/*

* Copyright (c) 2008 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:  Implementation for presence cache reader notification handling

*

*/

#ifndef PRESENCECACHECLIENTNOTIFICATION_H

#define PRESENCECACHECLIENTNOTIFICATION_H

#include "presencecacheclient.h"

#include "presencecachedefs.h"

#include "presenceapiobjbase.h"

/**

 * Implementation for presence cache reader notification. This object is 

 * instantiated by CPresenceCacheClient. This class handles client-server

 * messaging for notifications.

 *

 * @ingroup ximpprescacheapi

 * @since S60 v5.0

 */

 NONSHARABLE_CLASS( CPresenceCacheClientNotification ) : public CActive

    {

public:

        /**

        * Two-phased constructor.

        * @param aClient presence cache client

        */

        static CPresenceCacheClientNotification* NewL( CPresenceCacheClient& aClient );

        /**

        * Destructor.

        */

        virtual ~CPresenceCacheClientNotification();

        /**

         * Subscribe for given presence buddy's change in presence. 

         *

         * @param aIdentity buddy id, in xsp format

         * @return KErrNone if successful, KErrArgument if observer not set

         * @leave Only in system error cases e.g. if failed to allocate memory.

         */

        TInt SubscribePresenceBuddyChangeL(const MXIMPIdentity& aIdentity);   

        /**

         * Unsubscribe for given presence buddy's change in presence. 

         *

         * @param aIdentity buddy id, in xsp format

         * @leave Only in system error cases e.g. if failed to allocate memory.

         */

        void UnsubscribePresenceBuddyChangeL(const MXIMPIdentity& aIdentity);          

private:

    /**

    * C++ constructor

    */

    CPresenceCacheClientNotification( CPresenceCacheClient& aClient );

    /**

    * Symbian second phase constructor

    */

    void ConstructL();

    void StartNotifySubscription();

    /**

     * Client callback handler Accesor 

     */

    MPresCacheReadHandler* ClientNotifyHandler(); 

    /**

     * Get presence from Cache server to a client observer

     * @param aClient client callback observer

     * @param aSize notification size

     */

    void PreseneceFromServerToClientL( MPresCacheReadHandler& aClient, TInt aSize );

public:  //From CActive

    void RunL();

    void DoCancel();

    TInt RunError( TInt aError );

private: // Data

        /**

         * presence cache client handling client-server messages

         */

        CPresenceCacheClient& iClient;

        /**

         * Size of presence notification for client-sever messages

         */

        TPckgBuf<TInt> iSizePckg;  

        /**

         * Whether the first notification subscription is done

         */

        TBool iNotificationSubscribed;

    };

#endif // PRESENCECACHECLIENTNOTIFICATION_H