/*

* Copyright (c) 2004-2005 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:  

*     See class description below

*

*/

#ifndef __LANDMARKS_DB_EVENT_HANDLER_H__

#define __LANDMARKS_DB_EVENT_HANDLER_H__

#include "LandmarksDbObserver.h"

#include <e32base.h>

#include <EPos_Landmarks.h>

class CPosLandmarkDatabase;

class MLandmarksDbEventObserver;

/**

*  In the Landmark reference application there is only one instance of 

*  CLandmarksDbEventHandler. It is the only object observing the 

*  default landmark database directly. Other objects that want to observe the 

*  database must register to this object. When an event occurs this object 

*  broadcasts it to all registered observers.

*/

class CLandmarksDbEventHandler : public CActive

    {

    public: // Constructors and destructor

        /**

        * C++ constructor.

        *

        * @param aDb the database to observer

        */

        CLandmarksDbEventHandler(

            CPosLandmarkDatabase& aDb);

        /**

        * Destructor.

        */

        ~CLandmarksDbEventHandler();

    public: // New functions

        /**

        * AddObserverL registers a db observer.

        *

        * @param aObserver the observer to register

        */

        void AddObserverL(MLandmarksDbObserver* aObserver);

    protected: // from CActive

        /**

        * Handles an active object’s request completion event.

        */

        void RunL();

        /**

        * Implements cancellation of an outstanding request.

        */

        void DoCancel();

        /**

        * Handles a leave occurring in the request completion event 

        * handler RunL().

        *

        * @return KErrNone

        */

        TInt RunError(TInt aError);

    private:

        /**

        * Starts observing of db enevs

        */

        void ObserveEvents();

    private:

        //! The database to observe

        CPosLandmarkDatabase& iDb;

        //! A db event to be reported

        TPosLmEvent iEvent;

        //! An array of registered observers

        RPointerArray<MLandmarksDbObserver> iDbObservers;

    };

#endif // __LANDMARKS_DB_EVENT_HANDLER_H__