Troubleshooting guide

1
Creating UIs
Elements of a BlackBerry device UI
Screens
The main structure for a BlackBerry® device UI is the Screen object. A BlackBerry device application may display
more than one screen at a time, but only one screen in an application is active at one time.
The UI APIs initialize simple Screen objects. Once you create a screen, you can add fields and a menu to the
screen and display it to the BlackBerry device user by pushing it onto the UI stack. The
menu object has associated
menu items that are runnable objects, which perform a specific task when the BlackBerry device user selects one
of the items. For example, menu items may invoke the necessary code to establish a network connection, commit a
data object to memory, or close the application. For more sophisticated custom applications, you can customize
the BlackBerry device UI and implement new field types, as required. You can also add custom navigation and
trackwheel behavior.
The Screen class does not implement disambiguation, which is required for complex input methods, such as
international keyboards and the BlackBerry 7100 Series. For seamless integration of the different input methods,
extend
Field or one of its subclasses. Do not use Screen objects for typing text.
Elements of a BlackBerry device UI
Create a screen
Adding UI components to a screen
Creating custom UI components
Adding menu items to BlackBerry applications
Arrange UI components
Set field focus and navigation
Listen for field focus changes
Respond to UI events
Listen for field property changes
Manage foreground events
Manage drawing areas