/*

* Copyright (c) 2006-2009 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:

*

*/

/**

 @file

 @internalTechnology 

*/

#ifndef HWRMPSCHANGEOBSERVER_H

#define HWRMPSCHANGEOBSERVER_H

// INCLUDES

#include <e32base.h>

#include <e32property.h>

// FORWARD DECLARATIONS

// None

/**

*  An interface the developer implements for handling notification events. 

*

*/

class MHWRMPSChangeObserver

    {    

    public:

        /** 

        * Called when the PS value changes.

        * Note that if the value changes

        * very rapidly, some state transitions might be missed.

        * It is however guaranteed that latest state is always obtained.

        *

        * @param aUid Uid of the changed property

        * @param aKey Property identifier

        * @param aValue Indicates latest value

		*/

        virtual void PSValueChanged(const TUid& aUid, TUint32 aKey, TInt aValue) = 0;

	};

/**

* Active object wrapper for Publish and Subscribe one-shot notification handling.

* Listens for changes in light status and notifies the client.

*

*/

class CHWRMPSChangeObserver : public CActive

    {

    public:

        /**

        * This is a two-phase constructor method that is used to

        * create a new instance of CHWRMPSChangeObserver.

        * A newly created instance immediately starts listening to PS value changes.

        *

        * @param aCallback Reference to a callback instance.

        * @param aUid Uid of the changed property

        * @param aKey Property identifier

        * @return          A pointer to a new instance of the CHWRMPSChangeObserver class.

        */

        static CHWRMPSChangeObserver* NewL(MHWRMPSChangeObserver& aCallback,

                                      const TUid& aUid,

                                      TUint32 aKey);

        /**

        * This is a two-phase constructor method that is used to

        * create a new instance of CHWRMPSChangeObserver.

        * A newly created instance immediately starts listening to PS value changes.

        * Leaves the constructed instance to cleanup stack. 

        *

        * @param aCallback Reference to a callback instance.

        * @param aUid Uid of the changed property

        * @param aKey Property identifier

        * @return          A pointer to a new instance of the CHWRMPSChangeObserver class.

        */

        static CHWRMPSChangeObserver* NewLC(MHWRMPSChangeObserver& aCallback,

                                      const TUid& aUid,

                                      TUint32 aKey);

        /**

        * Destructor.

        */

        virtual ~CHWRMPSChangeObserver();

    protected:

        // From CActive

        void RunL();

        TInt RunError(TInt aError);

        void DoCancel();

    private:

        /**

        * Constructor

        *

        * @param aCallback Reference to a callback instance.

        * @param aUid Uid of the changed property

        * @param aKey Property identifier

        */

        CHWRMPSChangeObserver(MHWRMPSChangeObserver& aCallback,

                              const TUid& aUid,

                              TUint32 aKey);

        /**

        * By default Symbian 2nd phase constructor is private.

        */

        void ConstructL();

        /*

        * Order notification

        */

        void OrderNotification();

    private:

        MHWRMPSChangeObserver& iCallback;       // not owned by this class

        RProperty              iProperty;       // P&S property

        TUid                   iUid;            // Uid of the property

        TUint32                iKey;            // Property identifier

    };

#endif      // HWRMVIBRASTATUSOBSERVER_H

// End of File