PATENT DOCUMENT

Publication Number: US-9934066-B2
Application Number: US-201514727703-A
Country: US
Kind Code: B2

Title: Priority-based managing and suspension of window processes in a browser application

Abstract:
The method for managing a plurality of windows of a browser application on an electronic device includes assigning a priority level to each process, including the browser application, running on the device, and distributing computing resources based on priority level. In response to receiving an action to open a window, the browser application starts the execution of a process for opening the window, associates the process with the window, and assigns a priority level to the process associated with the window. The browser application then monitors an activity level of each process associated with its windows. If the activity level decreases, the browser application assigns the process with the decreased activity level to a lower priority level. If requested computing resources exceed a maximum threshold, a process is selected from the lowest priority level processes, and the selected process is suspended.

Claims:
What is claimed is: 
     
       1. A computer-implemented method for managing a plurality of windows of a browser application, comprising:
 at an electronic device having a plurality of computing resources and an operating system, the operating system:
 assigning a priority level to each of a plurality of processes running on the electronic device, one of the processes comprising a browser application; 
 for each of a plurality of browser windows of the browser application, in response to receiving an action to open the window of the browser application:
 starting execution of a process for opening the window, 
 associating the process with the window, and 
 assigning a priority level from a plurality of priority levels to the process associated with the window, 
 wherein for at least one priority level, a plurality of processes of different windows of the browser application are assigned to the same at least one priority level; 
 
 for the at least one priority level in which the plurality of processes of different windows are assigned to the same at least one priority level, assigning a timestamp to each of the plurality of processes, the timestamp representing a time of when the at least one priority level was assigned to the corresponding process; 
 distributing the computing resources among the processes running on the electronic device and the processes associated with the plurality of windows of the browser application based on the priority level of each process; 
 monitoring an activity level of each of the plurality of processes associated with the plurality of windows of the browser application, wherein the activity level includes at least one of a central processing unit (CPU) activity level, a user activity with respect to the window of the browser application, and an activity level of a daemon associated with the browser application; 
 in response to detecting a decrease in the activity level of one of the monitored processes, assigning the monitored process with the decreased activity level to a lower priority level; and 
 in response to detecting a total amount of all computing resources requested by the processes exceeding a maximum threshold of the electronic device, selecting a process from the processes associated with the plurality of windows of the browser application with a lowest priority level and having an earliest timestamp assigned when the selected process was assigned with the lowest priority level, and suspending the selected process. 
 
 
     
     
       2. The computer-implemented method of  claim 1 , wherein the browser application is configured to display a window in a foreground view and a plurality of windows in a background view, and the decrease in activity level of the monitored process comprises moving the window associated with the monitored process from the foreground view to the background view of the browser application. 
     
     
       3. The computer-implemented method of  claim 1 , wherein monitoring an activity level of a process associated with a window comprises monitoring user actions with content displayed within the window. 
     
     
       4. The computer-implemented method of  claim 3 , wherein the content displayed within the window comprises a web page, and a user action with the content comprises an action to browse links associated with the web page or to scroll the web page within the window. 
     
     
       5. The computer-implemented method of  claim 1 , further comprising: starting execution of a daemon; and linking the daemon with a process associated with a window of the browser application, wherein the monitored activity level of the linked process depends on an activity level of the daemon. 
     
     
       6. The computer-implemented method of  claim 5 , wherein the daemon comprises a media daemon, and the activity level of the daemon comprises a download and/or play activity of the media daemon. 
     
     
       7. The computer-implemented method of  claim 1 , wherein the action to open a window of the browser application comprises an action to open a tab window within the browser application. 
     
     
       8. The computer-implemented method of  claim 1 , wherein the detecting a decrease in activity level of one of the monitored processes comprises receiving no user action with the monitored process for a continuous time period that exceeds an inactive time threshold. 
     
     
       9. The computer-implemented method of  claim 1 , wherein the assigning the monitored process with the decreased activity level to a lower priority level is based on an amount of decrease in activity level of the monitored process. 
     
     
       10. The computer-implemented method of  claim 1 , wherein the plurality of priority levels includes a first tier of priority levels assigned to foreground processes of the plurality of processes, a second tier of priority levels assigned to background processes of the plurality of processes, and a third tier of priority levels assigned to processes of the plurality of processes tagged for suspension in response to detecting that the total amount of all computing resources requested by the processes exceeds the maximum threshold of the electronic device. 
     
     
       11. The computer-implemented method of  claim 1 , wherein detecting the total amount of all computing resources requested by the processes comprises determining amounts of memory usage, battery power, and processing capability of the CPU for the processes. 
     
     
       12. A computer-readable non-transitory storage medium storing instructions that, when executed, cause an operating system executed by a processor, at an electronic device having a plurality of computing resources, to:
 assign a priority level to each of a plurality of processes running on the electronic device, one of the processes comprising a browser application; 
 for each of a plurality of windows of the browser application, in response to receiving an action to open the window of the browser application:
 start execution of a process for opening the window, 
 associate the process with the window, and 
 assign a priority level from a plurality of priority levels to the process associated with the window, 
 wherein for at least one priority level, a plurality of processes of different windows of the browser application are assigned to the same a least one priority level; 
 
 for the at least one priority level in which the plurality of processes of different windows are assigned to the same at least one priority level, assigning a timestamp to each of the plurality of processes, the timestamp representing a time of when the at least one priority level was assigned to the corresponding process; 
 distribute the computing resources among the processes running on the electronic device and the processes associated with the plurality of windows of the browser application based on the priority level of each process; 
 monitor an activity level of each of the plurality of processes associated with the plurality of windows of the browser application, wherein the activity level includes at least one of a central processing unit (CPU) activity level, a user activity with respect to the window of the browser application, and an activity level of a daemon associated with the browser application; 
 in response to detecting a decrease in the activity level of one of the monitored processes, assign the monitored process with the decreased activity level to a lower priority level; and 
 in response to detecting a total amount of all computing resources requested by the processes exceeding a maximum threshold of the electronic device, select a process from the processes associated with the plurality of windows of the browser application with a lowest priority level and having an earliest timestamp assigned when the selected process was assigned with the lowest priority level, and suspending the selected process. 
 
     
     
       13. The storage medium of  claim 12 , wherein the browser application is configured to display a window in a foreground view and a plurality of windows in a background view, and the decrease in activity level of the monitored process comprises moving the window associated with the monitored process from the foreground view to the background view of the browser application. 
     
     
       14. The storage medium of  claim 12 , wherein monitoring an activity level of a process associated with a window comprises monitoring user actions with content displayed within the window. 
     
     
       15. The storage medium of  claim 14 , wherein the content displayed within the window comprises a web page, and a user action with the content comprises an action to browse links associated with the web page or to scroll the web page within the window. 
     
     
       16. The storage medium of  claim 12 , wherein the action to open a window of the browser application comprises an action to open a tab window within the browser application. 
     
     
       17. The storage medium of  claim 12 , wherein the stored instructions that, when executed, further cause a processor to: start execution of a daemon; and link the daemon with a process associated with a window of the browser application, and wherein the monitored activity level of the linked process depends on an activity level of the daemon. 
     
     
       18. The storage medium of  claim 17 , wherein the daemon comprises a media daemon, and the activity level of the daemon comprises a download and/or play activity of the media daemon. 
     
     
       19. The storage medium of  claim 12 , wherein the plurality of priority levels includes a first tier of priority levels assigned to foreground processes of the plurality of processes, a second tier of priority levels assigned to background processes of the plurality of processes, and a third tier of priority levels assigned to processes of the plurality of processes tagged for suspension in response to detecting that the total amount of all computing resources requested by the processes exceeds the maximum threshold of the electronic device. 
     
