/*

* 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:  Thumb bar size and position adjustment.

*

*/

#ifndef C_FSSCROLLBARCLET_H

#define C_FSSCROLLBARCLET_H

#include <e32base.h>

#include "fsscrollbarset.h"

class CHuiDeckLayout;

/**

 * Scrollbar controlet.

 *

 * This class handles the logic and drawing of a scrollbar.

 * You pass in a series of visuals, and then the class will

 * resize them to reflect the state of the scrollbar.

 *

 *  @code

 *   ?good_class_usage_example(s)

 *  @endcode

 *

 *  @lib ?library

 *  @since S60 ?S60_version *** for example, S60 v3.0

 */

class CFsScrollbarClet : public CBase

    {

public:

    /**

     * Constructor.

     */

    CFsScrollbarClet();

    /**

    * Destructor.

    */

    virtual ~CFsScrollbarClet();

    /**

     * Set the scrollbar visuals.

     * The scrollbar is build from these images by changing their places.

     *

     * @param aLayout The parent layout, should be a layout containing the

     * entire scrollbar.

     * @param aThumb The thumb scrollbar of the controlet.

     */

    void SetVisuals( CHuiDeckLayout* aLayout, CHuiDeckLayout* aThumb );

    /**

     * Define the layout to use.

     *

     * @param aHorizontal <code>ETrue</code>, if this scrollbar use

     * horizontal layout. Otherwise, <code>EFalse</code> to use vertical

     * layout.

     */

    void SetHorizontal( TBool aHorizontal );

    /**

     * Set the visibility mode of this scrollbar.

     *

     * @param aMode New visibility mode.

     */

    void SetVisibleMode( TFsScrollbarVisibility aMode );

    /**

     * Resolve the current visibility mode.

     *

     * @return The current visibility mode.

     */

    TFsScrollbarVisibility VisibilityMode();

    /**

     * Resolve if this scrollbar is visible.

     *

     * @return <code>ETrue</code>, if this scrollbar is visible.

     * Otherwise, <code>EFalse</code> is returned and the scrollbar is not

     * visible.

     */

    TBool IsVisible();

    /**

     * Set the range of the scrollbar. Will not actually move the scrollbar

     * until Update() is called.

     *

     * @param aStart Smallest value the scrollbar position can be set to.

     * @param aEnd Largest value the scrollbar position can be set to.

     * @panic KErrArgument if  the minimum range value is bigger than the

     * maximum range value.

     */

    void SetRange( TInt aStart, TInt aEnd );

    /**

     * Resolve the minimum range value.

     *

     * @return Minimum range value.

     */

    TInt RangeStart();

    /**

     * Resolve the maximum range value.

     *

     * @return Maximum range value.

     */

    TInt RangeEnd();

    /**

     * Set the count of visible items.

     *

     * @param aThumbSpan Count of items visible at the same time.

     */

    void SetThumbSpan( TInt aThumbSpan );

    /**

     * Resolve the count of total items on the list.

     *

     * @return Count of the total visible items at a time.

     */

    TInt ThumbSpan();

    /**

     * Set the position of the scrollbar. Will not actually move the scrollbar

     * until Update() is called.

     *

     * @param aPos Index of the first item visible, i.e. the index of the

     * topmost item in a list box.

     */

    void SetPos( const TInt aPos );

    /**

     * Get the index of the first position.

     *

     * @return Index of the first item.

     */

    TInt Pos();

    /**

     * Set the height and width of the thumb item.

     *

     * @param aSize Height and the width of the thumb image.

     */

    void SetThumbSize( const TSize& aSize );

    /**

     * Resolve the thumb size.

     *

     * @return The thumb image size.

     */

    TSize ThumbSize();

    /**

     * Update scrollbar thumb positions.

     *

     * @param aLayoutTransitionTime How long the transition should take

     * visually, in milliseconds.

     */

    void Update( TInt aLayoutTransitionTime = 0 );

    /**

     * Inform that the custom bar image is used.

     */

    void EnableCustomBarImage();

    /**

     * Inform that the custom thumb image is used.

     */

    void EnableCustomThumbImage();

    /**

     * Adjust the scrollbar visual size. The visual constructs from three

     * visual which size relations need to be calculated when the parent

     * visual's size changes.

     *

     * @param aLayout Layout containing the three visuals.

     * @param aTarget Target size.

     * @param aLayoutTransitionTime How long the transition should take

     * visually, in milliseconds.

     */

    void AdjustSize( CHuiGridLayout* aLayout, TSize& aTarget, TInt aLayoutTransitionTime = 0 );

private:

    /**

     * Set to show or hide this component.

     *

     * @param aIsVisible <code>ETrue</code>, if this scrollbar is visible.

     * Otherwise, <code>EFalse</code> to hide this scrollbar.

     */

    void SetVisible( TBool aIsVisible );

private: // data

    /**

     * Main visual of the part.

     * Not own.

     */

    CHuiDeckLayout* iScrollbarLayout;

    /**

     * Thumb of the item.

     * Not own.

     */

    CHuiDeckLayout* iThumbLayout;

    /**

     * The current scrollbar position.

     */

    TInt iPos;

    /**

     * The minimum value of the scrollbar position.

      */

    TInt iStart;

    /**

     * The maximum value of the scrollbar position.

     */

    TInt iEnd;

    /**

     * The size of the visible area in scrollbar values.

     */

    TInt iThumbSpan;

    /**

     * The size of the thumb.

     */

    TSize iThumbSize;

    /**

     * The minimum size of the thumb.

     */

    TSize iMinThumbSize;

    /**

     * The scrollbar is vertical by default.

     */

    TBool iHorizontal;

    /**

     * Defines if the scrollbar is visible or hidden.

     */

    TBool iVisible;

    /**

     * The visibility mode of the scrollbar.

     */

    TFsScrollbarVisibility iVisibility;

    /**

     * Defines if the default or custom bar image is used.

     */

    TBool iUseDefaultBarImages;

    /**

     * Defines if the default or custom thumb image is used.

     */

    TBool iUseDefaultThumbImages;

    };

#endif // C_FSSCROLLBARCLET_H