Displaying content on a call screen
On BlackBerry® devices that are running BlackBerry® Device Software 5.0 or later, you can customize the incoming call screen and active call screen to display content by using the Phone Screen API that is provided in the net.rim.blackberry.api.phone.phonegui package. For example, you can display information that is provided by your application when a BlackBerry device user receives a call from a specific caller.
The device displays the content on the lower part of the call screen. If multiple applications provide content for a call screen, the device displays each application's content in sequence for approximately two seconds until the next call screen appears. For example, if you display content on the incoming call screen, the device displays the content until the user answers the call and the active call screen appears.
The Phone Screen sample application that is included in the BlackBerry® Java® SDK demonstrates how to use this API.