     
       20. The storage medium of  claim 12 , wherein detecting the total amount of all computing resources requested by the processes comprises determining amounts of memory usage, battery power, and processing capability of the CPU for the processes.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/006,204, filed Jun. 1, 2014, the content of which is incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure generally relates to a browser application managing and prioritizing separate window processes for each of its tabs or windows, and in particular, relates to priority levels associated with each window process based on the activity level of the corresponding tab or window. 
     BACKGROUND 
     A web browser application allows a user of a computing device to open multiple web pages simultaneously using multiple windows or tabs. If a user has multiple browser windows open, one or more of the open windows may be in the background view of the device display, rather than visibly been displayed in a foreground view. Despite being in the background view, these open windows still use computing resources of the device, since the browser application and its windows run as a single process on the device. In case the computer operating system of the device now requires additional computing resources, suspending background windows to free up resources would therefore require suspending the browser application and its foreground window. Thus, a monolithic browser application lacks the flexibility to adjust its demand on computing resources based on one or more of its background windows being inactive. 
     SUMMARY 
     A method for managing a plurality of windows of a browser application is disclosed. Each (browser) window is associated with a separate window process with each window process assigned to a priority level. The computer operating system maintains a process priority list ranking all running processes, including the window processes of the browser application, based on their priority level. Based on the activity level of each window process, the browser application monitors and reassigns each window process to a higher or lower priority level. The operating system uses the process priority list to select a process to be suspended if a shortage of computing resources occurs. In some embodiments, the process in the lowest priority level that has the earliest timestamp for being assigned to lowest priority level is selected for suspension. This methods allows for a more efficient manner of processing browser windows by individually managing separate processes for each browser window. The method allows for a browser window in background view to be suspended without suspending the browser window in the foreground view or the browser application itself. 
     The disclosed method for managing a plurality of windows of a browser application. The method includes that the computer operating system of an electronic device that has a plurality of computing resources assigns a priority level to each of a plurality of processes running on the electronic device. One of the processes includes a browser application. In response to receiving an action to open a window of the browser application, the browser application starts the execution of a process for opening the window and associates the process with the window. The browser application further assigns a priority level from a plurality of priority levels to the process associated with the window in response to receiving an action to open a window of the browser application. The assigned priority level relates to the priority level of the browser application. In the method, the computer operating system distributes the computing resources among the processes based on the priority level of each process. 
     The method further includes monitoring an activity level of each process associated with a window of the plurality of windows of the browser application. In response to detecting a decrease in the activity level of one of the monitored processes, the method includes assigning the monitored process with the decreased activity level to a lower priority level. In response to detecting a total amount of all computing resources requested by the processes exceeding a maximum threshold of the electronic device, a process is selected from the processes with the lowest priority level, and the selected process is suspended. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         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 on a device with a touch-sensitive surface that is separate from the display, in accordance with some embodiments. 
         FIGS. 5A and 5B  are a flow chart illustrating a method for managing a plurality of windows of a browser application, in accordance with some embodiments. 
         FIGS. 6A and 6B  are block diagrams illustrating a browser application, window processes of the browser application, and other modules of the device, in accordance with some embodiments. 
         FIG. 7  illustrates an example user interface for a browser application, according to some embodiments, in accordance with some embodiments. 
     
    
    
