a maintaining unit  814 . 
     The processing unit  806  is configured to: detect a first gesture moving in a first direction on the touch sensitive surface unit  804 , the first direction on the touch sensitive surface unit  804  corresponding to a first direction on the display unit  802  (e.g., with the detecting unit  808 ); and, in response to detecting the first gesture moving in the first direction on the touch sensitive surface unit  804 : move the first window across the display unit  802  in the first direction on the display unit  802  until the first window is moved partially or fully off the display unit  802  (e.g., with the moving unit  810 ); and enable display of the second window in the frontmost position on the display unit  802  (e.g., with the display enabling unit  812 ). 
     In some embodiments, the first gesture is a multifinger swipe gesture. 
     In some embodiments, the first direction on the touch sensitive surface unit  804  corresponds to a horizontal direction on the display unit  802 . 
     In some embodiments, the first direction on the touch sensitive surface unit  804  corresponds to a vertical direction on the display unit  802 . 
     In some embodiments, the first direction on the touch sensitive surface unit  804  corresponds to a diagonal direction on the display unit  802 . 
     In some embodiments, the first window is moved partially off the display unit  802  in response to detecting the first gesture moving in the first direction on the touch sensitive surface unit  804 . 
     In some embodiments, the first window is moved fully off the display unit  802  in response to detecting the first gesture moving in the first direction on the touch sensitive surface unit  804 . 
     In some embodiments, the second window is for a second application, distinct from the first application. 
     In some embodiments, the first window is one of multiple windows for the first application, and the processing unit  806  is configured to: in response to detecting the first gesture moving in the first direction on the touch sensitive surface unit  804 : move the multiple windows for the first application across the display unit  802  in the first direction on the display unit  802  until the multiple windows for the first application are moved partially or fully off the display unit  802  (e.g., with the moving unit  810 ). 
     In some embodiments, the plurality of windows has a layer order, and the processing unit  806  is configured to: in response to detecting the first gesture moving in the first direction on the touch sensitive surface unit  804 : maintain the layer order of the plurality of windows (e.g., with the maintaining unit  814 ). 
     In some embodiments, the processing unit  806  is configured to: after responding to the first gesture, while displaying the second window in the frontmost position on the display unit  802 , detect a second gesture moving in a direction opposite the first direction on the touch sensitive surface unit  804  (e.g., with the detecting unit  808 ); and, in response to detecting the second gesture moving in the direction opposite the first direction on the touch sensitive surface unit  804 : move the first window across the display unit  802  in a direction opposite the first direction on the display unit  802  (e.g., with the moving unit  810 ); and reenable display of the first window in the frontmost position on the display unit  802  (e.g., with the display enabling unit  812 ). 
     In some embodiments, the processing unit  806  is configured to: in response to detecting the second gesture moving in the direction opposite the first direction on the touch sensitive surface unit  804 : maintain the layer order of the plurality of windows (e.g., with the maintaining unit  814 ). 
     In some embodiments, the first window is one of multiple windows for the first application, and the processing unit  806  is configured to: in response to detecting the second gesture moving in the direction opposite the first direction on the touch sensitive surface unit  804 : move the multiple windows for the first application across the display unit  802  in the direction opposite the first direction on the display unit  802  (e.g., with the moving unit  810 ). 
     As shown in  FIG. 8 , in some embodiments, an electronic device  800  includes a display unit  802  configured to display a plurality of windows on the display unit  802 , the plurality of windows including: a first window for a first application displayed in a frontmost position on the display unit  802 ; a second window for a second application, distinct from the first application, displayed in a second position lower than the frontmost position; and a third window for a third application, distinct from the first application and the second application, displayed in a third position lower than the second position; a touch-sensitive surface unit  804  configured to receive gestures; and a processing unit  806  coupled to the display unit  802  and the touch-sensitive surface unit  804 . In some embodiments, the processing unit  806  includes a detecting unit  808 , a moving unit  810 , a display enabling unit  812 , and a maintaining unit  814 . 
