Cascading Menus
Smartphone supports cascading menus only to one additional level. They can be used
as long as they don't clutter the screen; in addition, the most common options must be
available at the top level and must not cascade. In the following figure, options for
filtering calls are provided in a cascading menu that appears at the bottom of the
menu.
A right-justified triangle next to a menu item indicates that it opens a cascading menu.
When the user presses the right arrow or the Action button, the second menu is
displayed. The user can then scroll up and down and press the Action button to select
the menu item.
Cascading Menus
Navigation Buttons
Smartphone provides two navigational buttons for users: the Home button and the
Back button.
The Home button is a powerful one-touch navigational tool that returns a user to the
Home screen from anywhere at any time.
The Back button is context dependent and is implemented to perform different
functions depending on the state of the application. It is generally designed to return
the user to the previous screen, with a few exceptions.
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