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#ifndef ICOImageDecoder_h
#define ICOImageDecoder_h
#include "platform/image-decoders/bmp/BMPImageReader.h"
namespace WebCore {
class PNGImageDecoder;
// This class decodes the ICO and CUR image formats.
class PLATFORM_EXPORT ICOImageDecoder : public ImageDecoder {
public:
ICOImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption, size_t maxDecodedBytes);
virtual ~ICOImageDecoder();
// ImageDecoder
virtual String filenameExtension() const OVERRIDE { return "ico"; }
virtual void setData(SharedBuffer*, bool allDataReceived) OVERRIDE;
virtual bool isSizeAvailable() OVERRIDE;
virtual IntSize size() const OVERRIDE;
virtual IntSize frameSizeAtIndex(size_t) const OVERRIDE;
virtual bool setSize(unsigned width, unsigned height) OVERRIDE;
virtual size_t frameCount() OVERRIDE;
virtual ImageFrame* frameBufferAtIndex(size_t) OVERRIDE;
// CAUTION: setFailed() deletes all readers and decoders. Be careful to
// avoid accessing deleted memory, especially when calling this from
// inside BMPImageReader!
virtual bool setFailed() OVERRIDE;
virtual bool hotSpot(IntPoint&) const OVERRIDE;
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;
};
// 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();
// Stores the hot-spot for |index| in |hotSpot| and returns true,
// or returns false if there is none.
bool hotSpotAtIndex(size_t index, IntPoint& hotSpot) 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<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