GUIBaseContext :: doTimer - Handler for timer event

The handler is called when timer event (GEV_Timer) is fired for the control. Timer events are fired for a control, when a timer has been activated by calling startTimer(). You may overload the handler in order perform timer actions for the control.

The handler should return one of the following return codes:

• -1 (not handled) - the event handler will be removed from the handler list and is not called anymore.
• 1 (error) - Returning an error has no effect for the event.
• 0 (ok) - Event handler terminated successfully.