As portable electronic devices become more compact, and the number of functions performed by a given device increase, it has become a significant challenge to design a user interface that allows users to easily interact with a multifunction device. This challenge is particular significant for handheld portable devices, which have much smaller screens than desktop or laptop computers. This situation is unfortunate because the user interface is the gateway through which users receive not only content but also responses to user actions or behaviors, including user attempts to access a device's features, tools, and functions. Some portable communication devices (e.g., mobile telephones, sometimes called mobile phones, cell phones, cellular telephones, and the like) have resorted to adding more pushbuttons, increasing the density of push buttons, overloading the functions of pushbuttons, or using complex menu systems to allow a user to access, store and manipulate data. These conventional user interfaces often result in complicated key sequences and menu hierarchies that must be memorized by the user.
Many conventional user interfaces, such as those that include physical pushbuttons, are also inflexible. This may prevent a user interface from being configured and/or adapted by either an application running on the portable device or by users. When coupled with the time consuming requirement to memorize multiple key sequences and menu hierarchies, and the difficulty in activating a desired pushbutton, such inflexibility is frustrating to most users.
Because of the small size of display screens on portable electronic devices, only a portion of an electronic document is typically displayed on the screen at a given time. Thus, users need to translate (e.g., scroll) the displayed document to view the entire content of the document. Frequently, users may need to scroll to the top of the document after the user has scrolled down the document, for example to view a title or content at the top of the document. Limitations of conventional user interfaces require the user to manually scroll back to the top of a lengthy document. Manually scrolling to the top of the document on a small display screen may require additional key and gesture sequences that are time-consuming or awkward to perform.
Additionally, if the electronic document is a web page, users may need to scroll to the top of the web page or memorize key sequences to display the Uniform Resource Locator (URL) entry area.
Accordingly, there is a need for portable electronic devices with touch screen displays that have with more transparent and efficient user interfaces for displaying and navigating an electronic document (e.g., a web page). Such interfaces increase efficiency and user satisfaction with portable devices.