Patent Publication Number: US-2015089454-A1

Title: Overscroll stretch animation

Description:
FIELD OF INVENTION 
     Embodiments of the present invention relate to the field of devices with electronic displays. More specifically, embodiments of the present invention relate to systems and methods for overscroll stretch animation. 
     BACKGROUND 
     Portable electronic systems, e.g., “smart” phones, tablets, and/or personal digital assistants, “wearable” electronic systems, including, e.g., “smart” watches and/or glasses, may generally only display a limited view of available information at any level of an information hierarchy. For example, such devices generally display a limited view of a document, a limited view of a list of documents, or a limited view of a list of other available features of a hand held computer system. For example, a portable electronic system may include hundreds to thousands of documents, media files or available programs, e.g., “apps.” However, the portable electronic system may only conveniently display icons representing a relatively small number, e.g., six to 12, of such icons on a single display image or “screen.” 
     It is common to scroll a display image, using gestures input via a touch screen, to scroll or move among various displayed subsets of such images. For example, a “sweeping” gesture may move from a first image of a first group of icons to a second image of a second group of icons. Such scrolling, also known as or referred to as “translating,” presents a user with a graphical user interface (GUI) metaphor of viewing a portion of a larger “app space” or “document space” through a smaller display-sized window. 
     It is a challenge for such graphical user interfaces to communicate various “events,” such as reaching an end or edge of such an “app space” or “document space,” in an intuitive manner. 
     SUMMARY OF THE INVENTION 
     Therefore, what is needed are systems and methods for overscroll stretch animation that provide intuitive feedback to a user. What is additionally needed are systems and methods for overscroll stretch animation that simulates stretching fabric as intuitive feedback to a user upon reaching a boundary of displayable information. A further need exists for systems and methods for overscroll stretch animation that are compatible and complementary with existing systems and methods of electronic display operation and programming. Embodiments of the present invention provide these advantages. 
     In accordance with a first method embodiment, a portion of displayable information is displayed on a touch screen display in a nominal state. A movement of an object on or near the touch screen display is detected. Responsive to the movement, a boundary limit of the displayable information is detected. Responsive to the detecting, the portion of displayable information is displayed in a distorted state. The distorted state simulates fabric stretching. 
     In accordance with another embodiment of the present invention, a computer system includes a touch screen display, at least one processor, a memory and one or more programs stored in the memory. The one or more programs are configured to be executed by the at least one processor to control the computer system to display a portion of displayable information in a nominal state on the touch screen display, detect a movement of an object on or near the touch screen display, responsive to the movement, detect a boundary limit of the displayable information, and responsive to a detection of the boundary limit, display the portion of displayable information in a distorted state on the touch screen display, wherein the distorted state changes a shape of items of the portion of displayable information. 
     In accordance with a further embodiment of the present invention, an article of manufacture including a computer readable medium having instructions stored thereon that, responsive to execution by an electronic system, cause the electronic system to perform operations including displaying a portion of displayable information in a nominal state, detecting a movement of an object on or near a touch screen display, responsive to the movement, detecting a boundary limit of the displayable information, and responsive to the detecting, displaying the portion of displayable information in a distorted state, wherein the distorted state simulates fabric stretching. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. Unless otherwise noted, the drawings are not drawn to scale. 
         FIG. 1A  illustrates an exemplary front view of a portable electronic system, which may be used as a platform to implement embodiments of the present invention. 
         FIG. 1B  is an exemplary block diagram of an exemplary portable electronic system, which may be used as a platform to implement embodiments of the present invention. 
         FIG. 2  illustrates an exemplary portion of user interface displayed on display of a portable electronic system, in accordance with embodiments of the present invention 
         FIG. 3  illustrates a distortion of displayed cells, in accordance with embodiments of the present invention. 
         FIG. 4  illustrates distortion of displayed cells, in accordance with embodiments of the present invention. 
         FIG. 5  illustrates a distortion of displayed cells, in accordance with embodiments of the present invention. 
         FIG. 6  illustrates a distortion of displayed cells, in accordance with embodiments of the present invention. 
         FIG. 7  illustrates a distortion of a displayed cell, in accordance with embodiments of the present invention. 
         FIG. 8  illustrates two images of a display of cells, in accordance with embodiments of the present invention. 
         FIG. 9  illustrates a method, in accordance with embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with these embodiments, it is understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the invention, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be recognized by one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the invention. 
