// Copyright (c) 2008-2009 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 WSGCEDEBUGSESSION_H_

#define WSGCEDEBUGSESSION_H_

#include <w32std.h>

#include <w32debug.h>

struct TWsDebugWindowId;

class RWsDebugSession:public RWsSession

	{

public:

	RWsDebugSession(TInt aScreenNo = -1);

	~ RWsDebugSession();

	using RWsSession::DebugInfo;		//exposes the following two functions:

//	TInt	DebugInfo(TInt aFunction, TInt aParam=0) const;

//	TInt	DebugInfo(TInt aFunction, TDes8& aReturnBuf, TInt aParam=0) const;

	/**	Returns an array of debug data about the specified object. 

	 *  The data is placed in the aHostBuffer 

	 * 	If data is returned, aReturnedObject points to the start of the returned data, and the return value is the number of DataType objects.

	 * 	If no data is returned, aReturnedObject is NULL.

	 *  If so the return code indicates an error code, or the required number of objects.

	 * 	The object index is specified using the masks and shifts in TWsDebugClassArgMask

	 *  Various error codes may be returned from the server, some of which may simply explain why no data is available.

	 * 	The client may return 

	 * 		KErrCancel to indicate that there is zero length of data

	 * 		KErrCorrupt if the size of the returned data is not an exact multiple of DataType.

	 * 	No other type checking is performed.  

	 **/

	template <class DataType>	// DataType may be TSurfaceId, TInt,TRect, TSurfaceConfiguration (not TRegion)

	TInt	DebugInfo(TWsDebugInfoFunc aFunction, TInt aObjectIndex, TDes8& aHostBuffer,const DataType*&aReturnedObject)const

	{

	return DebugInfo(aFunction,aObjectIndex,aHostBuffer,(const void*&)aReturnedObject,sizeof(DataType));

	}

	/**	Fills the region object with the specified debug information.

	 * 	If required the region is resized to fit the data, which may fail with KErrNoMemory

	 * 	The region will be forced to error state if an error code is returned.

	 * 	Other details: see overloads

	 **/

	TInt	DebugInfo(TWsDebugInfoFunc aFunction, TInt aObjectIndex, TRegion& aPreAllocatedReturnedRegion)const;

	/** Indicates the start of a "consistancy-critical-read" section and fetches the window list.

	 * 	Any number of debug commands can be fetched in the section, then client can check if the were interrupted by a server recalculation.

	 **/

	TInt	ResetUpdatedAndGetSurfaceWindowList (const TWsDebugWindowId*&);

	/** Indicates the start or end of a "consistancy-critical-read" section

	 * 	Any number of debug commands can be fetched in the section, then client can check if the were interrupted by a server recalculation.

	 * 	If this method returns ETrue then the data fetched since the start may be inconsistant, and should be refetched.

	 * 	This method may also be used as a dirty way of waiting for a deferred update to occur.

	 **/

	TBool	ResetUpdated();

	/**	Returns the screen number assigned when the stub was created. 

	 **/

	TInt DebugScreenNo()	{	return iScreenNo;	}

	/** Helper method to correctly format the aObjectIndex parameter.

	 **/

	inline TInt ObjInd(TInt aWin=0,TInt aLayer=0,TInt aExtra=0)

		{	return ObjIndScr(iScreenNo,aWin,aLayer,aExtra);	}

	/** Helper method to correctly format the aObjectIndex parameter.

	 **/

	inline TInt ObjIndScr(TInt aScreen,TInt aWin=0,TInt aLayer=0,TInt aExtra=0);

	inline	TInt Finish(TBool aAndFlush=ETrue)

		{

		if (aAndFlush)

			Flush();

		return RWsSession::Finish();

		}

protected:

	// Resolves the template parameter to a size. See overload docs for more info.

	TInt	DebugInfo(TWsDebugInfoFunc aFunction, TInt aObjectIndex, TDes8& aHostBuffer,const void*&aReturnedObject,TInt aSize)const;

	TInt	iScreenNo;

	TInt	iSurfaceUpdateSerial;

	RBuf8	iSurfaceListBuffer;

	};

inline TInt RWsDebugSession::ObjIndScr(TInt aScreen,TInt aWin,TInt aLayer,TInt aExtra)

	{

	return 	(aScreen<<EWsDebugArgScreenShift)

		|	(aWin<<EWsDebugArgWindowShift)

		|	(aLayer<<EWsDebugArgLayerShift)

		|	(aExtra<<EWsDebugArgExtraShift);

	}

#endif /*WSGCEDEBUGSESSION_H_*/