/*

* Copyright (c) 2002 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: 

*       Class for scaling bitmaps for the thumbnail control.

*

*/

#ifndef __CPbkThumbnailScaler_H__

#define __CPbkThumbnailScaler_H__

// INCLUDES

#include <e32base.h>

// FORWARD DECLARATIONS

class CFbsBitmap;

class CBitmapScaler;

/**

 * Observer interface for the scaling process.

 */

NONSHARABLE_CLASS(MPbkThumbnailScalerObserver) 

    {

    public:

        /**

         * Called when the thumbnail scaling completes.

         * @param aError KErrNone if the scaling was done successfully,

         *               otherwise one of the system wide error codes.

         * @param aBitmap Result of the scaling operation

         *                callee takes the ownership.

         */

        virtual void ThumbnailScalingComplete

            (TInt aError, CFbsBitmap* aBitmap) = 0;

    };

/**

 * Class for scaling bitmaps for the thumbnail control.

 */

NONSHARABLE_CLASS(CPbkThumbnailScaler) : 

        public CActive

    {

    public:

        /**

         * Static 2-phased constructor.

         * @param aObserver Observer for the scaling process.

         * @return Newly created instance of CPbkThumbnailScaler.

         */

        static CPbkThumbnailScaler* NewL

            (MPbkThumbnailScalerObserver& aObserver);

        /**

         * Standard C++ destructor.

         */

        ~CPbkThumbnailScaler();

    public: // interface

        /**

         * Creates thumbnail from the givan bitmap.

         * @param aBitmap Bitmap that will be converted to thumbnail.

         *                This class takes ownership of the bitmap.

         */

        void CreateThumbnail(CFbsBitmap* aBitmap);

    private: // From CActive

        void RunL();

        void DoCancel();

        TInt RunError(TInt aError);

    private: // Implementation

        /**

         * C++ constructor.

         * @param aObserver Observer for the scaling process.

         */

        CPbkThumbnailScaler(MPbkThumbnailScalerObserver& aObserver);

        /**

         * Starts the scaling process.

         * @param aBitmap The bitmap to be scaled.

         * @param aSize Target size of the bitmap.

         */

        void StartScaleL(CFbsBitmap* aBitmap, const TSize& aSize);

        /**

         * Crops the bitmap if needed.

         * @param aBitmap Bitmap to be cropped.

         */

        void DoCropL(CFbsBitmap* aBitmap);

    private: // Data

        /// Ref: Observer for the scaling process.

        MPbkThumbnailScalerObserver& iObserver;

        /// Own: Bitmap scaler

        CBitmapScaler* iScaler;

        /// Own: The bitmap that is scaled.

        CFbsBitmap* iBitmap;

    };

#endif // __CPbkThumbnailScaler_H__