Listing 1a  
Code for GUI_Init.


/*‹‹‹‹‹‹‹‹‹‹‹‹-  Public Function  ‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹*/
// Name: GUI_Init
// Brief: Initialization function associated with the GUI task.
// Called By: This function is called as part of OS initialization. This function 
// creates the UI_DISPLAY, UI_EVENT_MANAGER, and UI_WINDOW_MANAGER required by Zinc. Once // these are created, the GUI interface is ready to roll.
// Comments:
// The objects created by this function are never deleted! This is not ordinarily done, // but in this case the objects are fundamental to the execution of the GUI interface, // they are intended to live forever, so there is still peace in heap-ville.
/*‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹*/
int GUI_Init(int TaskIndex)
{
  // Create the display interface object. The display constructor performs all the video        
  // controller configuration, and prepares font bitmap information for use by text 
  // routines (an illustration of the beauty of encapsulation).
UI_DISPLAY *display = new UI_LCD_DISPLAY();
  // create the eventManager (the first parameter is required, the second indicates how    
  // many events the event manager queue should expect to manage):
eventManager = new UI_EVENT_MANAGER(display, 40);
  // create the window manager:
windowManager = new UI_WINDOW_MANAGER(display, eventManager);
	return(TRUE);
}



Listing 1b
Code for GUI_Task.

/*‹‹‹‹‹‹‹‹‹‹‹‹-  Public Function  ‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹*/
// Name: GUI_Task
// Brief: This task interfaces the Zinc GUI library with the real-time operating system // and other system tasks.
// Called By: This function is called as part of OS initialization.
// Comments:
// This function runs forever. It first creates the main window, then continuously loops // processing Zinc events and suspending waiting for OS-generated messages. 
/*‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹*/
void GUI_Task (void)
{
	// a few automatic variables:
	UI_EVENT ZincEvent;		// used to pass OS-messages to library
	EVENT_TYPE ccode;		// Zinc defined status code
	MESSAGE *pMessage = NULL;     // OS defined message type
	// pop the first window up on the display:
	windowManager->Add(new MAIN_SCREEN());

	for(;;)			// never returns
	{
		if (pMessage)
		{
	ZincEvent.type = MSG_TYPE_OS;		// user define message type
	ZincEvent.data = (void *) pMessage; 	// pass message pointer to app 		eventManager->Put(ZincEvent);		// place Zinc event in queue
		}
	// process any pending Zinc events:
	int iQueStatus = eventManager->Get(ZincEvent, Q_NO_BLOCK);

	while(iQueStatus != QUEUE_EMPTY) // there may be several events!! 
	{
	// allow the window manager to route the message to the correct window object:
	windowManager->Event(ZincEvent);
	// get the next event (if any)
		iQueStatus = eventManager->Get(ZincEvent, Q_NO_BLOCK);
	}
	// Go to sleep until another message arrives from some other task or
	// timer in the system:
	pMessage = WaitForMessage(GUI_QUEUE, INFINITE);
	}
}