     The figures depict various embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein. 
     DETAILED DESCRIPTION 
     In embodiments described below, methods for managing a plurality of windows of a browser application are based on associating each window with a separate window process and assigning each window process to a priority level based on the activity level of the associated window. Processes, including the window processes of the browser application are ranked according to their corresponding priority level. This allows the computer operating system of the device to select a process from the lowest priority level to be suspended if computing resources are needed for other processes. In some embodiments, the browser application assigns the lowest priority level when a window process changes from the foreground to background view. This allows the computer operating system to suspend inactive background window process and more efficiently utilize its processing capabilities when running the browser application. 
     Exemplary Devices 
     Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the various described embodiments. However, it will be apparent to one of ordinary skill in the art that the various described embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, circuits, and networks have not been described in detail so as not to unnecessarily obscure aspects of the embodiments. 
     It will also be understood that, although the terms first, second, etc. are, in some instances, used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first contact could be termed a second contact, and, similarly, a second contact could be termed a first contact, without departing from the scope of the various described embodiments. The first contact and the second contact are both contacts, but they are not the same contact. 
     The terminology used in the description of the various described embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various described embodiments and the appended claims, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     As used herein, the term “if” is, optionally, construed to mean “when” or “upon” or “in response to determining” or “in response to detecting,” depending on the context. Similarly, the phrase “if it is determined” or “if [a stated condition or event] is detected” is, optionally, construed to mean “upon determining” or “in response to determining” or “upon detecting [the stated condition or event]” or “in response to detecting [the stated condition or event],” depending on the context. 
     Embodiments of electronic devices, user interfaces for such devices, and associated processes for using such devices are described. In some embodiments, the device is a portable communications device, such as a mobile telephone, that also contains other functions, such as PDA and/or music player functions. Exemplary embodiments of portable multifunction devices include, without limitation, the iPhone®, iPod Touch®, and iPad® devices from Apple Inc. of Cupertino, Calif. Other portable electronic devices, such as laptops or tablet computers with touch-sensitive surfaces (e.g., touch screen displays and/or touch pads), are, optionally, used. It should also be understood that, in some embodiments, the device is not a portable communications device, but is a desktop computer with a touch sensitive surface (e.g., a touch screen display and/or a 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 optionally includes one or more other physical user-interface devices, such as a physical keyboard, a mouse and/or a joystick. 
     The device typically supports a variety of applications, such as one or more of the following: a drawing application, a presentation application, a word processing application, a website creation application, a disk authoring application, a spreadsheet application, a gaming application, a telephone application, a video conferencing application, an e-mail application, an instant messaging application, a workout support application, a photo management application, a digital camera application, a digital video camera application, a web browsing application, a digital music player application, and/or a digital video player application. 
     The various applications that are executed on the device optionally use at least one common physical user-interface device, such as the touch-sensitive surface. One or more functions of the touch-sensitive surface as well as corresponding information displayed on the device are, optionally, adjusted and/or varied from one application to the next and/or within a respective application. In this way, a common physical architecture (such as the touch-sensitive surface) of the device optionally supports the variety of applications with user interfaces that are intuitive and transparent to the user. 
     Attention is now directed toward embodiments of portable devices with touch-sensitive displays.  FIG. 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 is sometimes known as or called a touch-sensitive display system. Device  100  includes memory  102  (which optionally includes 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  optionally includes one or more optical sensors  164 . Device  100  optionally includes one or more intensity sensors  165  for detecting intensity of contacts on device  100  (e.g., a touch sensitive surface such as touch-sensitive display system  112  of device  100 ). Device  100  optionally includes one or more tactile output generators  167  for generating tactile outputs on device  100  (e.g., generating tactile outputs on a touch-sensitive surface such as touch sensitive display system  112  of device  100  or touchpad  355  of device  300 ). These components optionally communicate over one or more communication buses or signal lines  103 . 
     As used in the specification and claims, the term “intensity” of a contact on a touch-sensitive surface refers to the force or pressure (force per unit area) of a contact (e.g., a finger contact) on the touch sensitive surface, or to a substitute (proxy) for the force or pressure of a contact on the touch sensitive surface. The intensity of a contact has a range of values that includes at least four distinct values and more typically includes hundreds of distinct values (e.g., at least 256). Intensity of a contact is, optionally, determined (or measured) using various approaches and various sensors or combinations of sensors. For example, one or more force sensors underneath or adjacent to the touch-sensitive surface are, optionally, used to measure force at various points on the touch-sensitive surface. In some implementations, force measurements from multiple force sensors are combined (e.g., a weighted average) to determine an estimated force of a contact. Similarly, a pressure sensitive tip of a stylus is, optionally, used to determine a pressure of the stylus on the touch-sensitive surface. Alternatively, the size of the contact area detected on the touch sensitive surface and/or changes thereto, the capacitance of the touch-sensitive surface proximate to the contact and/or changes thereto, and/or the resistance of the touch-sensitive surface proximate to the contact and/or changes thereto are, optionally, used as a substitute for the force or pressure of the contact on the touch-sensitive surface. In some implementations, the substitute measurements for contact force or pressure are used directly to determine whether an intensity threshold has been exceeded (e.g., the intensity threshold is described in units corresponding to the substitute measurements). In some implementations, the substitute measurements for contact force or pressure are converted to an estimated force or pressure and the estimated force or pressure is used to determine whether an intensity threshold has been exceeded (e.g., the intensity threshold is a pressure threshold measured in units of pressure). 
     As used in the specification and claims, the term “tactile output” refers to physical displacement of a device relative to a previous position of the device, physical displacement of a component (e.g., a touch-sensitive surface) of a device relative to another component (e.g., housing) of the device, or displacement of the component relative to a center of mass of the device that will be detected by a user with the user&#39;s sense of touch. For example, in situations where the device or the component of the device is in contact with a surface of a user that is sensitive to touch (e.g., a finger, palm, or other part of a user&#39;s hand), the tactile output generated by the physical displacement will be interpreted by the user as a tactile sensation corresponding to a perceived change in physical characteristics of the device or the component of the device. For example, movement of a touch-sensitive surface (e.g., a touch-sensitive display or trackpad) is, optionally, interpreted by the user as a “down click” or “up click” of a physical actuator button. In some cases, a user will feel a tactile sensation such as an “down click” or “up click” even when there is no movement of a physical actuator button associated with the touch-sensitive surface that is physically pressed (e.g., displaced) by the user&#39;s movements. As another example, movement of the touch-sensitive surface is, optionally, interpreted or sensed by the user as “roughness” of the touch-sensitive surface, even when there is no change in smoothness of the touch-sensitive surface. While such interpretations of touch by a user will be subject to the individualized sensory perceptions of the user, there are many sensory perceptions of touch that are common to a large majority of users. Thus, when a tactile output is described as corresponding to a particular sensory perception of a user (e.g., an “up click,” a “down click,” “roughness”), unless otherwise stated, the generated tactile output corresponds to physical displacement of the device or a component thereof that will generate the described sensory perception for a typical (or average) user. 
     It should be appreciated that device  100  is only one example of a portable multifunction device, and that device  100  optionally has more or fewer components than shown, optionally combines two or more components, or optionally has a different configuration or arrangement of the components. The various components shown in  FIG. 1A  are 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  optionally includes high-speed random access memory and optionally also includes non-volatile memory, such as one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state memory devices. Access to memory  102  by other components of device  100 , such as CPU  120  and the peripherals interface  118 , is, optionally, controlled by memory controller  122 . 
     Peripherals interface  118  can be used to couple input and output peripherals of the device to CPU  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  are, optionally, implemented on a single chip, such as chip  104 . In some other embodiments, they are, optionally, implemented on separate chips. 
     RF (radio frequency) circuitry  108  receives and sends RF signals, also called electromagnetic signals. RF circuitry  108  converts electrical signals to/from electromagnetic signals and communicates with communications networks and other communications devices via the electromagnetic signals. RF circuitry  108  optionally includes well-known circuitry for performing these functions, including but not limited to an antenna system, an RF transceiver, one or more amplifiers, a tuner, one or more oscillators, a digital signal processor, a CODEC chipset, a subscriber identity module (SIM) card, memory, and so forth. RF circuitry  108  optionally communicates with networks, such as the Internet, also referred to as the World Wide Web (WWW), an intranet and/or a wireless network, such as a cellular telephone network, a wireless local area network (LAN) and/or a metropolitan area network (MAN), and other devices by wireless communication. The wireless communication optionally uses any of a plurality of communications standards, protocols and technologies, including but not limited to Global System for Mobile Communications (GSM), Enhanced Data GSM Environment (EDGE), high-speed downlink packet access (HSDPA), high-speed uplink packet access (HSUPA), Evolution, Data-Only (EV-DO), HSPA, HSPA+, Dual-Cell HSPA (DC-HSPDA), long term evolution (LTE), near field communication (NFC), wideband code division multiple access (W-CDMA), code division multiple access (CDMA), time division multiple access (TDMA), Bluetooth, Wireless Fidelity (Wi-Fi) (e.g., IEEE 802.11a, IEEE 802.11b, IEEE 802.11g and/or IEEE 802.11n), 
