/*

* Copyright (c) 2003-2009 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: 

* CContactDbEventQueue Test module

*

*/

#ifndef __CContactDbEventQueue_H__

#define __CContactDbEventQueue_H__

// INCLUDES

#include <cntdef.h>

#include <cntdbobs.h>

#include "cfixedqueue.h"

// CLASS DECLARATION

class CContactChangeNotifier;

class CContactDatabase;

/**

 * Contact Engine event queue class.

 */ 

class CContactDbEventQueue : 

        public CTimer, public MContactDbObserver

    {

    public:

        /**

         * Creates a new event queue.

         * @param aDb   contact DB to listen for events.

         * @param aMaxQueueSize maximum size of event queue.

         * @return a new instance of this class.

         */

        static CContactDbEventQueue* NewL

            (CContactDatabase* aDb=NULL, TInt aMaxQueueSize=128);

        ~CContactDbEventQueue();

        /**

         * Waits for an event from the database.

         * @param aTimeOut  max time to wait for an event.

         * @param aEvent    the received event, undefined if this function returns false.

         * @return true if an event was received, false if timeout expired first.

         */

        TBool ListenForEvent

            (TTimeIntervalSeconds aTimeOut, 

            TContactDbObserverEvent& aEvent);

         /**

         * Pops Events from the event queue.  Required to avoid filling the queue.

         */    

        void PopEvent();           

         /**

         * Pops All Events from the event queue. Required to avoid queue overflow.

         */    

		void Clear();

        /**

         * Removes all previously arrived events from the queue.

         */

        inline void Flush()

            {

            iQueue.Reset();

            }

    protected: // From MContactDbObserver.

	    void HandleDatabaseEventL(TContactDbObserverEvent aEvent);

    private:  

        void RunL(); // from CTimer

        CContactDbEventQueue();

        void ConstructL(CContactDatabase* aDb, TInt aMaxQueueSize);

    private:  

        /// Own: the notifier for attaching to CContactDatabase

        CContactChangeNotifier* iNotifier;

        /// Own: event queue array

        CFixedQueue<TContactDbObserverEvent> iQueue;

    };

#endif  // __CContactDbEventQueue_H__