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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 "platform/image-decoders/ImageDecoder.h"
30 #include "wtf/Noncopyable.h"
31 #include "wtf/OwnPtr.h"
32 
33 namespace WebCore {
34 
35 class PNGImageReader;
36 
37 // This class decodes the PNG image format.
38 class PLATFORM_EXPORT PNGImageDecoder : public ImageDecoder {
39     WTF_MAKE_NONCOPYABLE(PNGImageDecoder);
40 public:
41     PNGImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption, size_t maxDecodedBytes);
42     virtual ~PNGImageDecoder();
43 
44     // ImageDecoder
filenameExtension()45     virtual String filenameExtension() const OVERRIDE { return "png"; }
46     virtual bool isSizeAvailable() OVERRIDE;
hasColorProfile()47     virtual bool hasColorProfile() const OVERRIDE { return m_hasColorProfile; }
48     virtual ImageFrame* frameBufferAtIndex(size_t) OVERRIDE;
49     // CAUTION: setFailed() deletes |m_reader|.  Be careful to avoid
50     // accessing deleted memory, especially when calling this from inside
51     // PNGImageReader!
52     virtual bool setFailed() OVERRIDE;
53 
54     // Callbacks from libpng
55     void headerAvailable();
56     void rowAvailable(unsigned char* rowBuffer, unsigned rowIndex, int interlacePass);
57     void pngComplete();
58 
isComplete()59     bool isComplete() const
60     {
61         return !m_frameBufferCache.isEmpty() && (m_frameBufferCache.first().status() == ImageFrame::FrameComplete);
62     }
63 
64 private:
65     // Decodes the image.  If |onlySize| is true, stops decoding after
66     // calculating the image size.  If decoding fails but there is no more
67     // data coming, sets the "decode failure" flag.
68     void decode(bool onlySize);
69 
70     OwnPtr<PNGImageReader> m_reader;
71     bool m_doNothingOnFailure;
72     bool m_hasColorProfile;
73 };
74 
75 } // namespace WebCore
76 
77 #endif
78