#ifndef _c_V_B_Ltask_h
#define _c_V_B_Ltask_h

	// ===========================================================================
	//	cVBLtask.cpp	   Version 1.2	©1998 Joakim Braun All rights reserved.
	// ===========================================================================
	//
	//	CONTENTS:	A base class for vertical retrace tasks (VBL tasks). Handles installing
	//			and removing of tasks. Subclass to add functionality.

	//	HOW TO USE:	Derive a class from cVBLtask. Override GotVBLResources() and DoVBLTask().
	//			Instantiate the object. VBL task lasts until object goes out of scope.

	//	cVBLtask is free for any and all use. 
	//	Do not distribute modified source code under my name.

	//	No support promised, no liability accepted. Provided "as is". 
	//	That said, I can be reached at braun@swipnet.se.

	//	Change history:
	//	1.1	March 30, 1997		First release
	//	1.2	August 30, 1998		Cleaned up code (gah!!) for re-release

	#include <Retrace.h>
	
	//************************
	// Dummy definition to get around recursion
	class cVBLtask;
	
	typedef struct {
		
		VBLTask 	theTask;
		long    	A5;
		cVBLtask*	vblObject;
	
	} VBLTaskWithA5AndObjectPtr, *smartVBLtaskPtr;
	
	
	class cVBLtask{
		
		public:
			cVBLtask(Int16 newVBLinterval);
			virtual ~cVBLtask(void);
			
		protected:
		
			void InstallVBLtask(void);
			void RemoveVBLtask(void);
			
			virtual void InitBeforeVBLinstall(void);
			virtual void CleanupAfterVBLremove(void);
			
			virtual Boolean GotVBLresources(void);
			virtual void DoVBLtask(void);			
			
		private:
			
			smartVBLtaskPtr	mTaskRecord;
			Int16           mVblInterval;
			Boolean			mTaskIsRunning;
			
			#if GENERATINGCFM
				static pascal void			VBLtask(VBLTaskPtr inVBLTaskPtr);
			#else
				static pascal void			VBLtask(VBLTaskPtr inVBLTaskPtr : __A0);
			#endif			
	};
	
	
#endif