Do Carbon Idle Event Timers work?

Hello everyone,

I'd first like to say that I have long used this forum as a valuable resource, and I just now got around to registering, so this is my first post! YaY!

Anyway, I am trying to set up a Carbon event loop that uses an idle event timer to drive the game loop. My problem is this: Xcode will not compile the callback function that my timer calls.

This is the error I get:
Prototypes.h:36: error: parse error before "EventIdleAction"

That error refers to the third line in this prototype:

pascal void NextFrame(  EventLoopTimerRef	timer,
			void		        *userData,
			EventIdleAction	        action );

I have no problem compiling a regular event timer callback, so it seems that EventIdleAction is the only thing giving me grief. I have read the Apple online docs, but the very code they supply does not compile. I have searched and searched for an example that uses idle event loop timers, and I have found nothing.

I set my timer up like this (almost exactly like the example in the Apple docs):

	EventLoopRef			mainLoop;		
	EventLoopIdleTimerUPP           idleTimerUPP;   
	EventLoopTimerRef		theTimer;		

	mainLoop = GetMainEventLoop();				
	idleTimerUPP = NewEventLoopTimerUPP( NextFrame );   
	InstallEventLoopIdleTimer( mainLoop,	
		                   0,	
                                   kEventDurationNoWait,		
		                   idleTimerUPP,			
		                   NULL,
		                   &theTimer );

        RunApplicationEventLoop();

Has anyone had this problem? If not, can someone please post a working example (or a summary of one anyway)?

Thanks a lot!


---
Dard.

[ThemsAllTook]

Looking in CarbonEventsCore.h, I'm not seeing a typedef for EventIdleAction. What I did find was this:

typedef CALLBACK_API( void , EventLoopIdleTimerProcPtr )(EventLoopTimerRef inTimer, EventLoopIdleTimerMessage inState, void *inUserData);

Those are probably the function parameters you actually want. I have no idea why the Apple docs would have gotten it wrong, though...

Alex Diener

According the the CarbonEventsCore.h file:

*    Idle timers are
 *    only called when there is no user activity occuring in the
 *    application. This means that the user is not actively
 *    clicking/typing, and is also not in the middle of tracking a
 *    control, menu, or window

I think what you want is:

EventLoopTimerUPP myFrameUPP = NewEventLoopTimerUPP (NextFrame),
EventLoopTimerRef nextFrameTimer;


	InstallEventLoopTimer(
			GetCurrentEventLoop(),
			kEventDurationNoWait,
			kEventDurationMillisecond,
			myFrameUPP,
			NULL,
			&nextFrameTimer);

	RunApplicationEventLoop();

I use timers a lot to drive my game and it works very well.

Good luck,

::ken::
www.angelfroggames.com

There's a fully working example here - with some other goodies: http://webpages.charter.net/utopiapl...rbonStruct.dmg

Thanks a lot for the help, everyone...

Just so you all don't think I'm crazy, here is a link to the docs that this code came from.

Goto:
http://developer.apple.com/documenta...ger/index.html

Then click "Carbon Event Manager Tasks," in the navigation bar, and then click "Installing Timers."

Thanks for the example and the tip... I'll be using a regular event timer now.