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*
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* notice, this list of conditions and the following disclaimer.
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* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
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* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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*/
#include "config.h"
#include "platform/image-decoders/bmp/BMPImageDecoder.h"
#include "platform/PlatformInstrumentation.h"
#include "wtf/PassOwnPtr.h"
namespace WebCore {
// Number of bits in .BMP used to store the file header (doesn't match
// "sizeof(BMPImageDecoder::BitmapFileHeader)" since we omit some fields and
// don't pack).
static const size_t sizeOfFileHeader = 14;
BMPImageDecoder::BMPImageDecoder(ImageSource::AlphaOption alphaOption,
ImageSource::GammaAndColorProfileOption gammaAndColorProfileOption,
size_t maxDecodedBytes)
: ImageDecoder(alphaOption, gammaAndColorProfileOption, maxDecodedBytes)
, m_decodedOffset(0)
{
}
void BMPImageDecoder::setData(SharedBuffer* data, bool allDataReceived)
{
if (failed())
return;
ImageDecoder::setData(data, allDataReceived);
if (m_reader)
m_reader->setData(data);
}
bool BMPImageDecoder::isSizeAvailable()
{
if (!ImageDecoder::isSizeAvailable())
decode(true);
return ImageDecoder::isSizeAvailable();
}
ImageFrame* BMPImageDecoder::frameBufferAtIndex(size_t index)
{
if (index)
return 0;
if (m_frameBufferCache.isEmpty()) {
m_frameBufferCache.resize(1);
m_frameBufferCache.first().setPremultiplyAlpha(m_premultiplyAlpha);
}
ImageFrame* buffer = &m_frameBufferCache.first();
if (buffer->status() != ImageFrame::FrameComplete) {
PlatformInstrumentation::willDecodeImage("BMP");
decode(false);
PlatformInstrumentation::didDecodeImage();
}
return buffer;
}
bool BMPImageDecoder::setFailed()
{
m_reader.clear();
return ImageDecoder::setFailed();
}
void BMPImageDecoder::decode(bool onlySize)
{
if (failed())
return;
// If we couldn't decode the image but we've received all the data, decoding
// has failed.
if (!decodeHelper(onlySize) && isAllDataReceived())
setFailed();
// If we're done decoding the image, we don't need the BMPImageReader
// anymore. (If we failed, |m_reader| has already been cleared.)
else if (!m_frameBufferCache.isEmpty() && (m_frameBufferCache.first().status() == ImageFrame::FrameComplete))
m_reader.clear();
}
bool BMPImageDecoder::decodeHelper(bool onlySize)
{
size_t imgDataOffset = 0;
if ((m_decodedOffset < sizeOfFileHeader) && !processFileHeader(&imgDataOffset))
return false;
if (!m_reader) {
m_reader = adoptPtr(new BMPImageReader(this, m_decodedOffset, imgDataOffset, false));
m_reader->setData(m_data.get());
}
if (!m_frameBufferCache.isEmpty())
m_reader->setBuffer(&m_frameBufferCache.first());
return m_reader->decodeBMP(onlySize);
}
bool BMPImageDecoder::processFileHeader(size_t* imgDataOffset)
{
ASSERT(imgDataOffset);
// Read file header.
ASSERT(!m_decodedOffset);
if (m_data->size() < sizeOfFileHeader)
return false;
const uint16_t fileType = (m_data->data()[0] << 8) | static_cast<uint8_t>(m_data->data()[1]);
*imgDataOffset = readUint32(10);
m_decodedOffset = sizeOfFileHeader;
// See if this is a bitmap filetype we understand.
enum {
BMAP = 0x424D, // "BM"
// The following additional OS/2 2.x header values (see
// http://www.fileformat.info/format/os2bmp/egff.htm ) aren't widely
// decoded, and are unlikely to be in much use.
/*
ICON = 0x4943, // "IC"
POINTER = 0x5054, // "PT"
COLORICON = 0x4349, // "CI"
COLORPOINTER = 0x4350, // "CP"
BITMAPARRAY = 0x4241, // "BA"
*/
};
return (fileType == BMAP) || setFailed();
}
} // namespace WebCore