1/*
2 * Copyright (c) 2008, 2009, Google Inc. All rights reserved.
3 *
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5 * modification, are permitted provided that the following conditions are
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7 *
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9 * notice, this list of conditions and the following disclaimer.
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12 * in the documentation and/or other materials provided with the
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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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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#pragma once
32
33#include "BMPImageReader.h"
34
35namespace WebCore {
36
37// This class decodes the BMP image format.
38class BMPImageDecoder final : public ScalableImageDecoder {
39public:
40 static Ref<ScalableImageDecoder> create(AlphaOption alphaOption, GammaAndColorProfileOption gammaAndColorProfileOption)
41 {
42 return adoptRef(*new BMPImageDecoder(alphaOption, gammaAndColorProfileOption));
43 }
44
45 // ScalableImageDecoder
46 String filenameExtension() const final { return "bmp"_s; }
47 void setData(SharedBuffer&, bool allDataReceived) final;
48 ScalableImageDecoderFrame* frameBufferAtIndex(size_t index) final;
49 // CAUTION: setFailed() deletes |m_reader|. Be careful to avoid
50 // accessing deleted memory, especially when calling this from inside
51 // BMPImageReader!
52 bool setFailed() final;
53
54private:
55 BMPImageDecoder(AlphaOption, GammaAndColorProfileOption);
56 void tryDecodeSize(bool allDataReceived) final { decode(true, allDataReceived); }
57
58 inline uint32_t readUint32(int offset) const
59 {
60 return BMPImageReader::readUint32(m_data.get(), m_decodedOffset + offset);
61 }
62
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, bool allDataReceived);
67
68 // Decodes the image. If |onlySize| is true, stops decoding after
69 // calculating the image size. Returns whether decoding succeeded.
70 bool decodeHelper(bool onlySize);
71
72 // Processes the file header at the beginning of the data. Sets
73 // |*imgDataOffset| based on the header contents. Returns true if the
74 // file header could be decoded.
75 bool processFileHeader(size_t* imgDataOffset);
76
77 // An index into |m_data| representing how much we've already decoded.
78 // Note that this only tracks data _this_ class decodes; once the
79 // BMPImageReader takes over this will not be updated further.
80 size_t m_decodedOffset;
81
82 // The reader used to do most of the BMP decoding.
83 std::unique_ptr<BMPImageReader> m_reader;
84};
85
86} // namespace WebCore
87