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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.
*/
#pragma once
#include "BMPImageReader.h"
namespace WebCore {
// This class decodes the ICO and CUR image formats.
class ICOImageDecoder final : public ScalableImageDecoder {
public:
static Ref<ScalableImageDecoder> create(AlphaOption alphaOption, GammaAndColorProfileOption gammaAndColorProfileOption)
{
return adoptRef(*new ICOImageDecoder(alphaOption, gammaAndColorProfileOption));
}
virtual ~ICOImageDecoder();
// ScalableImageDecoder
String filenameExtension() const final { return "ico"_s; }
void setData(const FragmentedSharedBuffer&, bool allDataReceived) final;
IntSize size() const final;
IntSize frameSizeAtIndex(size_t, SubsamplingLevel) const final;
bool setSize(const IntSize&) final;
size_t frameCount() const final;
ScalableImageDecoderFrame* frameBufferAtIndex(size_t) final;
// CAUTION: setFailed() deletes all readers and decoders. Be careful to
// avoid accessing deleted memory, especially when calling this from
// inside BMPImageReader!
bool setFailed() final;
std::optional<IntPoint> hotSpot() const final;
private:
enum ImageType {
Unknown,
BMP,
PNG,
};
enum FileType {
ICON = 1,
CURSOR = 2,
};
struct IconDirectoryEntry {
IntSize m_size;
uint16_t m_bitCount;
IntPoint m_hotSpot;
uint32_t m_imageOffset;
};
ICOImageDecoder(AlphaOption, GammaAndColorProfileOption);
void tryDecodeSize(bool allDataReceived) final { decode(0, true, allDataReceived); }
// 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, m_decodedOffset + offset);
}
inline uint32_t readUint32(int offset) const
{
return BMPImageReader::readUint32(*m_data, 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, bool allDataReceived);
// 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();
// Returns the hot-spot for |index|, returns std::nullopt if there is none.
std::optional<IntPoint> hotSpotAtIndex(size_t) const;
// 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;
// Which type of file (ICO/CUR) this is.
FileType m_fileType;
// The headers for the ICO.
typedef Vector<IconDirectoryEntry> IconDirectoryEntries;
IconDirectoryEntries m_dirEntries;
// The image decoders for the various frames.
typedef Vector<std::unique_ptr<BMPImageReader>> BMPReaders;
BMPReaders m_bmpReaders;
typedef Vector<RefPtr<ScalableImageDecoder>> 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
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