/*

* 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:  Operation base class.

*

*/

#ifndef CVTENGOPERATION_H

#define CVTENGOPERATION_H

//  INCLUDES

#include <e32base.h>

#include "vtengcommands.h"

// FORWARD DECLARATIONS

class CVtEngCommandHandler;

class CVtEngHandlerContainer;

class MVtEngOperationObserver;

/**

*  Operation base class.

*

*  @lib videoteleng

*  @since 2.6

*/

NONSHARABLE_CLASS( CVtEngOperation ) : public CBase

    {

    public: // constructor and destructors

        /**

        * two-phase constructor

        * @param aCommandId command id

        * @param aHandlers handler container

        * @param aObserver observer called back when operation is completed

        * @param aDelete if ETrue command deletes itself after completion

        */

        static CVtEngOperation* NewL(

            TVtEngCommandId aCommandId,

            CVtEngHandlerContainer& aHandlers,

            MVtEngOperationObserver& aObserver,

            TBool aDelete = ETrue );

        /**

        * Destructor

        */

        ~CVtEngOperation( );

    public: // new functions

        /**

        * Performs operations.

        * @return ETrue is operation is complete (i.e. sync).

        */

        virtual TBool ExecuteL( TDesC8* aParams );

        /**

        * Cancels pending command.

        * @return ETrue if cancelled was succesfull or there

        * is nothing to cancel.

        */

        TBool Cancel();

        /**

        * Returns command identifier.

        * @return command identifier

        */

        inline TVtEngCommandId Command() const;

        /**

        * Returns command parameter buffer.

        * @return parameter buffer

        */

        inline const TDesC8* Parameters() const;

        /**

        * Notifies observer on completion.

        * @param aResult Symbian OS error code

        */

        virtual void HandleOpComplete( const TInt aResult );

    protected: // new functions

        /**

        *

        */

        TBool OfferExecuteSyncL( TDesC8* aParams );

    protected:

        /**

        * c++ constructor

        */

        CVtEngOperation(

            TVtEngCommandId aCommandId,

            CVtEngHandlerContainer& aHandlers,

            MVtEngOperationObserver& aCommandHandler,

            TBool aDelete );

		/**

        * Handles asynchronous operation complete

        */

    	static TInt ASyncHandleOpComplete( TAny* aPtr );

    protected:

        // Command identifier

        const TVtEngCommandId   iCommand;

        // Handler container

        CVtEngHandlerContainer& iHandlers;

        // observer for command response

        MVtEngOperationObserver&   iObserver;

        // Parameter

        TDesC8*                 iParams;

        // Delete command when complete

        TBool                   iDelete;

		// Pointer to asynchronous callback

        CAsyncCallBack*         iAsyncCallback;

		// Asynchronous callback error identifier

        TInt                    iAsyncErr;

    };

/**

* Utility class for unpacking data type with descriptor data.

* @lib videoteleng

* @since 2.6

*/

template <class T>

class TVtEngOpParamUtil

    {

    public:

        /**

        * Sets parameter in aDes to aRef.

        */

        inline void static Set( T& aRef , const CVtEngOperation& aOp );

    };

#include    "CVtEngOperation.inl"

#endif      // CVTENGOPERATION_H

// End of File