     Audio circuitry  110 , speaker  111 , and microphone  113  provide an audio interface between a user and device  100 . Audio circuitry  110  receives audio data from peripherals interface  118 , converts the audio data to an electrical signal, and transmits the electrical signal to speaker  111 . Speaker  111  converts the electrical signal to human-audible sound waves. Audio circuitry  110  also receives electrical signals converted by microphone  113  from sound waves. Audio circuitry  110  converts the electrical signal to audio data and transmits the audio data to peripherals interface  118  for processing. Audio data is, optionally, retrieved from and/or transmitted to memory  102  and/or RF circuitry  108  by peripherals interface  118 . In some embodiments, audio circuitry  110  also includes a headset jack. 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  optionally includes display controller  156 , optical sensor controller  158 , intensity sensor controller  159 , haptic feedback controller  161  and one or more input controllers  160  for other input or control devices. The one or more input controllers  160  receive/send electrical signals from/to other input or control devices  116 . The other input control devices  116  optionally include physical buttons (e.g., push buttons, rocker buttons, etc.), dials, slider switches, joysticks, click wheels, and so forth. In some alternate embodiments, input controller(s)  160  are, optionally, coupled 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 optionally include an up/down button for volume control of speaker  111  and/or microphone  113 . The one or more buttons optionally include a push button. 
     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 optionally includes graphics, text, icons, video, and any combination thereof (collectively termed “graphics”). In some embodiments, some or all of the visual output corresponds to user-interface objects. 
     Touch 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  optionally uses LCD (liquid crystal display) technology, LPD (light emitting polymer display) technology, or LED (light emitting diode) technology, although other display technologies are used in other embodiments. Touch screen  112  and display controller  156  optionally detect contact and any movement or breaking thereof using any of a plurality of touch sensing technologies now known or later developed, including but not limited to capacitive, resistive, infrared, and surface acoustic wave technologies, as well as other proximity sensor arrays or other elements for determining one or more points of contact with touch 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  optionally has a video resolution in excess of 100 dpi. In some embodiments, the touch screen has a video resolution of approximately 160 dpi. The user optionally makes 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  optionally includes a touchpad (not shown) for activating or deactivating particular functions. In some embodiments, the touchpad is a touch-sensitive area of the device that, unlike the touch screen, does not display visual output. The touchpad is, optionally, a touch-sensitive surface that is separate from touch 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  optionally includes a power management system, one or more power sources (e.g., battery, alternating current (AC)), a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator (e.g., a light emitting diode (LED)) and any other components associated with the generation, management and distribution of power in portable devices. 
     Device  100  optionally also includes one or more optical sensors  164 .  FIG. 1A  shows an optical sensor coupled to optical sensor controller  158  in I/O subsystem  106 . Optical sensor  164  optionally includes 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  optionally captures 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 is enabled for use as a viewfinder for still and/or video image acquisition. In some embodiments, another optical sensor is located on the front of the device so that the user&#39;s image is, optionally, obtained for videoconferencing while the user views the other video conference participants on the touch screen display. 
     Device  100  optionally also includes one or more contact intensity sensors  165 .  FIG. 1A  shows a contact intensity sensor coupled to intensity sensor controller  159  in I/O subsystem  106 . Contact intensity sensor  165  optionally includes one or more piezoresistive strain gauges, capacitive force sensors, electric force sensors, piezoelectric force sensors, optical force sensors, capacitive touch-sensitive surfaces, or other intensity sensors (e.g., sensors used to measure the force (or pressure) of a contact on a touch sensitive surface). Contact intensity sensor  165  receives contact intensity information (e.g., pressure information or a proxy for pressure information) from the environment. In some embodiments, at least one contact intensity sensor is collocated with, or proximate to, a touch-sensitive surface (e.g., touch-sensitive display system  112 ). In some embodiments, at least one contact intensity sensor is located on the back of device  100 , opposite touch screen display  112  which is located on the front of device  100 . 
     Device  100  optionally also includes one or more proximity sensors  166 .  FIG. 1A  shows proximity sensor  166  coupled to peripherals interface  118 . Alternately, proximity sensor  166  is coupled to input controller  160  in 1/0 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  optionally also includes one or more tactile output generators  167 .  FIG. 1A  shows a tactile output generator coupled to haptic feedback controller  161  in I/O subsystem  106 . Tactile output generator  167  optionally includes one or more electroacoustic devices such as speakers or other audio components and/or electromechanical devices that convert energy into linear motion such as a motor, solenoid, electroactive polymer, piezoelectric actuator, electrostatic actuator, or other tactile output generating component (e.g., a component that converts electrical signals into tactile outputs on the device). Contact intensity sensor  165  receives tactile feedback generation instructions from haptic feedback module  133  and generates tactile outputs on device  100  that are capable of being sensed by a user of device  100 . In some embodiments, at least one tactile output generator is collocated with, or proximate to, a touch-sensitive surface (e.g., touch sensitive display system  112 ) and, optionally, generates a tactile output by moving the touch-sensitive surface vertically (e.g., in/out of a surface of device  100 ) or laterally (e.g., back and forth in the same plane as a surface of device  100 ). In some embodiments, at least one tactile output generator sensor is located on the back of device  100 , opposite touch screen display  112  which is located on the front of device  100 . 
     Device  100  optionally also includes one or more accelerometers  168 .  FIG. 1A  shows accelerometer  168  coupled to peripherals interface  118 . Alternately, accelerometer  168  is, optionally, 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  optionally detects 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 an intensity of the contact (e.g., the force or pressure of the contact or a substitute for the force or pressure of the contact), determining if there is movement of the contact and tracking the movement across the touch-sensitive surface (e.g., detecting one or more finger-dragging events), and determining if the contact has ceased (e.g., detecting a finger-up event or a break in contact). Contact/motion module  130  receives contact data from the touch-sensitive surface. Determining movement of the point of contact, which is represented by a series of contact data, optionally includes determining speed (magnitude), velocity (magnitude and direction), and/or an acceleration (a change in magnitude and/or direction) of the point of contact. These operations are, optionally, applied to single contacts (e.g., one finger contacts) or 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. 
     In some embodiments, contact/motion module  130  uses a set of one or more intensity thresholds to determine whether an operation has been performed by a user (e.g., to determine whether a user has “clicked” on an icon). In some embodiments at least a subset of the intensity thresholds are determined in accordance with software parameters (e.g., the intensity thresholds are not determined by the activation thresholds of particular physical actuators and can be adjusted without changing the physical hardware of device  100 ). For example, a mouse “click” threshold of a trackpad or touch screen display can be set to any of a large range of predefined thresholds values without changing the trackpad or touch screen display hardware. Additionally, in some implementations a user of the device is provided with software settings for adjusting one or more of the set of intensity thresholds (e.g., by adjusting individual intensity thresholds and/or by adjusting a plurality of intensity thresholds at once with a system-level click “intensity” parameter). 
     Contact/motion module  130  optionally detects a gesture input by a user. Different gestures on the touch-sensitive surface have different contact patterns (e.g., different motions, timings, and/or intensities of detected contacts). Thus, a gesture is, optionally, detected by detecting a particular contact pattern. For example, detecting a finger tap gesture includes detecting a finger-down event followed by detecting a finger-up (lift off) event at the same position (or substantially the same position) as the finger-down event (e.g., at the position of an icon). As another example, detecting a finger swipe gesture on the touch-sensitive surface includes detecting a finger-down event followed by detecting one or more finger-dragging events, and subsequently followed by detecting a finger-up (lift off) event. 
     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 visual impact (e.g., brightness, transparency, saturation, contrast or other visual property) of graphics that are displayed. As used herein, the term “graphics” includes any object that can be displayed to a user, including without limitation text, web pages, icons (such as user-interface objects including soft keys), digital images, videos, animations and the like. 
     In some embodiments, graphics module  132  stores data representing graphics to be used. Each graphic is, optionally, assigned a corresponding code. Graphics module  132  receives, from applications etc., one or more codes specifying graphics to be displayed along with, if necessary, coordinate data and other graphic property data, and then generates screen image data to output to display controller  156 . 
     Haptic feedback module  133  includes various software components for generating instructions used by tactile output generator(s)  167  to produce tactile outputs at one or more locations on device  100  in response to user interactions with device  100 . 
     Text input module  134 , which is, optionally, a component of graphics module  132 , provides soft keyboards for entering text in various applications (e.g., contacts  137 , e-mail  140 , IM  141 , browser  147 , and any other application that needs text input). 
     GPS module  135  determines the location of the device and provides this information for use in various applications (e.g., to telephone  138  for use in location-based dialing, to camera  143  as picture/video metadata, and to applications that provide location-based services such as weather widgets, local yellow page widgets, and map/navigation widgets). 
     Applications  136  optionally include the following modules (or sets of instructions), or a subset or superset thereof:
         contacts module  137  (sometimes called an address book or contact list);   telephone module  138 ;   video conferencing module  139 ;   e-mail client module  140 ;   instant messaging (IM) module  141 ;   workout support module  142 ;   camera module  143  for still and/or video images;   image management module  144 ;   browser module  147 ;   calendar module  148 ;   widget modules  149 , which optionally include one or more of: weather widget  149 - 1 , stocks widget  149 - 2 , calculator widget  149 - 3 , alarm clock widget  149 - 4 , dictionary widget  149 - 5 , and other widgets obtained by the user, as well as user created widgets  149 - 6 ;   widget creator module  150  for making user-created widgets  149 - 6 ;   search module  151 ;   video and music player module  152 , which is, optionally, made up of a video player module and a music player module;   notes module  153 ;   map module  154 ; and/or   online video module  155 .       

