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/*
* Copyright (c) 2008, 2009, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* 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
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef ICOImageDecoder_h
#define ICOImageDecoder_h
#include "BMPImageReader.h"
namespace WebCore {
class PNGImageDecoder;
// This class decodes the ICO and CUR image formats.
class ICOImageDecoder : public ImageDecoder {
public:
ICOImageDecoder(bool premultiplyAlpha, bool ignoreGammaAndColorProfile);
virtual ~ICOImageDecoder();
// ImageDecoder
virtual String filenameExtension() const { return "ico"; }
virtual void setData(SharedBuffer*, bool allDataReceived);
virtual bool isSizeAvailable();
virtual IntSize size() const;
virtual IntSize frameSizeAtIndex(size_t) const;
virtual bool setSize(unsigned width, unsigned height);
virtual size_t frameCount();
virtual RGBA32Buffer* frameBufferAtIndex(size_t);
// CAUTION: setFailed() deletes all readers and decoders. Be careful to
// avoid accessing deleted memory, especially when calling this from
// inside BMPImageReader!
virtual bool setFailed();
private:
enum ImageType {
Unknown,
BMP,
PNG,
};
struct IconDirectoryEntry {
IntSize m_size;
uint16_t m_bitCount;
uint32_t m_imageOffset;
};
// Returns true if |a| is a preferable icon entry to |b|.
// Larger sizes, or greater bitdepths at the same size, are preferable.
static bool compareEntries(const IconDirectoryEntry& a, const IconDirectoryEntry& b);
inline uint16_t readUint16(int offset) const
{
return BMPImageReader::readUint16(m_data.get(), m_decodedOffset + offset);
}
inline uint32_t readUint32(int offset) const
{
return BMPImageReader::readUint32(m_data.get(), m_decodedOffset + offset);
}
// If the desired PNGImageDecoder exists, gives it the appropriate data.
void setDataForPNGDecoderAtIndex(size_t);
// Decodes the entry at |index|. If |onlySize| is true, stops decoding
// after calculating the image size. If decoding fails but there is no
// more data coming, sets the "decode failure" flag.
void decode(size_t index, bool onlySize);
// Decodes the directory and directory entries at the beginning of the
// data, and initializes members. Returns true if all decoding
// succeeded. Once this returns true, all entries' sizes are known.
bool decodeDirectory();
// Decodes the specified entry.
bool decodeAtIndex(size_t);
// Processes the ICONDIR at the beginning of the data. Returns true if
// the directory could be decoded.
bool processDirectory();
// Processes the ICONDIRENTRY records after the directory. Keeps the
// "best" entry as the one we'll decode. Returns true if the entries
// could be decoded.
bool processDirectoryEntries();
// Reads and returns a directory entry from the current offset into
// |data|.
IconDirectoryEntry readDirectoryEntry();
// Determines whether the desired entry is a BMP or PNG. Returns true
// if the type could be determined.
ImageType imageTypeAtIndex(size_t);
// An index into |m_data| representing how much we've already decoded.
// Note that this only tracks data _this_ class decodes; once the
// BMPImageReader takes over this will not be updated further.
size_t m_decodedOffset;
// The headers for the ICO.
typedef Vector<IconDirectoryEntry> IconDirectoryEntries;
IconDirectoryEntries m_dirEntries;
// The image decoders for the various frames.
typedef Vector<OwnPtr<BMPImageReader> > BMPReaders;
BMPReaders m_bmpReaders;
typedef Vector<OwnPtr<PNGImageDecoder> > PNGDecoders;
PNGDecoders m_pngDecoders;
// Valid only while a BMPImageReader is decoding, this holds the size
// for the particular entry being decoded.
IntSize m_frameSize;
};
} // namespace WebCore
#endif
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