1/*
2 * Copyright (c) 2008, 2009, Google 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 are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
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15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef BMPImageDecoder_h
32#define BMPImageDecoder_h
33
34#include "platform/image-decoders/bmp/BMPImageReader.h"
35#include "wtf/OwnPtr.h"
36
37namespace blink {
38
39// This class decodes the BMP image format.
40class PLATFORM_EXPORT BMPImageDecoder : public ImageDecoder {
41public:
42    BMPImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption, size_t maxDecodedBytes);
43
44    // ImageDecoder
45    virtual String filenameExtension() const OVERRIDE { return "bmp"; }
46    virtual void setData(SharedBuffer*, bool allDataReceived) OVERRIDE;
47    virtual bool isSizeAvailable() OVERRIDE;
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    // BMPImageReader!
52    virtual bool setFailed() OVERRIDE;
53
54private:
55    inline uint32_t readUint32(int offset) const
56    {
57        return BMPImageReader::readUint32(m_data.get(), m_decodedOffset + offset);
58    }
59
60    // Decodes the image.  If |onlySize| is true, stops decoding after
61    // calculating the image size. If decoding fails but there is no more
62    // data coming, sets the "decode failure" flag.
63    void decode(bool onlySize);
64
65    // Decodes the image.  If |onlySize| is true, stops decoding after
66    // calculating the image size. Returns whether decoding succeeded.
67    bool decodeHelper(bool onlySize);
68
69    // Processes the file header at the beginning of the data.  Sets
70    // |imgDataOffset| based on the header contents. Returns true if the
71    // file header could be decoded.
72    bool processFileHeader(size_t& imgDataOffset);
73
74    // An index into |m_data| representing how much we've already decoded.
75    // Note that this only tracks data _this_ class decodes; once the
76    // BMPImageReader takes over this will not be updated further.
77    size_t m_decodedOffset;
78
79    // The reader used to do most of the BMP decoding.
80    OwnPtr<BMPImageReader> m_reader;
81};
82
83} // namespace blink
84
85#endif
86