/*

* 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:   Events generated by scrollers.

*

*/

#ifndef T_ALFSCROLLEREVENT_H

#define T_ALFSCROLLEREVENT_H

#include <e32std.h>

/**

 * ScrollerEvent class.

 * Usage:

 * @code

 * 

 * TBool CMyControl::OfferEventL(const TAlfEvent& aEvent)

 *   {

 *   TBool consumed(EFalse);

 *   if ( aEvent.IsPointerEvent() )

 *       {

 *       CAlfVisual* visual = aEvent.Visual();

 *       //Orientation for scroller

 *       TAlfScrollerEvent::TOrientation orientation = TAlfScrollerEvent::EVertical;

 *       

 *       if ( aEvent.PointerDown() )

 *           {

 *           //if ( some condition to start scroller event handling )

 *               {

 *               //Create event instance

 *               TAlfScrollerEvent scrollEvent(TAlfScrollerEvent::EMoveByItem, orientation, -1);

 *               TAlfEvent event( *(visual->Display()), scrollEvent );

 *               //Pass it to handler

 *               scrollerInputHandler->OfferEventL( event ); 

 *               consumed = ETrue;

 *               }

 *           }

 *        }

 *    return consumed;

 *    }

 * @endcode

 * @lib alfclient.lib

 * @since S60 xxx

 */

NONSHARABLE_CLASS( TAlfScrollerEvent )

    {

public:

    /**

     * Indicates what type of scroller the event originated in

     */

    enum TOrientation

        {

        EVertical,

        EHorizontal

        };

    /** 

     *Scroller event code

     */

    enum TCode

        {

        EMoveByItem, // Moves the view by a single logical unit. i.e. a text line or a list item

        EMoveByView, // Moves the view by an amount similar to a view height/width

        EMoveToPosition // Moves the view top to the requested position

        };

public: 

    /* Constructors. */

    /**

     * Constructor.

     */

    IMPORT_C TAlfScrollerEvent( TCode aCode, TOrientation aOrientation, TInt aMagnitude );

    /**

     * Constructor.

     *

     * Supplied only for default construction within TAlfEvent

     */

    TAlfScrollerEvent();

public: // Access methods

    /**

     * @return the event code for the scroller event

     */

    IMPORT_C TCode Code() const;

    /**

     * Orientation of the scroller

     *

     * @return orientation of the scroller generating this event

     */

    IMPORT_C TOrientation Orientation() const;

    /**

     * Access to the size of the scroller event.

     *

     * This magnitude represents the number of items, views, or other event code-dependent quantity

     *

     * For EMoveByItem, this number is the number of items to move forward. If negative, then it represents 

     * moving the view backward by this number of items.

     *

     * For EMoveByView, this number is the number of views forward to move.

     *

     * For EMoveToPosition, this number is in the arbitrary units of the associated scroller model. (i.e,.in order to

     * generate this type of event you must be observing the corresponding @c MAlfScrollerModelReader )

     *

     *  @return the magnitude of the event

     */

    IMPORT_C TInt Magnitude() const;

private: 

    /** 

     * The scroller event code. 

     */

    TCode iCode;

    /**

     * Orientation of this scroller

     */

    TOrientation iOrientation;    

    /**

     * A magnitude representing the number of items, views, or other code-dependent quantity

     * @see Magnitude()

     */

    TInt iMagnitude;

    TInt iSpare;    

    };

#endif // T_ALFSCROLLEREVENT_H