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31 #ifndef ICOImageDecoder_h
32 #define ICOImageDecoder_h
34 #include "platform/image-decoders/bmp/BMPImageReader.h"
38 class PNGImageDecoder;
40 // This class decodes the ICO and CUR image formats.
41 class PLATFORM_EXPORT ICOImageDecoder : public ImageDecoder {
43 ICOImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption, size_t maxDecodedBytes);
44 virtual ~ICOImageDecoder();
47 virtual String filenameExtension() const OVERRIDE { return "ico"; }
48 virtual void setData(SharedBuffer*, bool allDataReceived) OVERRIDE;
49 virtual bool isSizeAvailable() OVERRIDE;
50 virtual IntSize size() const OVERRIDE;
51 virtual IntSize frameSizeAtIndex(size_t) const OVERRIDE;
52 virtual bool setSize(unsigned width, unsigned height) OVERRIDE;
53 virtual size_t frameCount() OVERRIDE;
54 virtual ImageFrame* frameBufferAtIndex(size_t) OVERRIDE;
55 // CAUTION: setFailed() deletes all readers and decoders. Be careful to
56 // avoid accessing deleted memory, especially when calling this from
57 // inside BMPImageReader!
58 virtual bool setFailed() OVERRIDE;
59 virtual bool hotSpot(IntPoint&) const OVERRIDE;
73 struct IconDirectoryEntry {
77 uint32_t m_imageOffset;
80 // Returns true if |a| is a preferable icon entry to |b|.
81 // Larger sizes, or greater bitdepths at the same size, are preferable.
82 static bool compareEntries(const IconDirectoryEntry& a, const IconDirectoryEntry& b);
84 inline uint16_t readUint16(int offset) const
86 return BMPImageReader::readUint16(m_data.get(), m_decodedOffset + offset);
89 inline uint32_t readUint32(int offset) const
91 return BMPImageReader::readUint32(m_data.get(), m_decodedOffset + offset);
94 // If the desired PNGImageDecoder exists, gives it the appropriate data.
95 void setDataForPNGDecoderAtIndex(size_t);
97 // Decodes the entry at |index|. If |onlySize| is true, stops decoding
98 // after calculating the image size. If decoding fails but there is no
99 // more data coming, sets the "decode failure" flag.
100 void decode(size_t index, bool onlySize);
102 // Decodes the directory and directory entries at the beginning of the
103 // data, and initializes members. Returns true if all decoding
104 // succeeded. Once this returns true, all entries' sizes are known.
105 bool decodeDirectory();
107 // Decodes the specified entry.
108 bool decodeAtIndex(size_t);
110 // Processes the ICONDIR at the beginning of the data. Returns true if
111 // the directory could be decoded.
112 bool processDirectory();
114 // Processes the ICONDIRENTRY records after the directory. Keeps the
115 // "best" entry as the one we'll decode. Returns true if the entries
117 bool processDirectoryEntries();
119 // Stores the hot-spot for |index| in |hotSpot| and returns true,
120 // or returns false if there is none.
121 bool hotSpotAtIndex(size_t index, IntPoint& hotSpot) const;
123 // Reads and returns a directory entry from the current offset into
125 IconDirectoryEntry readDirectoryEntry();
127 // Determines whether the desired entry is a BMP or PNG. Returns true
128 // if the type could be determined.
129 ImageType imageTypeAtIndex(size_t);
131 // An index into |m_data| representing how much we've already decoded.
132 // Note that this only tracks data _this_ class decodes; once the
133 // BMPImageReader takes over this will not be updated further.
134 size_t m_decodedOffset;
136 // Which type of file (ICO/CUR) this is.
139 // The headers for the ICO.
140 typedef Vector<IconDirectoryEntry> IconDirectoryEntries;
141 IconDirectoryEntries m_dirEntries;
143 // The image decoders for the various frames.
144 typedef Vector<OwnPtr<BMPImageReader> > BMPReaders;
145 BMPReaders m_bmpReaders;
146 typedef Vector<OwnPtr<PNGImageDecoder> > PNGDecoders;
147 PNGDecoders m_pngDecoders;
149 // Valid only while a BMPImageReader is decoding, this holds the size
150 // for the particular entry being decoded.
154 } // namespace WebCore