/*

* Copyright (c) 2006 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:  Definition of the stream source reader active object class

*

*/

#ifndef DATACOPYENGINEAO_H

#define DATACOPYENGINEAO_H

// INCLUDES

#include <e32base.h>

class CSourceQueueItem;

class CSinkQueueItem;

class MDataCopyEngineObserver;

class CDataCopyEngineAO : public CActive

    {

    public: // Constructors and destructor

		/**

		* Two-phased constructor.

		*/

        static CDataCopyEngineAO* NewL( TSglQue<CSourceQueueItem>* aSourceQueue,

            TSglQue<CSinkQueueItem>* aSinkQueue,

            MDataCopyEngineObserver& aObserver );

		/**

		* Destructor.

		*/

        virtual ~CDataCopyEngineAO();

        // Called by DataBufferSource when a request is added to source queue

        void SourceQueueChanged();

        // Called by DataBufferSource when a request is added to sink queue

        void SinkQueueChanged();

        // Called by DataBufferSource to start the engine

        void Start();

        // Called by DataBufferSource to stop the engine

        void Stop();

        // Called by DataBufferSource to pause the engine

        void Pause();

        // Called by Active Object framework

        virtual void RunL();

        virtual void DoCancel();

        virtual TInt RunError(TInt aError);

    private:

    /**

    * C++ default constructor.

        */

        CDataCopyEngineAO( TSglQue<CSourceQueueItem>* aSourceQueue,

            TSglQue<CSinkQueueItem>* aSinkQueue,

            MDataCopyEngineObserver& aObserver );

            /**

            * By default Symbian 2nd phase constructor is private.

        */

        void ConstructL();

        // Used by this to keep the AO going

        void KickSignal();

    private:

        enum TDataCopyEngineState

            {

            EStopped,       // Stopped state

                EPaused,        // Paused state

                EExecuting,     // Copying data

                EWaitingForSourceQueueSignal,   // Waiting for item to be available in the source queue

                EWaitingForSinkQueueSignal

            };

        // Reference to Source queue passed in thru constructor

        TSglQue<CSourceQueueItem>*  iSourceQueue;

        // Reference to Sink queue passed in thru constructor

        TSglQue<CSinkQueueItem>*    iSinkQueue;

        // Reference to observer

        MDataCopyEngineObserver*    iObserver;

        // State of the engine

        TDataCopyEngineState        iState;

        // Holds true if source queue item is processed

        TBool                       iSourceQueueItemProcessed;

        // Holds true if sink queue item is processed

        TBool                       iSinkQueueItemProcessed;        

        // Temporary buffer containing data from source queue

        HBufC8*                     iSrcDataDes;

        // Data Position within the temporary buffer

        TInt                        iSrcDataPos;

    };

#endif      // DATACOPYENGINEAO_H

//  End of File