Abstract: A hierarchical system is used to store data items easily capable of thumbnail representation (such as images). Such a hierarchical system may allow a folder (or other grouping) to contain both data items and sub-folders. The display of such a folder uses two display areas. In one display area, sub-folders are displayed using a list view, where text is the primary method for the display of the sub-folders which are contained in the folder. In the other display area, a grid view is used to display the data items. Thumbnail images are the primary components of the grid view. Functionality available to a user will change based on whether the user is browsing the list view or the grid view.

Abstract: A UI (user interface) for gestural control enhances the navigation experience for the user by preventing multiple gestures from being inadvertently invoked at the same time. This problem is overcome by establishing two or more categories of gestures. For instance, the first category of gestures may include gestures that are likely to be invoked before gestures that are included in the second category of gestures. That is, gestures in the second category will typically be invoked after a gesture in the first category has already been invoked. One example of a gesture that falls into the first category may be a gesture that initiates operation of a device, whereas a gesture that falls into the second category may be change in volume. Gestures that fall into the second category require more criteria to be satisfied in order to be invoked than gestures that fall into the first category.