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      1 /*
      2  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #ifndef PNGImageDecoder_h
     27 #define PNGImageDecoder_h
     28 
     29 #include "ImageDecoder.h"
     30 #include <wtf/OwnPtr.h>
     31 
     32 namespace WebCore {
     33 
     34     class PNGImageReader;
     35 
     36     // This class decodes the PNG image format.
     37     class PNGImageDecoder : public ImageDecoder {
     38     public:
     39         PNGImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption);
     40         virtual ~PNGImageDecoder();
     41 
     42         // ImageDecoder
     43         virtual String filenameExtension() const { return "png"; }
     44         virtual bool isSizeAvailable();
     45         virtual bool setSize(unsigned width, unsigned height);
     46         virtual ImageFrame* frameBufferAtIndex(size_t index);
     47         // CAUTION: setFailed() deletes |m_reader|.  Be careful to avoid
     48         // accessing deleted memory, especially when calling this from inside
     49         // PNGImageReader!
     50         virtual bool setFailed();
     51 
     52         // Callbacks from libpng
     53         void headerAvailable();
     54         void rowAvailable(unsigned char* rowBuffer, unsigned rowIndex, int interlacePass);
     55         void pngComplete();
     56 
     57         bool isComplete() const
     58         {
     59             return !m_frameBufferCache.isEmpty() && (m_frameBufferCache.first().status() == ImageFrame::FrameComplete);
     60         }
     61 
     62     private:
     63         // Decodes the image.  If |onlySize| is true, stops decoding after
     64         // calculating the image size.  If decoding fails but there is no more
     65         // data coming, sets the "decode failure" flag.
     66         void decode(bool onlySize);
     67 
     68         OwnPtr<PNGImageReader> m_reader;
     69         bool m_doNothingOnFailure;
     70     };
     71 
     72 } // namespace WebCore
     73 
     74 #endif
     75