/*

* ============================================================================

*  Name     : NestedAO.h

*  Part of  : Base Plugin

*

*  Description:

*       Class used to implement nested active object used to handle deletion

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

*  Version:

*

*  Copyright (C) 2010 Nokia Corporation.

*  This material, including documentation and any related

*  computer programs, is protected by copyright controlled by

*  Nokia Corporation. All rights are reserved. Copying,

*  including reproducing, storing,  adapting or translating, any

*  or all of this material requires the prior written consent of

*  Nokia Corporation. This material also contains confidential

*  information which may not be disclosed to others without the

*  prior written consent of Nokia Corporation.

* ============================================================================

*/

#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__