Texas Instruments TI89 Developer Guide - Page 120

78 9.2. Chapter 9: Application Control Flow default: EV_defaultHandler(event); break; } } The application's main entry point has two parameters - a pointer to the application's frame and a pointer to an event notification structure. The application typically utilizes a switch statement to decode what kind of event it received. The appropriate case label then acts on the event accordingly. Events which are not picked out by any case label are given default handling by the routine EV_defaultHandler. The application may choose to modify the default behavior of some events by acting on them then passing them on to EV_defaultHandler. The application relinquishes control to the operating system after handling an event by returning from its main entry point. Event Structure Layout typedef struct SEvent { UINT command; UINT sourceID; UINT side; UINT status; union { EventInfo eventInfo; KeyInfo keyInfo; PasteInfo pasteInfo; PasteHandleInfo pasteHandleInfo; PaintInfo paintInfo; StartInfo startInfo; MenuInfo menuInfo; ModeInfo modeInfo; } info; } Event, *PEvent; command - A command number encoding which event occurred. This may be, among others, a keyboard event, a message from the window system, or an application-to-application message. See the next section (9.3. Commands) for details about each command type. sourceID - The ID of the application which originated the event-usually the application which is currently running. TI-89 / TI-92 Plus Developer Guide Not for Distribution Beta Version January 26, 2001