     Examples of other applications  136  that are, optionally, stored in memory  102  include other word processing applications, other image editing applications, drawing applications, presentation applications, JAVA-enabled applications, encryption, digital rights management, voice recognition, and voice replication. 
     In conjunction with touch screen  112 , display controller  156 , contact module  130 , graphics module  132 , and text input module  134 , contacts module  137  are, optionally, 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  are, optionally, 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 optionally uses any of a plurality of communications standards, protocols and technologies. 
     In conjunction with RF circuitry  108 , audio circuitry  110 , speaker  111 , microphone  113 , touch 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 optionally include graphics, photos, audio files, video files and/or other attachments as are supported in a MMS and/or an Enhanced Messaging Service (EMS). As used herein, “instant messaging” refers to both telephony-based messages (e.g., messages sent using SMS or MMS) and Internet-based messages (e.g., messages sent using XMPP, SIMPLE, 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 are, optionally, downloaded and used by a user (e.g., weather widget  149 - 1 , stocks widget  149 - 2 , calculator widget  149 - 3 , alarm clock widget  149 - 4 , and dictionary widget  149 - 5 ) or created by the user (e.g., user-created widget  149 - 6 ). In some embodiments, a widget includes an HTML (Hypertext Markup Language) file, a CSS (Cascading Style Sheets) file, and a JavaScript file. In some embodiments, a widget includes an XML (Extensible Markup Language) file and a JavaScript file (e.g., Yahoo! Widgets). 
     In conjunction with RF circuitry  108 , touch 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  are, optionally, 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  optionally includes 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  are, optionally, 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 are, optionally, combined or otherwise re-arranged in various embodiments. In some embodiments, memory  102  optionally stores a subset of the modules and data structures identified above. Furthermore, memory  102  optionally stores additional modules and data structures not described above. 
     In some embodiments, device  100  is a device where operation of a predefined set of functions on the device is performed exclusively through a touch screen and/or a touchpad. By using a touch screen and/or a touchpad as the primary input control device for operation of device  100 , the number of physical input control devices (such as push buttons, dials, and the like) on device  100  is, optionally, reduced. 
     The predefined set of functions that are performed exclusively through a touch screen and/or a touchpad optionally include navigation between user interfaces. In some embodiments, the touchpad, when touched by the user, navigates device  100  to a main, home, or root menu from any user interface that is displayed on device  100 . In such embodiments, a “menu button” is implemented using a touchpad. In some other embodiments, the menu button is a physical push button or other physical input control device instead of a touchpad. 
       FIG. 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 - 13 ,  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 optionally correspond to programmatic levels within a programmatic or view hierarchy of the application. For example, the lowest level view in which a touch is detected is, optionally, called the hit view, and the set of events that are recognized as proper inputs are, optionally, determined based, at least in part, on the hit view of the initial touch that begins a touch-based gesture. 
     Hit view determination module  172  receives information related to sub-events of a touch-based gesture. When an application has multiple views organized in a hierarchy, hit view determination module  172  identifies a hit view as the lowest view in the hierarchy which should handle the sub-event. In most circumstances, the hit view is the lowest level view in which an initiating sub-event occurs (i.e., the first sub-event in the sequence of sub-events that form an event or potential event). Once the hit view is identified by the hit view determination module, the hit view typically receives all sub-events related to the same touch or input source for which it was identified as the hit view. 
     Active event recognizer determination module  173  determines which view or views within a view hierarchy should receive a particular sequence of sub-events. In some embodiments, active event recognizer determination module  173  determines that only the hit view should receive a particular sequence of sub-events. In other embodiments, active event recognizer determination module  173  determines that all views that include the physical location of a sub-event are actively involved views, and therefore determines that all actively involved views should receive a particular sequence of sub-events. In other embodiments, even if touch sub-events were entirely confined to the area associated with one particular view, views higher in the hierarchy would still remain as actively involved views. 
     Event dispatcher module  174  dispatches the event information to an event recognizer (e.g., event recognizer  180 ). In embodiments including active event recognizer determination module  173 , event dispatcher module  174  delivers the event information to an event recognizer determined by active event recognizer determination module  173 . In some embodiments, event dispatcher module  174  stores in an event queue the event information, which is retrieved by a respective event receiver module  182 . 
     In some embodiments, operating system  126  includes event sorter  170 . Alternatively, application  136 - 1  includes event sorter  170 . In yet other embodiments, event sorter  170  is a stand-alone module, or a part of another module stored in memory  102 , such as contact/motion module  130 . 
     In some embodiments, application  136 - 1  includes a plurality of event handlers  190  and one or more application views  191 , each of which includes instructions for handling touch events that occur within a respective view of the application&#39;s user interface. Each application view  191  of the application  136 - 1  includes one or more event recognizers  180 . Typically, a respective application view  191  includes a plurality of event recognizers  180 . In other embodiments, one or more of event recognizers  180  are part of a separate module, such as a user interface kit (not shown) or a higher level object from which application  136 - 1  inherits methods and other properties. In some embodiments, a respective event handler  190  includes one or more of: data updater  176 , object updater  177 , GUI updater  178 , and/or event data  179  received from event sorter  170 . Event handler  190  optionally utilizes or calls data updater  176 , object updater  177  or GUI updater  178  to update the application internal state  192 . Alternatively, one or more of the application views  191  includes one or more respective event handlers  190 . Also, in some embodiments, one or more of data updater  176 , object updater  177 , and GUI updater  178  are included in a respective application view  191 . 
     A respective event recognizer  180  receives event information (e.g., event data  179 ) from event sorter  170 , and identifies an event from the event information. Event recognizer  180  includes event receiver  182  and event comparator  184 . In some embodiments, event recognizer  180  also includes at least a subset of: metadata  183 , and event delivery instructions  188  (which optionally include sub-event delivery instructions). 
     Event receiver  182  receives event information from event sorter  170 . The event information includes information about a sub-event, for example, a touch or a touch movement. Depending on the sub-event, the event information also includes additional information, such as location of the sub-event. When the sub-event concerns motion of a touch, the event information optionally also includes speed and direction of the sub-event. In some embodiments, events include rotation of the device from one orientation to another (e.g., from a portrait orientation to a landscape orientation, or vice versa), and the event information includes corresponding information about the current orientation (also called device attitude) of the device. 
     Event comparator  184  compares the event information to predefined event or sub-event definitions and, based on the comparison, determines an event or sub-event, or determines or updates the state of an event or sub-event. In some embodiments, event comparator  184  includes event definitions  186 . Event definitions  186  contain definitions of events (e.g., predefined sequences of sub-events), for example, event  1  ( 187 - 1 ), event  2  ( 187 - 2 ), and others. In some embodiments, sub-events in an event  187  include, for example, touch begin, touch end, touch movement, touch cancellation, and multiple touching. In one example, the definition for event  1  ( 187 - 1 ) is a double tap on a displayed object. The double tap, for example, comprises a first touch (touch begin) on the displayed object for a predetermined phase, a first lift-off (touch end) for a predetermined phase, a second touch (touch begin) on the displayed object for a predetermined phase, and a second lift-off (touch end) for a predetermined phase. In another example, the definition for event  2  ( 187 - 2 ) is a dragging on a displayed object. The dragging, for example, comprises a touch (or contact) on the displayed object for a predetermined phase, a movement of the touch across touch sensitive display  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 interact, or are enabled to interact, with one another. In some embodiments, metadata  183  includes configurable properties, flags, and/or lists that indicate whether sub-events are delivered to varying levels in the view or programmatic hierarchy. 
