/*

* Copyright (c) 2010 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:  Class used to implement nested active object used to handle 

* deletion of large number of messages by breaking them into smaller chunks

*

*/

#ifndef __NESTED_AO_H__

#define __NESTED_AO_H__

//  Include Files

#include <e32base.h>

class MDeletionHandler

    {

public:

    enum TState

        {

        EInProgress,

        EFree

        };

    //Deletes messages from aStartIndex KSizeOfChunk at a time

    virtual TBool DeleteMessagesInChunksL( TInt aStartIndex ) = 0;

    };

//Time interval between issuing 2 requests to delete messages

const TInt KWaitIntervalInMicroSecs=500;

//Maximum number of messages deleted in one go

const TInt KSizeOfChunk=10;

NONSHARABLE_CLASS ( CNestedAO ) : public CTimer

    {

    public:

        static CNestedAO* NewL( MDeletionHandler& aDeletionHandler );

        virtual ~CNestedAO();

        // --------------------------------------------------------------------------

        // CNestedAO::DeleteMessagesAsync

        // Used to delete messages asynchronously 

        // Deleting a small number of messages at a time

        // ------------

        void DeleteMessagesAsync();

        // --------------------------------------------------------------------------

        // CNestedAO::Rc

        // Used to return the iStatus return value

        // ------------        

        TInt Rc() { return iRc; }

    private:

        CNestedAO( MDeletionHandler& aDeletionHandler );

        void ConstructL();

        // inherited from CActive

        virtual void RunL();

        virtual void DoCancel();

        // --------------------------------------------------------------------------

        // CNestedAO::Stop

        // Stops the scheduler from running

        // Called after all messages are processed

        // or in error condition

        // ------------           

        void Stop();

    private:

        CActiveSchedulerWait* iNestedWait;

        MDeletionHandler& iDeletionHandler;

        TInt iDeletionIndex;

        TInt iRc;

    };

#endif  //__NESTED_AO_H__