/*

* Copyright (c) 2004 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

#ifndef __TRKFRAMINGLAYER_H__

#define __TRKFRAMINGLAYER_H__

#include "TrkCommPort.h"

//

// Forward declarations

//

class CTrkDispatchLayer;

//

// class CTrkFramingLayer

//

// Frames outgoing messages to the host and unframes incoming messages

// from the host

//

class CTrkFramingLayer : public CBase

{

public:

	enum TFramingState

	{

		eWaiting,

		eFound,

		eInFrame,

		eFrameOverflow

	};

	CTrkFramingLayer(CTrkCommPort* aPort);

	~CTrkFramingLayer();

	void Listen(CTrkDispatchLayer* aDispatchLayer);

	void StopListening();

	void HandleByte(TUint8 aByte);

	void RespondOkL(const TDesC8& aMsg);

	void RespondErr(TUint8 aType, TUint8 aErr);

	void InformEventL(const TDesC8& aMsg);

	void SendRawMsgL(const TDesC8& aMsg);

	TBool IsBigEndian() { return iIsBigEndian; };

	void ResetSequenceIDs() { iSequenceId = 1; iOutSequenceId = 1; };

private:

	void SendMsgL(const TDesC8& aMsg);

	void DiscardFrame();

	TBool ProcessFrame();

	void IncrementSequenceId() { if (iSequenceId == 0xFF) iSequenceId = 1; else iSequenceId++; };

	void IncrementOutSequenceId() { if (iOutSequenceId == 0xFF) iOutSequenceId = 1; else iOutSequenceId++; };

private:

	CTrkCommPort* iPort;

	CTrkDispatchLayer* iDispatchLayer;

	TFramingState iFramingState;

	TBool iEscape;

	TUint8 iFCS;

	TBuf8<MAXMESSAGESIZE> iBuffer;	// contains the incoming messages

	TUint8 iSequenceId;

	TUint8 iOutSequenceId;

	TBool iIsBigEndian;

	HBufC8* iLastReply;

};

#endif // __TRKFRAMINGLAYER_H__