/*

* Copyright (c) 2008-2009 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:    Provides a simple observable interface.

*

*/

#ifndef M_GLXSIMPLEOBSERVABLE_H

#define M_GLXSIMPLEOBSERVABLE_H

#include <e32base.h>

#include "glxsimpleobserverevents.h"

class MGlxSimpleObserver;

/**

 *  MGlxSimpleObservable

 *

 *  Provides a simple observable interface.

 *

 *  @lib glxhuiutils.lib

 */

class MGlxSimpleObservable

    {

public:

    /**

    * Registers an observer if not previously registered

    * @param aObserver The observer concerned

    */

    virtual void RegisterObserverL( MGlxSimpleObserver* aObserver ) = 0;

    /**

    * Deregisters an observer if previously registered

    * @param aObserver The observer concerned

    */

    virtual void DeregisterObserver( MGlxSimpleObserver* aObserver ) = 0;

    };

#endif // M_GLXSIMPLEOBSERVABLE_H