/*

* Copyright (c) 2002 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:  

*     This is a base class for implementing asyncronous item saving.

*

*/

#ifndef CMSGASYNCITEMSAVER_H

#define CMSGASYNCITEMSAVER_H

// INCLUDES

#include <e32base.h>

// CLASS DECLARATION

/**

* Interface for implementing the asyncronous saving operations.

*/

class MMsgAsyncItemSaver

    {

    public:

        /**

        * Checks the status of the operation.

        * @return ETrue if the operation can be completed, EFalse

        * if the operation should continue.

        */

        virtual TBool IsComplete() const = 0;

        /**

        * Perform some operations and set the inner state.

        * If this leaves then RunError will be called with the

        * leave code.

        */

        virtual void ContinueOperationL() = 0;

        /**

        * This method is called after IsComplete() has return ETrue.

        * This method should result deleting the saver object.

        */

        virtual void CompleteOperationL() = 0;

        /**

        * Error handling method. If a leave occurs in ContinueOperationL

        * then this method will be called with the leave code.

        * @param aError Error code from the leave.

        * @return Error code or KErrNone if error doesn't need to be

        * handled. Returning KErrNone will continue the operation.

        */

        virtual TInt HandleError( TInt aError ) = 0;

    };

/**

* This class implements the asyncronous framework for item saving.

*/

class CMsgAsyncItemSaver : public CActive

    {

    public: 

        /**

        * Constructor.

        */

        IMPORT_C CMsgAsyncItemSaver();

        /**

        * Destructor.

        */  

        IMPORT_C ~CMsgAsyncItemSaver();

        /**

         * Call this when the operation is ready to start executing.

         * Ownership of aItemSaver is not taken.

         * @param aItemSaver asyncronous item saver

         */

        IMPORT_C void StartOperation( MMsgAsyncItemSaver* aItemSaver );

		/**

		* @param aMicroseconds time to pause. By default pauses indefinitely.

		*/

		IMPORT_C void Pause( TInt aMicroSeconds = 0 );

		IMPORT_C void Continue();

    protected: // from CActive

        void RunL();

        void DoCancel();

	    TInt RunError(TInt aError);

    private: // Own

        /**

        * Execute the next loop.

        */

        void NextStep();

    private:

        /// Reference to the operation specific item saver.

        MMsgAsyncItemSaver* iItemSaver;

		/// Saver activity state.

		TBool iPaused;

		RTimer iTimer;

		TInt iPauseDelay;

    };

#endif // CMSGASYNCITEMSAVER_H

// End of file