     NOTATION AND NOMENCLATURE 
     Some portions of the detailed descriptions which follow (e.g., method  900 ) are presented in terms of procedures, steps, logic blocks, processing, and other symbolic representations of operations on data bits that may be performed on computer memory. These descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. A procedure, computer executed step, logic block, process, etc., is here, and generally, conceived to be a self-consistent sequence of steps or instructions leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. 
     It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the present invention, discussions utilizing terms such as “displaying” or “detecting” or “determining” or “setting” or “accessing” or “placing” or “testing” or “forming” or “mounting” or “removing” or “ceasing” or “stopping” or “coating” or “attaching” or “processing” or “performing” or “generating” or “adjusting” or “creating” or “executing” or “continuing” or “indexing” or “computing” or “translating” or “calculating” or “determining” or “measuring” or “gathering” or “running” or the like, refer to the action and processes of, or under the control of, a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. 
     As used herein, the term “picture element” or “pixel” is used to refer to or to describe the smallest portion of an electronic display that may be discriminated, e.g., directly addressed and/or controlled. For example, for a display described as having a resolution of 256 dots per inch (DPI), there are 256 pixels per inch. 
     As used herein, the term “cell” is used to refer to or to describe a group of picture elements. A cell may be any suitable size and/or shape. 
     As used herein, the term “icon” is used as understood by those of ordinary skill in the electronic arts. For example, an icon is generally understood to comprise an image on a computer generated display that represents a specific file, e.g., an electronic book, audio or video file, directory, window, option or program, e.g., “app.” Selection of an icon, e.g., “clicking” with a mouse or touching an icon on a touch screen display, generally launches software appropriate for that specific file type. For example, selection of a “music file” icon will initiate an audio player software and play the particular music selection. 
     Overscroll Stretch Animation 
       FIG. 1A  illustrates an exemplary front view of a portable electronic system  100 , which may be used as a platform to implement embodiments of the present invention. Portable electronic system  100  may comprise, for example, a “smart” phone, a tablet, and/or a personal digital assistant. Portable electronic system  100  may also comprise, for example, a “wearable” electronic system, including, e.g., a “smart” watch and/or glasses. Portable electronic system  100  is enclosed in a case or shell  101  of any suitable material. In some embodiments, various portions of portable electronic system  100  may be contained in multiple enclosures. For example, CPU  105  may be housed separately from display  125 . Portable electronic system  100  comprises a display unit  125  and may comprise a touch sensitive digitizer panel  130 , also known as or referred to as a “touch screen.” Touch sensitive digitizer panel  130  operates to indentify a point of contact  102  of a finger, stylus or other object. Item  102  may correspond to a cursor image on display  125 , in some embodiments. 
       FIG. 1B  is an exemplary block diagram of an exemplary portable electronic system  100 , which may be used as a platform to implement embodiments of the present invention. Electronic system  100  may be battery-powered, in some embodiments. Electronic system  100  includes an address/data bus  150  for communicating information, a central processor  105  functionally coupled with the bus for processing information and instructions. Central processor  105  may comprise multiple processors, e.g., a multi-core processor, or multiple separate processors, in some embodiments. Electronic system  100  also includes a volatile memory  115  (e.g., random access memory RAM) coupled with the bus  150  for storing information and instructions for the central processor  105 , and a non-volatile memory  110  (e.g., read only memory ROM) coupled with the bus  150  for storing static information and instructions for the processor  105 . Electronic system  100  also optionally includes a changeable, non-volatile memory  120  (e.g., flash) for storing information and instructions for the central processor  105  which can be updated after the manufacture of system  100 . In some embodiments, only one of ROM  110  or Flash  120  may be present. 
     Also included in electronic system  100  of  FIG. 1  is an optional input device  130 . Device  130  can communicate information and command selections to the central processor  100 . Input device  130  may be any suitable device for communicating information and/or commands to the electronic system  100 . For example, input device  130  may take the form of buttons, a joystick, a track ball, an audio transducer, e.g., a microphone, a touch sensitive digitizer panel, eyeball scanner and/or the like. A touch sensitive digitizer panel may comprise any suitable technology, e.g., capacitive, resistive, optical, acoustic and/or pressure responsive touch panels. Activation of a “touch” sensitive digitizer panel may not require actual touching of the panel  130  or the portable electronic system  100 , in some embodiments. For example, capacitive touch panels may sense proximity of a user&#39;s finger or an eyeball scanner may detect a direction of a user&#39;s gaze. 
