Command mapping and handling
In the Nokia Asha software platform, Commands (except Back command) can be mapped to option menu and to toolbar.
Toolbar and Option menu
In Screen and Canvas, the highest priority commands are shown on the screen as a toolbar buttons. All the other Commands (except Back and Exit commands) are listed in the option menu.
| Series 40 full touch | Nokia Asha software platform |
|---|---|
| In the Series 40 full touch, Command/IconCommand with the highest priority will be assigned to action button 1, and other commands will be assigned to action button 2 (under the option menu). | In the Nokia Asha software platform, it is the Command’s priority that decides the placement in the toolbar button and then the command’s type (1. STOP, 2. CANCEL, 3. EXIT) . |
Back key
There is a new physical button, back key in the device. MIDlets can utilize the back key for their “UI flow” purposes, i.e. traversal between different views within the application. When the main-level has been reached, the back button press is treated as exit. The back key is also used to return to previous UI state.
Back key behaviour
If MIDlet has Exit Command implemented, pressing back key closes the MIDlet.
If MIDlet has Back Command implemented, pressing back key handles the Back Command.
If MIDlet has Back and Exit Commands implemented, Back command is mapped to the back key and Exit Command to the option menu.
If Exit Command is mapped to the back key, it is normally handled by using
commandAction()method (it is possible, for example, to show confirmation dialog before exiting).MIDlet is closed by pressing back key, even if the Exit Command is not implemented.
MIDlets can be closed also by swiping horizontally across the screen.
If there is a custom implementation of the back command, the only way to close the MIDlet is to swipe the screen.
The back key can terminate the MIDlet only if a back or an exit command have not been added to the current displayable.
Note: Developers porting their full-canvas MIDlet should remove any back or exit buttons from their MIDlet canvas and use Back/Exit command in order to map back-stepping to the hardware back button.