Although there is a need to perform explicit double buffering in Mobile Information Device Profile (MIDP) applications, the BlackBerry user interface (UI) implementation is double-buffered. This means there is no need to perform your own double buffering of UI images. Essentially, all drawing functions in net.rim.device.api.ui.Graphics objects are drawn to an off-screen bitmap by the system. When you call for a repaint of the screen, it draws this off-screen bitmap instead of sequentially painting the screen. This same drawing paradigm is true for all fields and field managers within the Blackberry UI.