/*

* Copyright (c) 2006-2007 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:   Definition of MHuiEventHandler, an interface enabling 

*                handling of scheduled events.

*

*/

#ifndef __HUIEVENTHANDLER_H__

#define __HUIEVENTHANDLER_H__

#include <e32base.h>

/* Forward declarations. */

class THuiEvent;

/**

 * MHuiEventHandler is an interface that can be derived by any object that want's to handle

 * Hitchcock UI Toolkit events scheduled by HuiScheduler.

 * 

 * If an object wishes to process events from the toolkit, it should implement this interface. 

 * 

 * @note   The destructor will NOT cancel any pending commands enqueued to this object,

 *         so you must call eg. <code>CHuiEnv::CancelCommands(this);</code> to cancel

 *         still pending commands to prevent calling destroyed object.

 */

class MHuiEventHandler

    {

public:

    /** 

     * Destructor. 

     * 

     * @note   Will NOT cancel any pending commands scheduled to this object,

     *         so you must call eg. <code>CHuiEnv::CancelCommands(this);</code> to cancel

     *         still pending commands to prevent calling destroyed object.

     */    

    IMPORT_C virtual ~MHuiEventHandler();

    /**

     * Called when an input event is being offered to this object.

     * 

     * The implementation must ensure that the function returns EFalse if 

     * it does not do anything in response to the event, otherwise, other objects

     * may be prevented from receiving the event. If it is able to process the 

     * event it should return ETrue.

     *

     * @param aEvent  Event to be handled.

     *

     * @return  <code>ETrue</code>, if the event was handled.

     *          Otherwise <code>EFalse</code>.

     */

    virtual TBool OfferEventL(const THuiEvent& aEvent) = 0;

    };  

#endif  // __HUIEVENTHANDLER_H__