     The display unit  125  utilized with the electronic system  100  may comprise a liquid crystal display (LCD) device, cathode ray tube (CRT), field emission device (FED, also called flat panel CRT), light emitting diode (LED), plasma display device, electro-luminescent display, electronic paper, electronic ink (e-ink) or other display device suitable for creating graphic images and/or alphanumeric characters recognizable to the user. Display unit  125  may have an associated lighting device, in some embodiments. Display unit  125  may comprise a weapon-mounted and/or head-mounted display, in some embodiments. 
     The touch sensitive digitizer panel  130  is generally associated with the display unit  125 . For example, a function of the touch sensitive digitizer panel  130  generally associated with the display unit  125  is to localize a touch input, e.g., from a finger or stylus, to a portion of display unit  125 , for example, a single icon image displayed on display unit  125 . The touch sensitive digitizer panel may be in front of the actual display device, e.g., in a viewer&#39;s optical path, or the touch sensitive digitizer panel may be outside of a viewer&#39;s optical path, e.g., behind or to the side of the display device. The touch sensitive digitizer panel  130  may have different planar dimensions in comparison to planar dimensions of a display unit  125 . For example, the touch sensitive digitizer panel  130  may be smaller than display unit  125 , e.g., the display unit  125  may extend beyond the touch sensitive digitizer panel  130 . Similarly, the touch sensitive digitizer panel  130  may be larger than display unit  125 , e.g., the touch panel may extend beyond the display unit. The touch sensitive digitizer panel may be integral to a display assembly, or a separate assembly within the electronic system  100 . 
     Electronic system  100  also optionally includes an expansion interface  135  coupled with the bus  150 . Expansion interface  135  can implement many well known standard expansion interfaces, including without limitation the Secure Digital Card interface, universal serial bus (USB) interface, Compact Flash, Personal Computer (PC) Card interface, CardBus, Peripheral Component Interconnect (PCI) interface, Peripheral Component Interconnect Express (PCI Express), mini-PCI interface, IEEE 1394, Small Computer System Interface (SCSI), Personal Computer Memory Card International Association (PCMCIA) interface, Industry Standard Architecture (ISA) interface, RS-232 interface, and/or the like. In some embodiments of the present invention, expansion interface  135  may consist of signals substantially compliant with the signals of bus  150 . 
     A wide variety of well known devices may be attached to electronic system  100  via the bus  150  and/or expansion interface  135 . Examples of such devices include without limitation rotating magnetic memory devices, flash memory devices, digital cameras, wireless communication modules, digital audio players and Global Positioning System (GPS) devices. 
     System  100  also optionally includes a communication port  140 . Communication port  140  may be implemented as part of expansion interface  135 . When implemented as a separate interface, communication port  140  may typically be used to exchange information with other devices via communication-oriented data transfer protocols. Examples of communication ports include without limitation RS-232 ports, universal asynchronous receiver transmitters (UARTs), USB ports, infrared light transceivers, ethernet ports, IEEE 1394 and synchronous ports. 
     System  100  optionally includes a radio frequency module  160 , which may implement a mobile telephone, a wireless network, e.g., IEEE 802.11 (“Wi-Fi”), Bluetooth, a pager, or a digital data link. Radio frequency module  160  may be interfaced directly to bus  150 , via communication port  140 , via expansion interface  135 , or any suitable interface. Various features of portable electronic system  100  may be implemented by a combination of hardware and/or software. Portable electronic system  100  may comprise additional software and/or hardware features (not shown) in some embodiments. 
       FIG. 2  illustrates an exemplary portion of user interface  200  displayed on display  125  of portable electronic system  100  ( FIG. 1B ), in accordance with embodiments of the present invention. Cells  220 ,  230 ,  240 ,  250 ,  260  and  270  illustrate a nominal state of displayed information of user interface  200 . Cells  220 - 270  may represent any displayable information of electronic system  100 . For example, cells  220 - 270  may represent icons corresponding to documents, e.g., e-reader book files, media files, e.g., pictures, audio files, video files, directories, application programs (“apps”) and/or other files available on portable electronic system  100 . Alternatively, cells  220 - 270  may represent portions of a single document or media file. For example, cells  22 - 270  may represent letters and/or words, or arbitrary groupings of letters and/or words in a document, e.g., a page or partial page of a book. Cells  220 - 270  may also represent, for example, portions of a single document or image, e.g., a web page. Cells  220 - 270  may be discrete, e.g., separated from one another, or they may be contiguous. 