     In some embodiments, a respective event recognizer  180  activates event handler  190  associated with an event when one or more particular sub-events of an event are recognized. In some embodiments, a respective event recognizer  180  delivers event information associated with the event to event handler  190 . Activating an event handler  190  is distinct from sending (and deferred sending) sub-events to a respective hit view. In some embodiments, event recognizer  180  throws a flag associated with the recognized event, and event handler  190  associated with the flag catches the flag and performs a predefined process. 
     In some embodiments, event delivery instructions  188  include sub-event delivery instructions that deliver event information about a sub-event without activating an event handler. Instead, the sub-event delivery instructions deliver event information to event handlers associated with the series of sub-events or to actively involved views. Event handlers associated with the series of sub-events or with actively involved views receive the event information and perform a predetermined process. 
     In some embodiments, data updater  176  creates and updates data used in application  136 - 1 . For example, data updater  176  updates the telephone number used in contacts module  137 , or stores a video file used in video player module  145 . In some embodiments, object updater  177  creates and updates objects used in application  136 - 1 . For example, object updater  177  creates a new user-interface object or updates the position of a user-interface object. GUI updater  178  updates the GUI. For example, GUI updater  178  prepares display information and sends it to graphics module  132  for display on a touch-sensitive display. 
     In some embodiments, event handler(s)  190  includes or has access to data updater  176 , object updater  177 , and GUI updater  178 . In some embodiments, data updater  176 , object updater  177 , and GUI updater  178  are included in a single module of a respective application  136 - 1  or application view  191 . In other embodiments, they are included in two or more software modules. 
     It shall be understood that the foregoing discussion regarding event handling of user touches on touch-sensitive displays also applies to other forms of user inputs to operate multifunction devices  100  with input-devices, not all of which are initiated on touch screens. For example, mouse movement and mouse button presses, optionally coordinated with single or multiple keyboard presses or holds; contact movements such as taps, drags, scrolls, etc., on touch-pads; pen stylus inputs; movement of the device; oral instructions; detected eye movements; biometric inputs; and/or any combination thereof are optionally utilized as inputs corresponding to sub-events which define an event to be recognized. 
       FIG. 2  illustrates a portable multifunction device  100  having a touch screen  112  in accordance with some embodiments. The touch screen optionally displays one or more graphics within user interface (UI)  200 . In this embodiment, as well as others described below, a user is enabled to select one or more of the graphics by making a gesture on the graphics, for example, with one or more fingers  202  (not drawn to scale in the figure) or one or more styluses  203  (not drawn to scale in the figure). In some embodiments, selection of one or more graphics occurs when the user breaks contact with the one or more graphics. In some embodiments, the gesture optionally includes one or more taps, one or more swipes (from left to right, right to left, upward and/or downward) and/or a rolling of a finger (from right to left, left to right, upward and/or downward) that has made contact with device  100 . In some implementations or circumstances, inadvertent contact with a graphic does not select the graphic. For example, a swipe gesture that sweeps over an application icon optionally does not select the corresponding application when the gesture corresponding to selection is a tap. 
     Device  100  optionally also includes one or more physical buttons, such as “home” or menu button  204 . As described previously, menu button  204  is, optionally, used to navigate to any application  136  in a set of applications that are, optionally executed on device  100 . Alternatively, in some embodiments, the menu button is implemented as a soft key in a GUI displayed on touch screen  112 . 
     In some embodiments, 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  is, optionally, used to turn the power on/off on the device by depressing the button and holding the button in the depressed state for a predefined time interval; to lock the device by depressing the button and releasing the button before the predefined time interval has elapsed; and/or to unlock the device or initiate an unlock process. In an alternative embodiment, device  100  also accepts verbal input for activation or deactivation of some functions through microphone  113 . Device  100  also, optionally, includes one or more contact intensity sensors  165  for detecting intensity of contacts on touch screen  112  and/or one or more tactile output generators  167  for generating tactile outputs for a user of device  100 . 
       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  optionally include circuitry (sometimes called a chipset) that interconnects and controls communications between system components. Device  300  includes input/output (I/O) interface  330  comprising display  340 , which is typically a touch screen display. I/O interface  330  also optionally includes a keyboard and/or mouse (or other pointing device)  350  and touchpad  355 , tactile output generator  357  for generating tactile outputs on device  300  (e.g., similar to tactile output generator(s)  167  described above with reference to  FIG. 1A ), sensors  359  (e.g., optical, acceleration, proximity, touch-sensitive, and/or contact intensity sensors similar to contact intensity sensor(s)  165  described above with reference to  FIG. 1A ). Memory  370  includes high-speed random access memory, such as DRAM, SRAM, DDR RAM or other random access solid state memory devices; and optionally includes non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. Memory  370  optionally includes one or more storage devices remotely located from CPU(s)  310 . In some embodiments, memory  370  stores programs, modules, and data structures analogous to the programs, modules, and data structures stored in memory  102  of portable multifunction device  100  ( FIG. 1A ), or a subset thereof. Furthermore, memory  370  optionally stores additional programs, modules, and data structures not present in memory  102  of portable multifunction device  100 . For example, memory  370  of device  300  optionally stores drawing module  380 , presentation module  382 , word processing module  384 , website creation module  386 , disk authoring module  388 , and/or spreadsheet module  390 , while memory  102  of portable multifunction device  100  ( FIG. 1A ) optionally does not store these modules. 
     Each of the above identified elements in  FIG. 3  are, optionally, stored in one or more of the previously mentioned memory devices. Each of the above identified modules corresponds to a set of instructions for performing a function described above. The above identified modules or programs (i.e., sets of instructions) need not be implemented as separate software programs, procedures or modules, and thus various subsets of these modules are, optionally, combined or otherwise re-arranged in various embodiments. In some embodiments, memory  370  optionally stores a subset of the modules and data structures identified above. Furthermore, memory  370  optionally stores additional modules and data structures not described above. 
     Attention is now directed towards embodiments of user interfaces (“UI”) that is, optionally, 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 are, optionally, implemented on device  300 . In some embodiments, user interface  400  includes the following elements, or a subset or superset thereof:
         Signal strength indicator(s)  402  for wireless communication(s), such as cellular and Wi-Fi signals;   Time  404 ;   Bluetooth indicator  405 ;   Battery status indicator  406 ;   Tray  408  with icons for frequently used applications, such as:   Icon  416  for telephone module  138 , labeled “Phone,” which optionally includes an indicator  414  of the number of missed calls or voicemail messages;   Icon  418  for e-mail client module  140 , labeled “Mail,” which optionally includes an indicator  410  of the number of unread e-mails;   Icon  420  for browser module  147 , labeled “Browser;” and   Icon  422  for video and music player module  152 , also referred to as iPod (trademark of Apple Inc.) module  152 , labeled “iPod;” and   Icons for other applications, such as:   Icon  424  for IM module  141 , labeled “Text;”   Icon  426  for calendar module  148 , labeled “Calendar;”   Icon  428  for image management module  144 , labeled “Photos;”   Icon  430  for camera module  143 , labeled “Camera;”   Icon  432  for online video module  155 , labeled “Online Video”   Icon  434  for stocks widget  149 - 2 , labeled “Stocks;”   Icon  436  for map module  154 , labeled “Map;”   Icon  438  for weather widget  149 - 1 , labeled “Weather;”   Icon  440  for alarm clock widget  149 - 4 , labeled “Clock;”   Icon  442  for workout support module  142 , labeled “Workout Support;”   Icon  444  for notes module  153 , labeled “Notes;” and   Icon  446  for a settings application or module, which provides access to settings for device  100  and its various applications  136 .       

