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
32namespace 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