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
33namespace blink {
34
35class PNGImageReader;
36
37// This class decodes the PNG image format.
38class PLATFORM_EXPORT PNGImageDecoder : public ImageDecoder {
39    WTF_MAKE_NONCOPYABLE(PNGImageDecoder);
40public:
41    PNGImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption, size_t maxDecodedBytes);
42    virtual ~PNGImageDecoder();
43
44    // ImageDecoder
45    virtual String filenameExtension() const OVERRIDE { return "png"; }
46    virtual bool isSizeAvailable() OVERRIDE;
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
59    bool isComplete() const
60    {
61        return !m_frameBufferCache.isEmpty() && (m_frameBufferCache.first().status() == ImageFrame::FrameComplete);
62    }
63
64private:
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 blink
76
77#endif
78