// $Revision: 1.10 $
//------------------------------------------------------------------------------
//
// Copyright (C) 1994 Taligent, Inc. All rights reserved.
//
// Project:			ConcurrentActors
// File:			RefreshSubsystem.h
// Build/Version:	1.0.0
//
// Description:		The Refresh subsystem maintains a thread that decides when 
//					to refresh the screen. It enforces a maximum, regular frame 
//					rate. (If the operating system slows with other processes, 
//					the frame rate might fall below the maximum.)
//
//------------------------------------------------------------------------------
#ifndef TaligentSamples_REFRESHSUBSYSTEM
#define TaligentSamples_REFRESHSUBSYSTEM

class MRefreshable;
class TRefreshThread;

#ifndef Taligent_COLLECTIONS
#include <Taligent/Collections.h>
#endif
#ifndef Taligent_SYNCHRONIZATION
#include <Taligent/Synchronization.h>
#endif
#ifndef Taligent_NOTIFICATION
#include <Taligent/Notification.h>
#endif
#ifndef Taligent_BASEGEOMETRY
#include <Taligent/BaseGeometry.h>
#endif

#ifndef TaligentSamples_LOCALUTILITIES
#include "LocalUtilities.h"
#endif

class TGrafPort;			// The TGrafPort can be found in GrafPort.h.

//==============================================================================
// MRefreshable

class MRefreshable {
public:
							MRefreshable();
	virtual					~MRefreshable();
	
	virtual void			PreRefresh(const TTime& interval);
	virtual void			Draw(TGrafPort& port) const = 0;
	virtual void			PostRefresh(const TTime& interval);
};

//==============================================================================
// TRefreshThread

class TRefreshThread : public TPeriodicThread {
public:
	static const TTime&		kDefaultFrameRate;

							TRefreshThread(TGrafPort* port,
								const TTime& rate = kDefaultFrameRate);
	virtual					~TRefreshThread();

	virtual void			Add(MRefreshable* object);
	virtual MRefreshable*	Remove(MRefreshable& object);
	virtual void			RemoveAll();
	
	virtual void			SetBackground(MRefreshable* background);
	
	TInterest*				CreateRefreshInterest();

protected:
	virtual void			HandleIntervalPassed(const TTime& interval);
	virtual void			GetDelayInterval(TTime& interval) const;

private:
	static const TToken&	kRefreshToken;

	TGrafPort*				fPort;
	MRefreshable*			fBackground;
	TDequeOf<MRefreshable>	fObjects;
	TSeconds				fRefreshRate;
	TNotifier				fRefreshNotifier;
	TInterest				fRefreshInterest;
	
};

#endif