     Line  210  represents the left most limit, or space boundary, of available displayable information. For example, the displayed portion of user interface  200  may represent a window into a greater whole or “space” of information, such as icons, and/or files available on portable electronic system  100 . A user may navigate, e.g., scroll, throughout the greater information space by virtual movement of the window, e.g., displayed image, within the greater space. Line  210  represents to the left most limit of such a greater space. Line  210  is not typically displayed. Similarly, there are upper, lower and right limits (not shown) or boundaries that are a part of the graphical user interface metaphor, which are generally not displayed. Accordingly, cells  220 - 270  are the “left most” cells that may be displayed. 
     In accordance with embodiments of the present invention, displayed cells, e.g., cells  220 - 270 , may be distorted to indicate that a space boundary such as line  210  has been reached in response to a user attempting to scroll beyond the limits of boundary  210 , e.g., “overscroll.” Alternatively, in accordance with embodiments of the present invention, displayed cells, e.g., cells  220 - 270 , may be distorted responsive to an “overscroll,” for example, receipt of a command, e.g., a gesture, to scroll beyond a space boundary. A “scroll” gesture may comprise a finger or stylus moving in a substantially linear manner across a touch sensitive panel, e.g., touch panel  130  ( FIG. 1B ). 
     Embodiments in accordance with the present invention are well suited to any abstraction of icon and display movement. For example, in a first abstraction, a displayed image represents a moveable window that shows a portion of a fixed field of icons. In such a first abstraction, movement gestures are understood to move the window. A second abstraction may have a fixed window in which a field of icons moves through. In such a second abstraction, movement gestures are understood to move the icons. Some computer systems may allow a user to select among such abstractions. For example, the “scroll lock” key on many personal computers allows a user, in some application programs, to select among such abstractions. Embodiments in accordance with the present invention are well suited to any abstraction of icon and display movement. 
       FIG. 3  illustrates a distortion  300  of displayed cells, in accordance with embodiments of the present invention. As the displayed cells are at the left most limit or boundary of the underlying display space, no further scrolling to the left is permitted. In response to a left “scroll” gesture  302 , e.g., an overscroll, the cells  320 ,  330 ,  350  and  360  are distorted, in accordance with embodiments of the present invention. Such distortion of the cells provides feedback to a viewer of the portable electronic system that a limit or boundary of the underlying display space has been reached. 
     In accordance with embodiments of the present invention, distortion  300  is based on a metaphor of simplified stretching of fabric. The illustrated distortion of cells corresponds to a stretching of fabric toward the point of contact  302 . For example, cells  320  and  350  are closest to the point of contact  302 , and are distorted more than cells  330  and  360 , which are farther away from the point of contact  302 . Cells  340  and  370  are the farthest away from the point of contact  302 , and may show little or no distortion, in some embodiments. 
     It is to be appreciated that the distortion of all illustrated cells is not identical. For example, as the point of contact  302  is below cell  320 , the bottom of cell  320  is distorted or stretched more than the top of cell  320 . In contrast, as the point of contact  302  is above cell  350 , to top of cell  350  is distorted or stretched more than the bottom of cell  350 . In other embodiments, all displayed cells may have the same amount of distortion. 
       FIG. 4  illustrates distortion  400  of displayed cells, in accordance with embodiments of the present invention.  FIG. 4  may be considered to display one or more cells. The content of the cell(s) illustrated is substantially textual. The cell(s), e.g., the textual content is distorted in the direction of the point of contact  402 , responsive to an overscroll in the left direction. 
     The distortions presented in  FIGS. 3 and 4  are in one dimension, e.g., the dimension of the scroll gesture, e.g., left as illustrated. The distortions presented in  FIGS. 3 and 4  are also substantially linear in the given direction. For example, each display line of a particular cell is shifted in the direction by the same number of pixels. It is appreciated that the shift may be a partial pixel per display line, resulting is slight “jumps,” e.g., when the accumulated shift of fractional pixels is greater than one pixel. 
     In addition, cells may be shifted at a different scale, in accordance with embodiments of the present invention. For example, cells comprising interior shapes, graphics and/or symbols may implement a “stair-step” shift to avoid or limit distorting such interior shapes, while approximating an overall distortion of a cell, as illustrated in  FIGS. 3 and 4 . 
