/*

* Copyright (c) 2008 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:   Drop shadow handler

*

*/

#ifndef C_HUIDROPSHADOW_H

#define C_HUIDROPSHADOW_H

#include <gdi.h>

#include <uiacceltk/HuiRealPoint.h>

#include <uiacceltk/HuiRealRect.h>

#include <uiacceltk/HuiTimedPoint.h>

#include <uiacceltk/HuiTextureHandle.h>

#include <uiacceltk/huimetric.h>

class TAknsItemID;

class MHuiSegmentedTexture;

class CHuiTexture;

class CHuiVisual;

/**

 *  Drop shadow parameter handler

 *

 *  This interface can be fetched from the visual

 *  @see CHuiVisual::EnableDropShadowL

 *  @see CHuiVisual::DropShadowHandler

 *  

 *  @code

 *   // get the pointer

 *   visual->EnableDropShadowL();

 *   CHuiDropShadow* dropShadow = visual->DropShadowHandler();

 *

 *   // use it

 *   dropShadow->SetColor( KRgbRed );

 *   dropShadow->iOffset.Set( THuiRealPoint( 10, 10 ) );

 *  @endcode

 *

 *  Disabling the drop shadow from the visual, deletes the instance and therefore loses

 *  all set paramteres. If you want to just hide the drops shadow temporally, you can 

 *   a) set the opacity into 0 or

 *   b) set the scale into 0

 *

 *  @lib hitchcock.lib

 *  @since S60 v5.0.1

 */

NONSHARABLE_CLASS( CHuiDropShadow ) : public CBase

    {

public: // Exported functions

    /**

     * Sets the shadow in polar coordinates. This will be converted into xy

     * coordinates

     *

     * @param aAngle Angle of the shadow. 0 degrees is on the right hand side and 90 in directly above.

     * @param aDistance Distance of the shadow in unit defined by the user component. 

     * @param aTransitionTime Time reach the target.

     */ 

    IMPORT_C void SetOffset( TReal32 aAngle, THuiMetric aDistance, TInt aTransitionTime = 0 ) __SOFTFP;

    /**

     * Sets the color of the shadow.

     *

     * @param aColor Text color.

     * @param aTransitionTime Time reach the target. (not supported )

     */

    IMPORT_C void SetColor(const TRgb& aColor, TInt aTransitionTime = 0 );

     /**

      * Sets the color of the shadow via skin id.

      *

      * @param aID      Skin ID of the color group to use

      * @param aIndex   Index within the color group

      * @param aTransitionTime Time reach the target. (not supported )

      */

     IMPORT_C void SetColor(const TAknsItemID& aID,const TInt aIndex, TInt aTransitionTime = 0 );

public: // internal methods

    CHuiDropShadow();

    void ConstructL();

    ~CHuiDropShadow();

    TBool Changed() const;

    void ClearChanged();

    TRgb Color() const;

    /**

     * Calculates the drawing size of the shadow texture

     *

     * @param aImageDrawingSize     Image drawing size

     * @param aShadowTextureSize    Shadow texture size

     *

     * @return Shadow drawing size

     */

    THuiRealSize ShadowDrawingSize( 

        const TSize& aImageDrawingSize, 

        const TSize& aShadowTextureSize ) const;

    /**

     * Checks if the shadow is visible (checks opacity and scale != 0)

     * 

     * @return ETrue if visible.

     */ 

    TBool IsShadowVisible() const;

    /**

     * Casts 'const MHuiTexture' into 'CHuiTexture' if applicaple.

     *

     * @param aTextureIf Original texture interface

     *

     * @return Casted to CHuiTexture instance if possible.

     */

    static CHuiTexture* ShadowedTextureInstance( const MHuiTexture& aTextureIf );

    /**

     * Calculates the shadow distance in pixels.

     *

     * @param aReferenceVisual Visual which determines the metrics.

     *

     * @return Shadow distance in pixels.

     */

    THuiRealPoint DistanceInPixels( const CHuiVisual& aReferenceVisual ) const;

    /**

     * Returns the rectangle in which the shadow is supposed to be drawn.

     * Area is given as real/floating values.

     *

     * @param aImageDrawingPosition Position where the image is drawn

     * @param aImageDrawingSize Size of the image to be drawn

     * @param aShadowTextureSize Size of the shadow texture

     * @prarm aReferenceVisual Reference visual for the relative metrics.

     *

     * @return Area used by the shadow.

     */

    THuiRealRect ShadowDrawingRealRect( 

        const TPoint& aImageDrawingPosition,

        const TSize& aImageDrawingSize, 

        const TSize& aShadowTextureSize,

        const CHuiVisual& aReferenceVisual  ) const;

    /**

     * Returns the rectangle in which the shadow is supposed to be drawn.

     * Area is given as integer/fixed values.

     *

     * @param aImageDrawingPosition Position where the image is drawn

     * @param aImageDrawingSize Size of the image to be drawn

     * @param aShadowTextureSize Size of the shadow texture

     * @prarm aReferenceVisual Reference visual for the relative metrics.

     *

     * @return Area used by the shadow.

     */    

    TRect ShadowDrawingTRect( 

        const TPoint& aImageDrawingPosition,

        const TSize& aImageDrawingSize, 

        const TSize& aShadowTextureSize,

        const CHuiVisual& aReferenceVisual  ) const;

public: // public members

    /**

     * Opacity of the shadow

     */ 

    THuiTimedValue iOpacity;

    /**

     * Shadow offset in timed xy-coordinates

     */

    THuiTimedPoint iOffset;

    /**

     * Shadow offset unit

     */

    TInt iOffsetUnit;

    /**

     * Sets the blur filter radius. This is used to generate the shadow from the

     * texture. Normally between 2-5 pixels (in texture coordinates).

     */

    THuiTimedValue iRadius;

    /**

     * Scale of the shadow - default 1.0.

     */ 

    THuiTimedValue iScale;

private:

    struct THuiDropShadowData;

    THuiDropShadowData* iData;

    };

#endif // C_HUIDROPSHADOW_H