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      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.
     14  *     * Neither the name of Google Inc. nor the names of its
     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
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     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,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include "config.h"
     32 #include "platform/image-decoders/bmp/BMPImageDecoder.h"
     33 
     34 #include "platform/PlatformInstrumentation.h"
     35 #include "wtf/PassOwnPtr.h"
     36 
     37 namespace blink {
     38 
     39 // Number of bits in .BMP used to store the file header (doesn't match
     40 // "sizeof(BMPImageDecoder::BitmapFileHeader)" since we omit some fields and
     41 // don't pack).
     42 static const size_t sizeOfFileHeader = 14;
     43 
     44 BMPImageDecoder::BMPImageDecoder(ImageSource::AlphaOption alphaOption,
     45     ImageSource::GammaAndColorProfileOption gammaAndColorProfileOption,
     46     size_t maxDecodedBytes)
     47     : ImageDecoder(alphaOption, gammaAndColorProfileOption, maxDecodedBytes)
     48     , m_decodedOffset(0)
     49 {
     50 }
     51 
     52 void BMPImageDecoder::setData(SharedBuffer* data, bool allDataReceived)
     53 {
     54     if (failed())
     55         return;
     56 
     57     ImageDecoder::setData(data, allDataReceived);
     58     if (m_reader)
     59         m_reader->setData(data);
     60 }
     61 
     62 bool BMPImageDecoder::isSizeAvailable()
     63 {
     64     if (!ImageDecoder::isSizeAvailable())
     65         decode(true);
     66 
     67     return ImageDecoder::isSizeAvailable();
     68 }
     69 
     70 ImageFrame* BMPImageDecoder::frameBufferAtIndex(size_t index)
     71 {
     72     if (index)
     73         return 0;
     74 
     75     if (m_frameBufferCache.isEmpty()) {
     76         m_frameBufferCache.resize(1);
     77         m_frameBufferCache.first().setPremultiplyAlpha(m_premultiplyAlpha);
     78     }
     79 
     80     ImageFrame* buffer = &m_frameBufferCache.first();
     81     if (buffer->status() != ImageFrame::FrameComplete) {
     82         PlatformInstrumentation::willDecodeImage("BMP");
     83         decode(false);
     84         PlatformInstrumentation::didDecodeImage();
     85     }
     86     return buffer;
     87 }
     88 
     89 bool BMPImageDecoder::setFailed()
     90 {
     91     m_reader.clear();
     92     return ImageDecoder::setFailed();
     93 }
     94 
     95 void BMPImageDecoder::decode(bool onlySize)
     96 {
     97     if (failed())
     98         return;
     99 
    100     // If we couldn't decode the image but we've received all the data, decoding
    101     // has failed.
    102     if (!decodeHelper(onlySize) && isAllDataReceived())
    103         setFailed();
    104     // If we're done decoding the image, we don't need the BMPImageReader
    105     // anymore.  (If we failed, |m_reader| has already been cleared.)
    106     else if (!m_frameBufferCache.isEmpty() && (m_frameBufferCache.first().status() == ImageFrame::FrameComplete))
    107         m_reader.clear();
    108 }
    109 
    110 bool BMPImageDecoder::decodeHelper(bool onlySize)
    111 {
    112     size_t imgDataOffset = 0;
    113     if ((m_decodedOffset < sizeOfFileHeader) && !processFileHeader(imgDataOffset))
    114         return false;
    115 
    116     if (!m_reader) {
    117         m_reader = adoptPtr(new BMPImageReader(this, m_decodedOffset, imgDataOffset, false));
    118         m_reader->setData(m_data.get());
    119     }
    120 
    121     if (!m_frameBufferCache.isEmpty())
    122         m_reader->setBuffer(&m_frameBufferCache.first());
    123 
    124     return m_reader->decodeBMP(onlySize);
    125 }
    126 
    127 bool BMPImageDecoder::processFileHeader(size_t& imgDataOffset)
    128 {
    129     // Read file header.
    130     ASSERT(!m_decodedOffset);
    131     if (m_data->size() < sizeOfFileHeader)
    132         return false;
    133     const uint16_t fileType = (m_data->data()[0] << 8) | static_cast<uint8_t>(m_data->data()[1]);
    134     imgDataOffset = readUint32(10);
    135     m_decodedOffset = sizeOfFileHeader;
    136 
    137     // See if this is a bitmap filetype we understand.
    138     enum {
    139         BMAP = 0x424D,  // "BM"
    140         // The following additional OS/2 2.x header values (see
    141         // http://www.fileformat.info/format/os2bmp/egff.htm ) aren't widely
    142         // decoded, and are unlikely to be in much use.
    143         /*
    144         ICON = 0x4943,  // "IC"
    145         POINTER = 0x5054,  // "PT"
    146         COLORICON = 0x4349,  // "CI"
    147         COLORPOINTER = 0x4350,  // "CP"
    148         BITMAPARRAY = 0x4241,  // "BA"
    149         */
    150     };
    151     return (fileType == BMAP) || setFailed();
    152 }
    153 
    154 } // namespace blink
    155