     In addition, cells comprising textual information may be shifted based on a line of text, e.g., generally comprising multiple display lines, rather than on a display line basis. For example, the illustrated shift of  FIG. 4  is on a text-line basis, e.g., each line of text is shifted relative to the line above. Such text-line based shifting may maintain readability. As illustrated, the textual information of  FIG. 4  is set with a “ragged right” edge. Embodiments in accordance with the present invention are well suited to other styles of typesetting, including, for example, full justification, no justification, and right and/or left alignment. 
     In accordance with embodiments of the present invention, distortions corresponding in other directions may be presented responsive to overscroll commands to move beyond limits in any direction, including the cardinal directions, e.g., up, down, left, right, and in other directions, e.g., intermediate or diagonal directions. 
     In addition to substantially linear one-dimensional distortions previously presented, other forms of distortions are envisioned in keeping with the metaphor of stretching fabric, in accordance with embodiments of the present invention. 
       FIG. 5  illustrates a distortion  500  of displayed cells, in accordance with embodiments of the present invention. As the displayed cells are at the left most limit or boundary of the underlying display space, no further scrolling to the left is permitted. In response to a left “scroll” gesture  502 , e.g., an overscroll, the cells  520 ,  530 ,  550  and  560  are distorted, in accordance with embodiments of the present invention. Such distortion of the cells provides feedback to a viewer of the portable electronic system that a limit or boundary of the underlying display space has been reached. 
     The distortion  500  is non-linear in the direction of the scroll gesture  502 . For example, the distortion of cell  520  increases non-linearly from the top to the bottom of the cell. Such a distortion pattern may be a more complex and more accurate model of fabric stretching. 
     The illustrated distortion of cells  500  corresponds to a stretching of fabric in the direction of the overscroll gesture, e.g., to the left in  FIG. 5 . For example, cells  520  and  550  are closest to the boundary limit  210 , and are distorted more than cells  530  and  560 , which are farther away from the boundary limit  210 . Cells  540  and  570  are the farthest away from the boundary limit  210 , and may show little or no distortion, in some embodiments. For example, the limit line  210  guides the distortion, even if an actual point of contact does not reach the limit line  210 . 
     It is to be appreciated that the distortion of all cells is not identical. For example, as the line of gesture  502  is below cell  520 , the bottom of cell  520  is distorted or stretched more than the top of cell  520 . In contrast, as the line of gesture  502  is above cell  550 , to top of cell  550  is distorted or stretched more than the bottom of cell  550 . For example, the line of gesture  502  guides the distortion, even if an actual point of contact does not reach the limit  210 . 
     It is appreciated that the points of stretching for distortions  300  ( FIG. 3) and 500  are different. In distortion  300 , the stretching distortion is “aimed” at the point of contact  302  ( FIG. 3 ). In contrast, in distortion  500 , the stretching distortion is aimed at the intersection of limit  210  and a line of the overscroll gesture  502 . Embodiments in accordance with the present invention are well suited to either method of guiding a fabric stretching distortion. 
       FIG. 6  illustrates a distortion  600  of displayed cells, in accordance with embodiments of the present invention. As the displayed cells are at the left most limit or boundary of the underlying display space, no further scrolling to the left is permitted. In response to a left “scroll” gesture  602 , e.g., an overscroll, the cells  620  and  630  are distorted, in accordance with embodiments of the present invention. As the point of contact  602  is within the vertical extent of the cells  620  and  630 , e.g., between the top and the bottom of cells  620 ,  630 , the fabric-stretching distortion follows a complex, non-continuous curve focused or “aimed” at the point of contact  602 . As illustrated, the line of the gesture  602  is about in the middle of the cells  620 ,  630 , and the distortion of the cells is substantially symmetrical about the mid line of the cells, although that is not required. It is to be appreciated that the inflection of the complex distortion of the cells aligns with the line of the gesture  602 , in some embodiments. 
     The illustrated distortion of cells  600  corresponds to a stretching of fabric in the direction of the overscroll gesture, e.g., to the left in  FIG. 6 . For example, cell  620  is closest to the boundary limit  210 , and is distorted more than cell  530 , which is farther away from the boundary limit  210 . For example, the limit line  210  guides the distortion, even if an actual point of contact does not reach the limit line  210 . 
