/*

* 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:    Scrollbar

*

*/

#ifndef C_GLXSCROLLBAR_H

#define C_GLXSCROLLBAR_H

#include <e32base.h>

class MGlxScrollbarObserver;

class CAlfControl;

class CAlfLayout;

class CAlfAnchorLayout;

class CGlxTextureManager;

/**

 * CGlxScrollbar

 *

 * Class to handle controlling/drawing of scrollbar

 *

 * Example: Scrollbar required for list with 10 items, with 3 visible items

 * The first visible row is at position 0.

 * The position is always from 0 to (full length - 1).

 *

 * Client calls:

 *

 * SetFullLength(10)

 * SetVisibleLength(3)

 * SetPosition(0)

 *

 * @lib glxuiutilities.lib

 *

 * @author Michael Yip

 */

class CGlxScrollbar : public CBase

    {

public:

    /**

     * Two phase constructor

     *

     * @param aControl The Alf control

     * @param aParentLayout The Alf layout that owns this scrollbar

     */

    IMPORT_C static CGlxScrollbar* NewL(CAlfControl& aControl, CAlfLayout& aParentLayout);

    /**

     * Two phase constructor

     *

     * @param aControl The Alf control

     * @param aParentLayout The Alf layout that owns this scrollbar

     */

    IMPORT_C static CGlxScrollbar* NewLC(CAlfControl& aControl, CAlfLayout& aParentLayout);

    /**

     * Add an observer to observe scrollbar

     * Observers are notified if the scrollbar is scrollable

     *

     * @param aObserver The observer

     */

    IMPORT_C void AddObserverL(MGlxScrollbarObserver* aObserver);

    /**

     * Remove an observer

     *

     * @param aObserver The observer

     */

    IMPORT_C void RemoveObserver(MGlxScrollbarObserver* aObserver);

    /**

     * Sets the visible length of the scrollbar

     *

     * @param aVisibleLength The visible length

     */

    IMPORT_C void SetVisibleLength(TUint aVisibleLength);

    /**

     * Sets the full length of the scrollbar

     *

     * @param aFullLength The full length

     * @param aTransitionTime The transition time in milliseconds if any animation is required

     */

    IMPORT_C void SetFullLength(TUint aFullLength, TUint aTransitionTime = 0);

    /**

     * Sets the position of the first visible row in the full length

     *

     * @param aPosition The position

     * @param aTransitionTime The transition time in milliseconds if any animation is required

     */

    IMPORT_C void SetPosition(TUint aPosition, TUint aTransitionTime = 0);

    /**

     * Destructor

     */

    ~CGlxScrollbar();

private:

    /**

     * Constructor

     */

    CGlxScrollbar();

    /**

     * Two phase constructor

     *

     * @param aControl The Alf control

     * @param aParentLayout The Alf layout that owns this scrollbar

     */

    void ConstructL(CAlfControl& aControl, CAlfLayout& aParentLayout);

    /**

     * Set the textures for the visuals

     */

    void SetTexturesL();

    /**

     * Set the textures for the visuals in the background layout

     *

     * @param aTextureManager The texture manager for creating textures

     */

    void SetBackgroundTexturesL(CGlxTextureManager& aTextureManager);

    /**

     * Set the textures for the visuals in the thumb layout

     *

     * @param aTextureManager The texture manager for creating textures

     */

    void SetThumbTexturesL(CGlxTextureManager& aTextureManager);

    /**

     * Set the background or thumb layout anchors

     *

     * @param aLayout The anchor layout to set the anchors for

     */

    void SetAnchors(CAlfAnchorLayout& aLayout);

    /**

     * Update the scrollbar

     *

     * @param aTransitionTime The transition time in milliseconds if any animation is required

     */

    void Update(TUint aTransitionTime = 0);

    /**

     * Notify observers if the scrollbar is scrollable

     */

    void NotifyObservers();

private:

    /// The Alf layout for the scrollbar

    /// Ownership passed to parent layout

    CAlfLayout* iLayout;

    /// The visible length of the scrollbar

    TUint iVisibleLength;

    /// The full length of the scrollbar

    TUint iFullLength;

    /// The position of the first visible row in the full length

    TUint iPosition;

    /// Observers of the scrollbar

    RPointerArray<MGlxScrollbarObserver> iObservers;

    };

#endif // C_GLXSCROLLBAR_H