/*

* Copyright (c) 2006-2007 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:   Base class for tasks which load thumbnails

*

*/

#ifndef C_GLXTNLOADTHUMBNAILTASK_H

#define C_GLXTNLOADTHUMBNAILTASK_H

#include "glxtntask.h"

#include "glxtnstd.h"

// Forward declarations

class CGlxtnFileInfo;

class CGlxtnFileUtility;

class CFbsBitmap;

class CImageDecoder;

class TGlxThumbnailRequest;

/**

 * Base class for tasks which load thumbnails.

 *

 * @author Dan Rhodes

 * @ingroup glx_thumbnail_creator

 */

NONSHARABLE_CLASS( CGlxtnLoadThumbnailTask ) : public CGlxtnClientTask

    {

public:

    /**

    * Destructor.

    */

    ~CGlxtnLoadThumbnailTask();

protected:  // From CGlxtnTask

	void DoCancel();

protected:

    /**

    * C++ default constructor.

    * @param aId Task type ID.

    * @param aRequestInfo Parameters for the thumbnail request.

    * @param aFileUtility File utility for use by the task.

    * @param aClient Client initiating the request.

    */

    CGlxtnLoadThumbnailTask( const TGlxtnTaskId& aId,

                            const TGlxThumbnailRequest& aRequestInfo,

                            CGlxtnFileUtility& aFileUtility,

                            MGlxtnThumbnailCreatorClient& aClient );

    /**

    * Symbian 2nd phase constructor.

    * @param aBitmapHandle Handle to bitmap in which to store the thumbnail.

    */

    void ConstructL( TInt aBitmapHandle );

    /**

    * Start asynchronous loading.

    * @param aStatus Request status for the asynchronous operation.

    * @return ETrue if an asynchronous operation has been started.

    */

    TBool LoadThumbnailL( TRequestStatus& aStatus );

    /**

    * Create bitmap from loaded thumbnail data.

    * @param aStatus Request status for the asynchronous operation.

    * @return ETrue if an asynchronous operation has been started.

    */

    TBool HandleLoadedThumbnailL( TRequestStatus& aStatus );

    /**

    * Start asynchronous decoding.  iDecoder should point to a valid decoder.

    * @param aStatus Request status for the asynchronous operation.

    * @param aScaleBitmap If true, scale the loaded bitmap close to

    *       requested size.

    */

    void DecodeThumbnailL( TRequestStatus& aStatus, TBool aScaleBitmap );

protected:

    enum TGeneratorState

        {

        EStateFetchingUri, EStateLoading, EStateDecodingThumbnail,

        EStateDecodingImage, EStateScaling, EStateFiltering

        };

    /** File utility */

    CGlxtnFileUtility& iFileUtility;

	/** Current state for task state machine */

    TGeneratorState iState;

    /** File information for item to thumbnail (owned) */

    CGlxtnFileInfo* iInfo;

    /** Requested thumbnail size */

    TSize iRequestedSize;

    /** Thumbnail image data (owned) */

    HBufC8* iThumbData;

    /** Thumbnail data format */

    TGlxImageDataFormat iFormat;

    /** Decoder to decode the thumbnail data (owned) */

    CImageDecoder* iDecoder;

    /** Bitmap to decode image into (owned) */

    CFbsBitmap* iThumbnail;

    /** DRM allowed flag passed from thumbnail request */

    TBool iDrmAllowed;

    };

#endif // C_GLXTNLOADTHUMBNAILTASK_H