     Embodiments in accordance with the present invention are also well suited to complex linear fabric-stretching distortions as illustrated in cells  620 ′ and  630 ′ 
       FIG. 7  illustrates a distortion  700  of a displayed cell, in accordance with embodiments of the present invention. As the displayed cell is at the left most limit or boundary of the underlying display space, no further scrolling to the left is permitted. In response to a left “scroll” gesture  702 , e.g., an overscroll, the cell  720  is distorted, in accordance with embodiments of the present invention. 
     Cell  720  comprises a cell boundary or outline  722 , indicated by a heavy dark line. Call  720  also comprises a plurality of prominences or ridge lines  724 , indicated by solid lines, and a plurality of troughs or valleys  726 , indicated by dashed lines. The plurality of prominences  724  and plurality of troughs  726  may be illustrated by any suitable graphical means, including, for example, use of color, shading and/or shadowing. The plurality of prominences  724  in combination with the plurality of troughs  726 , e.g., the combination of highs and lows, indicate bunching of stretched fabric, in accordance with embodiments of the present invention. The distortion may converge to approximately a single point, however that is not required. 
       FIG. 8  illustrates two images of a display of cells, in accordance with embodiments of the present invention. The two images may be considered “screen shots.” In  FIG. 8  the cells generally correspond to discrete icons, e.g., images representing application software or “apps,” magazine articles, books, audio and/or video files. It is to be appreciated that cells are not required to correspond to icons, and may be contiguous, in accordance with embodiments of the present invention. 
     Image  800  illustrates a plurality of cells, including cells  810  and  820 . The cells are in a nominal or normal condition, e.g., undistorted. It is appreciated that cell  810  is larger than most of the other cells. It is also appreciated that cell  820  is primarily textual. Cell  830  is in the top row of displayed cells. Image  850  illustrates a plurality of cells in a distorted state. In response to a left “scroll” gesture  802 , e.g., an overscroll, the cells are distorted, e.g., the portions of the cells closest to the point of contact  802  are distorted in the direction of the scroll gesture, e.g., to the left. Cells  810 ′ and  820 ′, being below the line of the gesture  802 , are distorted such that they appear to “lean” to the left. Cells above the line of gesture  802 , e.g., cell  830 ′, are distorted such that they appear to “lean” to the right. In some embodiments, the bottom of cell  830 ′ has shifted, rather than the top of cell  830 ′. It is appreciated that the illustrated distortion of image  850  simulates or models fabric being stretched in the direction of the scroll gesture, in accordance with embodiments of the present invention. 
       FIG. 9  illustrates a method  900 , in accordance with embodiments of the present invention. In  910 , an electronic system, e.g., portable electronic system  100  of  FIG. 1A , displays a portion of displayable information in a nominal state. 
     In  920 , a movement of an object on or near the touch screen display is detected. The movement may represent a scroll gesture received by a touch screen. The object may be, for example, a user&#39;s finger or a stylus. In  930 , a boundary limit of the displayable information is detected. In  940 , responsive to the detection of the boundary limit, the portion of displayable information is displayed in a distorted state. The distortion may model or simulate fabric stretching. 
     In optional  950 , responsive to cessation of the movement, the portion of displayable information is displayed in a nominal state. For example, the distortion effect is removed or stopped. In this novel manner, a user is provided intuitive feedback as to a boundary of displayable information. Accordingly, the graphical user interface is improved, and the electronic system is beneficially more usable. 
     In accordance with some embodiments of the present invention, a scroll or translate command is not required to be received by a touch panel, e.g., touch sensitive panel  130  of  FIG. 1B . Other suitable forms of input, for example, discrete buttons, joysticks, track balls, eyeball trackers, biofeedback mechanisms and/or voice commands, for entering commands to a portable electronic system are well suited to embodiments in accordance with the present invention, and are considered within the scope of the present invention. 
     Embodiments in accordance with the present invention provide systems and methods for overscroll stretch animation that provide intuitive feedback to a user. In addition, embodiments in accordance with the present invention provide systems and methods for overscroll stretch animation that simulates stretching fabric as intuitive feedback to a user upon reaching a boundary displayable information. Further, embodiments in accordance with the present invention provide systems and methods for overscroll stretch animation that are compatible and complementary with existing systems and methods of electronic display operation and programming. 
     Various embodiments of the invention are thus described. While the present invention has been described in particular embodiments, it should be appreciated that the invention should not be construed as limited by such embodiments, but rather construed according to the below claims.