     The processing unit  806  is configured to: detect a first gesture moving in a first direction on the touch sensitive surface unit  804 , the first direction on the touch sensitive surface unit  804  corresponding to a first direction on the display unit  802  (e.g., with the detecting unit  808 ); in response to detecting the first gesture moving in the first direction on the touch sensitive surface unit  804 : move the first window across the display unit  802  in the first direction on the display unit  802  until the first window is moved partially or fully off the display unit  802  (e.g., with the moving unit  810 ); and enable display of the second window in the frontmost position on the display unit  802  (e.g., with the display enabling unit  812 ); after responding to the first gesture, while displaying the second window in the frontmost position on the display unit  802 , detect a second gesture moving in the first direction on the touch sensitive surface unit  804  (e.g., with the detecting unit  808 ); in response to detecting the second gesture moving in the first direction on the touch sensitive surface unit  804 : move the second window across the display unit  802  in the first direction on the display unit  802  until the second window is moved partially or fully off the display unit  802  (e.g., with the moving unit  810 ); and enable display of the third window in the frontmost position on the display unit  802  (e.g., with the display enabling unit  812 ); after responding to the second gesture, while displaying the third window in the frontmost position on the display unit  802 , detect a third gesture moving in a direction opposite the first direction on the touch sensitive surface unit  804  (e.g., with the detecting unit  808 ); in response to detecting the third gesture moving in the direction opposite the first direction on the touch sensitive surface unit  804 : move the second window across the display unit  802  in a direction opposite the first direction on the display unit  802  (e.g., with the moving unit  810 ); and reenable display of the second window in the frontmost position on the display unit  802  (e.g., with the display enabling unit  812 ); after responding to the third gesture, while displaying the second window in the frontmost position on the display unit  802 , detect a fourth gesture moving in the direction opposite the first direction on the touch sensitive surface unit  804  (e.g., with the detecting unit  808 ); and, in response to detecting the fourth gesture moving in the direction opposite the first direction on the touch sensitive surface unit  804 : move the first window across the display unit  802  in a direction opposite the first direction on the display unit  802  (e.g., with the moving unit  810 ); and reenable display of the first window in the frontmost position on the display unit  802  (e.g., with the display enabling unit  812 ). 
     In some embodiments, the first gesture, the second gesture, the third gesture, and the fourth gesture are multifinger swipe gestures. 
     In some embodiments, the first direction on the touch sensitive surface unit  804  corresponds to a horizontal direction on the display unit  802 . 
     In some embodiments, the first direction on the touch sensitive surface unit  804  corresponds to a vertical direction on the display unit  802 . 
     In some embodiments, the first direction on the touch sensitive surface unit  804  corresponds to a diagonal direction on the display unit  802 . 
     In some embodiments, the first window is moved partially off the display unit  802  in response to detecting the first gesture moving in the first direction on the touch sensitive surface unit  804  and the second window is moved partially off the display unit  802  in response to detecting the second gesture moving in the first direction on the touch sensitive surface unit  804 . 
     In some embodiments, the first window is moved fully off the display unit  802  in response to detecting the first gesture moving in the first direction on the touch sensitive surface unit  804  and the second window is moved fully off the display unit  802  in response to detecting the second gesture moving in the first direction on the touch sensitive surface unit  804 . 
     In some embodiments, the first window is one of multiple windows for the first application, and the processing unit  806  is configured to: in response to detecting the first gesture moving in the first direction on the touch sensitive surface unit  804 : move the multiple windows for the first application across the display unit  802  in the first direction on the display unit  802  until the multiple windows for the first application are moved partially or fully off the display unit  802  (e.g., with the moving unit  810 ). 
     In some embodiments, the second window is one of multiple windows for the second application, and the processing unit  806  is configured to: in response to detecting the second gesture moving in the first direction on the touch sensitive surface unit  804 : move the multiple windows for the second application across the display unit  802  in the first direction on the display unit  802  until the multiple windows for the second application are moved partially or fully off the display unit  802  (e.g., with the moving unit  810 ). 
     In some embodiments, the plurality of windows has a layer order, and the processing unit  806  is configured to: in response to detecting the first gesture moving in the first direction on the touch sensitive surface unit  804 : maintain the layer order of the plurality of windows (e.g., with the maintaining unit  814 ). 
     In some embodiments, the second window is one of multiple windows for the second application, and the processing unit  806  is configured to: in response to detecting the third gesture moving in the direction opposite the first direction on the touch sensitive surface unit  804 : move the multiple windows for the second application across the display unit  802  in the direction opposite the first direction on the display unit  802  (e.g., with the moving unit  810 ). 
     In some embodiments, the first window is one of multiple windows for the first application, and the processing unit  806  is configured to: in response to detecting the fourth gesture moving in the direction opposite the first direction on the touch sensitive surface unit  804 : move the multiple windows for the first application across the display unit  802  in the direction opposite the first direction on the display unit  802  (e.g., with the moving unit  810 ). 
     The operations in the information processing methods described above may be implemented by running one or more functional modules in information processing apparatus such as general purpose processors or application specific chips. These modules, combinations of these modules, and/or their combination with general hardware (e.g., as described above with respect to  FIGS. 1A and 3 ) are all included within the scope of protection of the invention. 
     The operations described above with reference to  FIGS. 6A-6C, 7A-7E  may be implemented by components depicted in  FIGS. 1A-1B . For example, detection operation  606 , moving operation  618 , and displaying operation  622  may be implemented by event sorter  170 , event recognizer  180 , and event handler  190 . 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  may utilize or call 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. 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. 1A-1B . 
     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 utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.

Metadata:
Filing Date: 20111229
Publication Date: 20190827
Grant Date: 20190827
Priority Date: 20111015
Inventors: LOUCH, JOHN O.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F2203/04808", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F9/451", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0488", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0488", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F9/451", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04808", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0488", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F2203/04808", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F9/451", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 48086854