/*

* Copyright (c) 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:  Fade effect for a list component.

 *

*/

#ifndef C_FSFADEEFFECT_H

#define C_FSFADEEFFECT_H

//<cmail> SF

#include <alf/alfeventhandler.h>

//</cmail>

//////TOOLKIT CLASSES

class CAlfVisual;

class CAlfControl;

class MFsFadeEffectObserver;

/**

 *  Class used for fade in/out effects.

 *

 *  @lib 

 */

NONSHARABLE_CLASS(CFsFadeEffect): public CBase, public MAlfEventHandler

    {

public:

    /**

     * Two-phased constructor

     * 

     * @param aRoot Root visual/layout which of the opacity is controlled

     * @param aTime Speed of fade in/out effect. Time in miliseconds.

     * 

     * @return Pointer to the new fade effect object

     */

    static CFsFadeEffect* NewL(CAlfControl* aControl, CAlfVisual* aRoot, TInt aTime);   

    /**

     * Two-phased constructor

     * 

     * @param aObserver Observer which will receive events about state chages

     * @param aRoot Root visual/layout which of the opacity is controlled

     * @param aTime Speed of fade in/out effect. Time in miliseconds.

     * 

     * @return Pointer to the new fade effect object

     */

    static CFsFadeEffect* NewL(CAlfControl* aControl, MFsFadeEffectObserver* aObserver, 

        CAlfVisual* aRoot, 

        TInt aTime);

    /**

     * Launches fade in effect

     */

    void FadeIn();

    /**

     * Launches fade out effect

     */

    void FadeOut();

    /**

     * Sets duration (in miliseconds) of the fade effects.

     * @param aTime Fade effect's duration in milisecond. 

     */

    void SetTime(const TInt aTime);

    /**

     * Returns speed of the fade effect

     * 

     * @return Duratin of the fade effect in miliseconds.

     */

    TInt Time() const;    

public: //From MAlfEventHandler

    /**

     * From MAlfEventHandler

     * 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 TAlfEvent& aEvent);

private:

    /**

     * Constructor

     * 

     * @param aRoot Root visual/layout which of the opacity is controlled

     * @param aTime Speed of fade in/out effect. Time in miliseconds.

     * 

     */

    CFsFadeEffect(CAlfControl* aControl,CAlfVisual* aRoot, TInt aTime);

    /**

     * Constructor

     * 

     * @param aObserver Observer which will receive events about state chages

     * @param aRoot Root visual/layout which of the opacity is controlled

     * @param aTime Speed of fade in/out effect. Time in miliseconds.

     * 

     * @return Pointer to the new fade effect object

     */

    CFsFadeEffect(CAlfControl* aControl,MFsFadeEffectObserver* aObserver, 

        CAlfVisual* aRoot, 

        TInt aTime);

private:

    /**

     * Custom events that informs about ending a fade effect.

     */

    enum TCustomEvent

        {

        ECustomEventFadeInFinished = 200,

        ECustomEventFadeOutFinished

        };

private:

    /**

     * 

     */

    CAlfControl* iControl;

    /**

     * Root visual/layout which of the opacity is controlled

     * Not own.

     */

    CAlfVisual* iRoot;

    /**

     * Observer of fade eddects

     * Not own.

     */

    MFsFadeEffectObserver* iObserver;

    /**

     * Speed of fade in/out effects

     */

    TInt iTime;

    };

#endif //C_FSFADEEFFECT_H