     It should be noted that the icon labels illustrated in  FIG. 4A  are merely exemplary. For example, icon  422  for video and music player module  152  are labeled “Music” or “Music Player.” Other labels are, optionally, used for various application icons. In some embodiments, a label for a respective application icon includes a name of an application corresponding to the respective application icon. In some embodiments, a label for a particular application icon is distinct from a name of an application corresponding to the particular application icon. 
       FIG. 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 ). Device  300  also, optionally, includes one or more contact intensity sensors (e.g., one or more of sensors  357 ) for detecting intensity of contacts on touch-sensitive surface  451  and/or one or more tactile output generators  359  for generating tactile outputs for a user of device  300 . 
     Although some 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 are, optionally, used for other user interfaces described herein. 
     Additionally, while the following examples are given primarily with reference to finger inputs (e.g., finger contacts, finger tap gestures, finger swipe gestures), it should be understood that, in some embodiments, one or more of the finger inputs are replaced with input from another input device (e.g., a mouse based input or stylus input). For example, a swipe gesture is, optionally, replaced with a mouse click (e.g., instead of a contact) followed by movement of the cursor along the path of the swipe (e.g., instead of movement of the contact). As another example, a tap gesture is, optionally, replaced with a mouse click while the cursor is located over the location of the tap gesture (e.g., instead of detection of the contact followed by ceasing to detect the contact). Similarly, when multiple user inputs are simultaneously detected, it should be understood that multiple computer mice are, optionally, used simultaneously, or a mouse and finger contacts are, optionally, used simultaneously. 
     As used herein, the term “focus selector” refers to an input element that indicates a current part of a user interface with which a user is interacting. In some implementations that include a cursor or other location marker, the cursor acts as a “focus selector,” so that when an input (e.g., a press input) is detected on a touch-sensitive surface (e.g., touchpad  355  in  FIG. 3  or touch-sensitive surface  451  in  FIG. 4B ) while the cursor is over a particular user interface element (e.g., a button, window, slider or other user interface element), the particular user interface element is adjusted in accordance with the detected input. In some implementations that include a touch-screen display (e.g., touch-sensitive display system  112  in  FIG. 1A  or touch screen  112  in  FIG. 4A ) that enables direct interaction with user interface elements on the touch-screen display, a detected contact on the touch-screen acts as a “focus selector,” so that when an input (e.g., a press input by the contact) is detected on the touch-screen display at a location of a particular user interface element (e.g., a button, window, slider or other user interface element), the particular user interface element is adjusted in accordance with the detected input. In some implementations focus is moved from one region of a user interface to another region of the user interface without corresponding movement of a cursor or movement of a contact on a touch-screen display (e.g., by using a tab key or arrow keys to move focus from one button to another button); in these implementations, the focus selector moves in accordance with movement of focus between different regions of the user interface. Without regard to the specific form taken by the focus selector, the focus selector is generally the user interface element (or contact on a touch-screen display) that is controlled by the user so as to communicate the user&#39;s intended interaction with the user interface (e.g., by indicating, to the device, the element of the user interface with which the user is intending to interact). For example, the location of a focus selector (e.g., a cursor, a contact or a selection box) over a respective button while a press input is detected on the touch-sensitive surface (e.g., a touchpad or touch screen) will indicate that the user is intending to activate the respective button (as opposed to other user interface elements shown on a display of the device). 
     Management System of Browser Window Processes 
       FIG. 5  is a flowchart illustrating a method  500  for managing a plurality of windows of a browser application in accordance with some embodiments. The method allows for separately processing actions by the user with a window of the browser application by starting a separate process for each opened window of the browser application. In turn, the browser application manages and monitors the processes of its windows. This includes that the browser application initially assigns a priority level to each process and upon detection of a decreased activity level of the process, assigning the process to a lower priority level.  FIG. 5  is a flowchart illustrating a method for identifying background browser processes and inserting one or more of the background processes into a process termination queue for the operating system running the browser in accordance with some embodiments. 
     The method illustrated in  FIG. 5A  decreases memory usage and processing requirements by suspending inactive processes. Suspending inactive processes frees up processing capability of a device such that other processes can be performed. For battery-operated electronic devices, suspending inactive processes conserves power and increases the time between battery charges. Although the method is described with the operating system  126  of device  100  performing the depicted steps, in other embodiments, various other modules of a device such as device  100  perform the depicted steps. 
     The method  500  is performed at an electronic device  100  with a display  200  and an input device, such as the portable multifunction device  100  shown in  FIG. 1A  or device  300  shown in  FIG. 3 , as may be controlled by specially programmed code (computer programming instructions) contained in the graphics module  132 , wherein such specially programmed code is not natively present in the device  300 . In some embodiments, the display is a touch screen display and a touch-sensitive surface is on the display. In some embodiments, the display is separate from the touch-sensitive surface. Some operations in the methods are, optionally, combined and/or the order of some operations is, optionally, change. Some embodiments of the method  500  may include fewer, additional, or different steps than those shown in  FIG. 5 , and the steps may be performed in different orders. The steps of the method  500  are described with respect to example browser applications managing browser windows as illustrated in  FIGS. 6, 7A and 7B . 
     Referring to  FIGS. 5A, 5B, 6A, and 6B  the process manager  604  as part of the computer operating system  126  assigns  505  a priority level to processes running on the electronic device  100 , one of the processes comprising a browser application  601 . The priority levels of all processes are stored in a process priority list  605 . In some embodiments, the process manager  604  is a daemon process that runs in the background and manages all of the processes running on the electronic device  100 . In some embodiments, the process manager  604  is responsible for launching and terminating applications on the electronic device  100 . In some embodiments, the computer operating system includes the application manager  608  that is responsible for managing applications running on the electronic device  100 . For example, the application manager  608  can place an application process in the background or foreground. An example of an application manager is the “springboard” module, which is an application that manages the “home screen,” as illustrated in  FIG. 4A , of electronic devices. In some embodiments, the computer operating system  126  includes a single process/application managing module combining the process manager  604  and the application manager  608 . 
       FIGS. 6A and 6B  illustrate block diagrams of a computer operating system  126  and a browser application  601  that manages and monitors the processes  610  of its browser windows based on assigned priority levels  630 , according to some embodiments.  FIG. 6B  illustrates the browser application  601 , the process priority list  605 , and one or more application modules  625 . In some embodiments, the browser application  601  is the browser module  147  depicted in  FIG. 1 . The browser application  601  further includes one or more stand-alone window processes  610 , each window process  610  further including an activity level  615 . In some embodiments, the application modules  625  are the application modules described above with reference to  FIG. 1 . In some embodiments, as illustrated in  FIG. 6B , the process priority list  605  includes a plurality of priority levels or tiers  630 . 
     In some embodiments, the computer operating system  126  includes the kernel  606  among other modules. The kernel  606  manages system resources, such as the communication between hardware and software components. The kernel  606  allows other programs, such as the browser application  601  or media daemon  614 , to use these system resources. In some embodiments, the system resources include one or more Central Processing Units (CPUs) or processing cores to run or execute programs, computer memory, and the other computing components as illustrated in  FIG. 1A . For example, the kernel  606  manages the amount of memory that is allocated to a given process can use and determines what to do if not enough memory is available. In some embodiments, if not enough memory is available, the kernel  606  suspends one of the processes running on the electronic device  100 . In some embodiments, the kernel  606  provides a page scanning process that searches for unused pages of memory (e.g., RAM) that can be reclaimed for other processes. In some embodiments, the kernel  606  includes the process manager  604  and/or application manager  608 . In some embodiments, the kernel  606  includes the process priority list  605 . 
     The process priority list  605  includes a list of all processes that registered with the computer operating system  126  or memory management system according to the priority level assigned to each process. Each priority level includes zero, one or more processes. A priority level is initially associated with a process upon the process start to execute/run on the electronic device. In some embodiments, the priority level of a process changes during the execution/run time of the process. In some embodiments, the computer operating system  126  reassigns the priority level of a process based on the activity level of the process, e.g., whether the process runs in the foreground or in the background. In some embodiments, the process priority list  605  is used to order and prioritize the various processes being run on a device, such as the electronic device  100 . In some embodiments, the process priority list includes a plurality of propriety levels or tiers, which various processes are assigned to. In some embodiments, the process priority list  605  includes eleven total tiers, with tiers ten through four (T10-T4) assigned to foreground processes, tiers three through one (T3-T1) assigned to background processes, and tier zero (T0) assigned to processes that are tagged for being suspended in case of a computing resources shortage. In some embodiments, process priority list  605  includes three total tiers. 
     In some embodiments, as illustrated in  FIG. 6B , the process priority list  605  includes three different priority levels, a top tier level  630   a , a mid tier level  630   b , and a zero or low tier level  630   c . Each process is associated with one of the levels. In some embodiments, the processes within a priority level (tier) are ranked according to the time, when the process was associated with the priority level, from the latest time to the earliest time. In some embodiments, the priority of a process is determined by the computer operating system  126 , including the kernel  606 , the process manager  604 , and the application manager  608 , or an application, such as the browser application  601 , managing the process. Some examples of processes that range from low priority to high priority include but are not limited to suspended processes, background processes, foreground processes and system processes. Typically, suspended processes are the lowest priority processes and system processes are the highest priority processes. Generally, it is desirable to suspend low priority processes before suspending high priority processes. In some embodiments, the computer operating system  126  employs a policy to suspend processes of the lowest priority level if system resources are required that exceed the amount of available system resources. This allows for a more coarse grain approach of managing system resources based on priority level. In some embodiments, this policy includes suspending processes according to the time that the process had been associated with the lowest priority level. Thus, the lowest priority level process with the earliest association time is suspended first. This allows for a more fine grain approach of managing system resources by suspending processes within a priority level from earliest to latest association time. 
     In response to receiving  510  an action to open a window of the browser application, the browser application  601  starts  515  execution of a process for opening the window, and associates  520  the process with the window. As illustrated in  FIG. 6A , in some embodiments, the browser application  601  starts  515  one or more window process  610  at different times upon the user opening various web pages within the browser application. Each window process opens a different window, also referred to as browser window, which is displayed within a user interface of the browser application. For example, each window displays the content of a web page opened by the user within the browser application. In some embodiments, the action to open a window of the browser application includes an action to open a tab window within the browser application. In some embodiments, upon initially starting the browser application, the browser application  601  also start an initial window process. In some embodiments, the initial window process opens a default window within the browser application. In some embodiments, the default window is based on the recent browsing history associated with the browser application or specified by the user in a configuration setting of the browser application. In some embodiments, multiple web pages open within the browser application are all associated with a single process by the browser application. 
       FIG. 7  illustrates a user interface of the browser application that includes multiple browser windows, according to some embodiments. The user interface of the browser application includes a web browser  705  that is displayed on the display  200  of the electronic device  100  described above with reference to  FIGS. 1A, 2 and 4A . The web browser  705  further includes a URL bar  706 , a new tab option  707 , and one or more tab windows  710 . A user of a computing device such as device  100  uses the web browser  705  to access web pages on the internet. In some embodiments, to access a certain web page, the user enters a URL into the URL bar  706 . Responsive to the user entering a URL into the URL bar  706 , the web browser displays a web page  720  associated with the URL. The tab window  710  and its content, e.g., the content of a web page, are displayed on the display  200  in a foreground view of the user interface of the browser application that is visible to the user. The window displayed in the foreground view is also referred to as the active window of the browser application. Responsive to the user selecting the new tab option  707 , the web browser displays a new tab window  710  in the foreground view. In some embodiments, the new tab window includes a blank web page as the default window. 
