1 /*

     2 * Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies). 

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:  Image Decoder class and observer interface.

    15 *

    16 */

    17 

    18 

    19 #ifndef CAM_IMAGEDECODER_H

    20 #define CAM_IMAGEDECODER_H

    21 

    22 // ===========================================================================

    23 // Included headers

    24 #include <e32std.h>

    25 #include <f32file.h>

    26 

    27 // ===========================================================================

    28 // Forward declarations

    29 class CFbsBitmap;

    30 class CImageDecoder;

    31 class MCameraBuffer;

    32 class CCamBufferShare;

    33 

    34 

    35 // ===========================================================================

    36 // Classes

    37 

    38 /**

    39 * Interface for Image Decoder Observers

    40 */

    41 class MCamImageDecoderObserver

    42   {

    43   public:

    44   

    45     /**

    46     * Notify observer that the image decoding has finished.

    47     * @param aStatus Status code describing the success of the operation.

    48     *        KErrNone if all went as planned.

    49     * @param aBitmap Decoded bitmap. NULL if errors in decoding.

    50     */

    51     virtual void ImageDecoded( TInt aStatus, const CFbsBitmap* aBitmap ) = 0;

    52 

    53   };

    54   

    55 

    56 /**

    57 * Image Decoder class

    58 */

    59 class CCamImageDecoder : public CActive

    60   {

    61   // =======================================================

    62   public:

    63 

    64     /**

    65     * 2-phase constructor.

    66     */

    67     static CCamImageDecoder* NewL( MCamImageDecoderObserver& aObserver );

    68     

    69     /**

    70     * Destructor.

    71     */

    72     virtual ~CCamImageDecoder();

    73 

    74   // -------------------------------------------------------

    75   // From CActive

    76   protected: 

    77 

    78     /**

    79     * Called when Cancel is requested and this AO is active.

    80     * @see CActive

    81     */

    82     virtual void DoCancel();

    83 

    84     /**

    85     * We get notified of the decoding success by a call to RunL

    86     * when decoding finishes.

    87     * @see CActive

    88     */

    89     virtual void RunL();

    90     

    91     /**

    92     * If a leave occurs in RunL, RunError gets called by the 

    93     * Active Scheduler.

    94     * @param aError Leave code from RunL.

    95     * @see CActive

    96     */

    97     virtual TInt RunError( TInt aError );

    98 

    99   // -------------------------------------------------------

   100   public:

   101 

   102     void StartConversionL( CCamBufferShare* aBuffer );

   103 

   104   private:

   105 

   106     /**

   107     * Store the buffer and release any previous buffer.

   108     * Can be called with NULL to release current buffer.

   109     */  

   110     void SetImageData( CCamBufferShare* aBuffer );

   111 

   112     /**

   113     * Get the image data in descriptor form.

   114     * No new memory is allocated to the returned buffer,

   115     * so ownership not transferred.

   116     * @return Pointer to image data that is to be used for image conversion.

   117     *         If EXIF thumbnail is available, it is used, otherwise the

   118     *         full image data is used instead. If the image data cannot be

   119     *         read from the buffer, or the buffer has not been set,

   120     *         leave will occur.

   121     * @leave  KErrNotFound, if image buffer is not set or contains no image data. 

   122     *         Any other system error, e.g. KErrNoMemory.

   123     */

   124     TDesC8* GetImageDataL();

   125 

   126     /**

   127     * Read the EXIF thumbnail and return it in descriptor.

   128     * If any errors, return NULL.

   129     * @param  aExifData The full image data containing EXIF part.

   130     * @return The EXIF thumbnail in a heap descriptor. NULL if

   131     *         error occurs in reading (OOM, no data given, 

   132     *         no EXIF thumbnail found..).

   133     */

   134     HBufC8* ReadExifThumbNail( const TDesC8& aExifData );

   135 

   136   private:

   137 

   138     /**

   139     * 2nd phase constructor.

   140     */

   141     void ConstructL();

   142 

   143     /**

   144     * 1st phase constructor.

   145     * Cannot leave.

   146     */

   147     CCamImageDecoder( MCamImageDecoderObserver& aObserver );

   148 

   149   // =======================================================

   150   // Data

   151   private:

   152 

   153     RFs                       iFs;

   154     MCamImageDecoderObserver& iObserver;

   155     

   156 

   157     CCamBufferShare* iSharedImageData;

   158     HBufC8*          iThumbnailData;

   159 

   160     CFbsBitmap*    iDecodedBitmap;

   161     CImageDecoder* iDecoder;    

   162     

   163     TInt           iRetryCounter;

   164 

   165   // =======================================================

   166   };

   167 

   168 // ===========================================================================

   169 #endif

   170 

   171 // end of file