1 /*

     2 * Copyright (c) 2006-2007 Nokia Corporation and/or its subsidiary(-ies). 

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:   Definition of MHuiEventHandler, an interface enabling 

    15 *                handling of scheduled events.

    16 *

    17 */

    18 

    19 

    20  

    21 #ifndef __HUIEVENTHANDLER_H__

    22 #define __HUIEVENTHANDLER_H__

    23 

    24 #include <e32base.h>

    25 

    26 /* Forward declarations. */

    27 class THuiEvent;

    28 

    29 /**

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

    31  * Hitchcock UI Toolkit events scheduled by HuiScheduler.

    32  * 

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

    34  * 

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

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

    37  *         still pending commands to prevent calling destroyed object.

    38  */

    39 class MHuiEventHandler

    40     {

    41 public:

    42 

    43     /** 

    44      * Destructor. 

    45      * 

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

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

    48      *         still pending commands to prevent calling destroyed object.

    49      */    

    50     IMPORT_C virtual ~MHuiEventHandler();

    51 

    52     /**

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

    54      * 

    55      * The implementation must ensure that the function returns EFalse if 

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

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

    58      * event it should return ETrue.

    59      *

    60      * @param aEvent  Event to be handled.

    61      *

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

    63      *          Otherwise <code>EFalse</code>.

    64      */

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

    66 

    67     };  

    68 

    69 #endif  // __HUIEVENTHANDLER_H__