     The other tab windows, including, e.g., the content of web pages, are placed in the background view of the user interface of the browser application. In some embodiments, the background view of the other tab windows is not visible on the display  200 . Windows in the background view are also referred to as inactive windows. In some embodiments, the foreground view of the active window and background views of the inactive windows displays the active window in front of the inactive windows. In these embodiments, the user has the option to select one of the displayed windows (active and inactive) to move to the foreground view, while moving the currently active window to the background view. 
     Upon selection of a window to move to the foreground view, the selected window is visibly displayed within the user interface of the browser application, while the inactive windows are visibly hidden from the display. In some embodiments, major portions of the inactive windows are visibly hidden (i.e. invisible) in the user interface of the browser application, while a minor portion of these inactive windows are still visible within the browser&#39;s user interface. In some embodiments, as illustrated in  FIG. 7 , the tab portion of tab window  710 A is visible, including a title of the tab window. In these embodiments, the user can move the invisible portions of inactive tab window  710 A to the foreground view by contacting the visible tab on the display  200 . In the example user interface illustrated in  FIG. 7 , the tab window  710 B and the corresponding web page  720  are in the foreground view, and the tab window  710 A and its corresponding web page are in the background view, which is visibly hidden (i.e., not visibly displayed on the display  200 ). In some embodiments, the web browser  705  includes more or fewer tab windows than are shown in  FIG. 7 . 
     In addition, in response to receiving  510  an action to open a window of the browser application, the browser application  601  assigns  525  a priority level from a plurality of priority levels to the process associated with the window, the priority level being related to the priority level of the browser application. As illustrated in  FIG. 6B , in some embodiments, the browser application  601  assigns different priority levels to each window process. For example, window process  610   b  is assigned to a priority level of the top tier level, while window process  610   a  is assigned to the mid tier level. In some embodiments, upon initially starting the execution of a window process  610 , the browser application assigns the window process the same priority level that the browser application has. In some embodiments, the browser application assigns the window process associated with an active window, i.e., a window in the foreground view, to the top tier level, and window process of any inactive window, i.e. a background window, to the zero tier level. In some embodiments, the browser applications assigns the window process to the mid tier level, when the associated window is changing from foreground to background view, and the window process is still performing bookkeeping tasks. 
     Bookkeeping tasks include, for example, finishing downloading the content of the web page displayed in the window that changed to an inactive status. Other examples of bookkeeping tasks include, but are not limited, to determining the use of system resources by the window process associated with the newly inactive window and releasing any allocated and unused resources. In some embodiments, upon completion of the bookkeeping task, the browser application assigns the window process, for which bookkeeping tasks were performed, from the mid tier level to the zero tier level or lowest priority level. 
     In some embodiments, the browser application also assigns a timestamp to a process when assigning a priority level to the process. The timestamp (TS) represents the time and date that the browser application assigns the priority level to the process. 
     In some embodiments, as illustrated in  FIG. 6B , processes are ordered within a priority level of the process priority list  605  according to their timestamps (TSs). The processes with an earlier timestamp are ranked lower than processes with a later timestamp within the same priority level. Thus, the process with the earliest timestamp (TS) and assigned to a priority level is ranked lowest within the priority level, while the process with the latest timestamp (TS) and assigned to the same priority level is ranked highest within the priority level. Thus, processes are ranked based on the length of time for which the process has been assigned to a priority level. For example, a process that has been assigned to the zero tier level for 10 minutes is ranked lower than a process that has been assigned to the zero tier level for one minute. 
     As illustrated in  FIG. 6B , other application modules  625  are also included within the process priority list  605 . For example, application modules include the calendar module, the email module, the camera module, the calculator widget, the video and music player module, and like modules, applications, and widgets as described above. The application modules  625  are some or all of the application modules described above with reference to  FIG. 1 . In some embodiments, the process manager, application manager or kernel typically assigns these application modules to the top tier level. Upon the window corresponding to the application module changing from foreground view to background view, the priority level of the application module is assigned to a lower priority level. In some embodiments, the application module associated with an inactive window is assigned to the zero tier level. In some embodiments, each of the application modules  625  is associated with one or more processes with each process assigned to a particular priority level. The application modules and other processes compete with the browser application  601  for the computing resources of the device. Although three application modules  625  are shown in  FIG. 6B , the electronic device can run more or fewer application modules in other embodiments. 
     The computer operating system  126  distributes  530  the computing resources among the processes based on the priority level of each process. Thus, in some embodiments, more computing resources are made available to process assigned to the top tier level. Furthermore, processes from higher priority level receive preference over lower priority level processes when distributing computing resources. This can lead to processes of lower priority level competing for resources, while higher priority level process have their needs for computing resources satisfied. 
     Following the execution of one or more window processes, the browser application  601  monitors  535  an activity level of each process associated with a window of the plurality of windows of the browser application. In some embodiments, as illustrated in  FIG. 6B , each window process  610  includes an activity level. In some embodiments, the activity levels include the window process being active or inactive, i.e. the window associated with the window process being a foreground view or background view, respectively. In these embodiments, the browser application is configured to display a window in the foreground view and a plurality of windows in a background view. A decrease in activity of the monitored process then includes moving the window associated with the monitored process from the foreground view to the background view of the browser application. 
     In some embodiments, monitoring an activity level of a process associated with a window includes monitoring user actions with content displayed within the window. The content displayed within the window of the browser application includes a web page, as described in detail with respect to  FIG. 7 . Actions or interactions by the user with the content includes, for example, browsing links associated with the web page or scrolling the content of the web page within the window of the browser application. Another example of actions includes the browser process displaying animations on a web page. 
     In some embodiments, the user action includes starting the execution of a daemon while interacting with the content of a web page within a browser window. For example, the user clicks on a web link within a web page that directs the browser application to video and/or audio content, upon which the browser application starts the video and music player module as a daemon to play the video and/or audio content. In some embodiments, as illustrated in  FIG. 6A , the browser application  601  links the daemon  614  with the process  610   d  associated with a window of the browser application. For example, the video and music player module is linked to the window process of the web page that included the link to the video and/or audio content. The monitored activity level of the linked process  610   d  depends the activity level of the daemon  614 . In case of a media daemon, e.g., the video and music player module, the activity level includes activity of the daemon downloading and/or playing the video and/or audio content. 
     In response to detecting  540  a decrease in the activity level of one of the monitored processes, the browser application  601  assigns  545  the monitored process with the decreased activity level to a lower priority level. In some embodiments, detecting a decrease in activity level of a monitored process includes receiving no user action with the monitored process for a continuous time period. In some embodiments, if the continuous time period of no user action exceeds an inactive time threshold, the browser application assigns the monitored process to a lower priority level. In some embodiments, a process without user action for an extended time period is assigned to the zero tier level. In some embodiments, the browser application assigns a window process to a priority level based on the amount of decrease in activity level of the monitored process. For example, if the window process is still performing bookkeeping task while being moved to the background view, the browser application assigns the window process to the mid tier level and not the zero tier level, since the window process is still active. Upon completion of the bookkeeping task, the browser application assigns the window process to the zero tier level, since the window process is now inactive. 
     Finally, in response to detecting  550  a total amount of all computing resources requested by the processes exceeding a maximum threshold of the electronic device, the computer operating system  126  selects  555  a process from the processes with the lowest priority level, and suspends  560  the selected process. The method  500  advantageously allows the computer operating system to individually prioritize the window processes of the browser application over other processes that are associated with other application modules based on resource notification or request. For example, the kernel, process manager or application manager receives a resource notification or request to reduce memory usage, because the available memory of the device  100  is not sufficient to run all processes based on the memory requested by each process. In some embodiments, a resource notification or request to reduce memory usage is received, because the device  100  is entering a “sleep” or energy saving mode. In other embodiments, a resource notification or request to reduce memory usage is received for various other reasons. Upon receipt of a resource notification or request, the computer operating system selects a process included in the process priority list to be suspended, if the requested resources exceed the maximum threshold of available computing resources. In some embodiments, as illustrated in  FIG. 6B , the operating system  126  through the kernel, the process manager, or the application manager, suspends the zero tier process with the earliest timestamp to preserve battery power, increase processing capability, or reduce memory usage. 
     In some embodiments, once a process to be suspended is selected, the process is suspended. In some embodiments, suspending the process comprises a full termination of the process, meaning the process is completely removed from the memory of the device. In some embodiments, suspending the process comprises pausing the process (or putting the process to “sleep”), but maintaining the process in the memory of the device. A full termination of the process maximizes the reduction of memory usage, while pausing the process allows the process to be resumed later. In some embodiments, a process continues running for a length of time to complete the execution of any pending tasks prior to being suspended. For example, a browser window process that is sending an email continues running for 10 seconds to complete, e.g., the task of uploading the email to a server before the process is suspended, to ensure that the email is properly sent. In some embodiments, suspending window process of the browser application includes closing the window associated with the window process. 
     The operations in the information processing methods described above are, optionally implemented by running one or more functional modules in information processing apparatus such as general purpose processors (e.g., as described above with respect to  FIGS. 1A and 3 ) or application specific chips. 
     The operations described above with reference to  FIGS. 5A, 5B, 6A and 6B  are, optionally, implemented by components depicted in  FIGS. 1A-1B . For example, the operations depicted in  FIG. 5A  and  FIG. 5B  are, optionally, implemented by the operating system  126  or other various modules depicted in  FIG. 1 . 
     The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best use the invention and various described embodiments with various modifications as are suited to the particular use contemplated. 
     Any of the steps, operations, or processes described herein may be performed or implemented with one or more hardware or software modules, alone or in combination with other devices. In some embodiments, a software module is implemented with a computer program product comprising a computer-readable medium containing computer program code, which can be executed by a computer processor for performing any or all of the steps, operations, or processes described. 
     Embodiments of the invention may also relate to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, and/or it may comprise a general-purpose computing device selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a tangible computer readable storage medium or any type of media suitable for storing electronic instructions, and coupled to a computer system bus. Furthermore, any computing systems referred to in the specification may include a single processor or may be architectures employing multiple processor designs for increased computing capability. 
     Embodiments of the invention may also relate to a computer data signal embodied in a carrier wave, where the computer data signal includes any embodiment of a computer program product or other data combination described herein. The computer data signal is a product that is presented in a tangible medium or carrier wave and modulated or otherwise encoded in the carrier wave, which is tangible, and transmitted according to any suitable transmission method. 
     Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

Metadata:
Filing Date: 20150601
Publication Date: 20180403
Grant Date: 20180403
Priority Date: 20140601
Inventors: BARRACLOUGH GAVIN
WEINIG SAMUEL M.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F16/957", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F9/4881", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F9/5011", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F17/30899", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F9/4818", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F9/4881", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 54701846