1 /* 2 * Copyright (c) 2008, 2009, Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef ICOImageDecoder_h 32 #define ICOImageDecoder_h 33 34 #include "BMPImageReader.h" 35 36 namespace WebCore { 37 38 class PNGImageDecoder; 39 40 // This class decodes the ICO and CUR image formats. 41 class ICOImageDecoder : public ImageDecoder { 42 public: 43 ICOImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption); 44 virtual ~ICOImageDecoder(); 45 46 // ImageDecoder filenameExtension()47 virtual String filenameExtension() const { return "ico"; } 48 virtual void setData(SharedBuffer*, bool allDataReceived); 49 virtual bool isSizeAvailable(); 50 virtual IntSize size() const; 51 virtual IntSize frameSizeAtIndex(size_t) const; 52 virtual bool setSize(unsigned width, unsigned height); 53 virtual size_t frameCount(); 54 virtual ImageFrame* frameBufferAtIndex(size_t); 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(); 59 60 private: 61 enum ImageType { 62 Unknown, 63 BMP, 64 PNG, 65 }; 66 67 struct IconDirectoryEntry { 68 IntSize m_size; 69 uint16_t m_bitCount; 70 uint32_t m_imageOffset; 71 }; 72 73 // Returns true if |a| is a preferable icon entry to |b|. 74 // Larger sizes, or greater bitdepths at the same size, are preferable. 75 static bool compareEntries(const IconDirectoryEntry& a, const IconDirectoryEntry& b); 76 readUint16(int offset)77 inline uint16_t readUint16(int offset) const 78 { 79 return BMPImageReader::readUint16(m_data.get(), m_decodedOffset + offset); 80 } 81 readUint32(int offset)82 inline uint32_t readUint32(int offset) const 83 { 84 return BMPImageReader::readUint32(m_data.get(), m_decodedOffset + offset); 85 } 86 87 // If the desired PNGImageDecoder exists, gives it the appropriate data. 88 void setDataForPNGDecoderAtIndex(size_t); 89 90 // Decodes the entry at |index|. If |onlySize| is true, stops decoding 91 // after calculating the image size. If decoding fails but there is no 92 // more data coming, sets the "decode failure" flag. 93 void decode(size_t index, bool onlySize); 94 95 // Decodes the directory and directory entries at the beginning of the 96 // data, and initializes members. Returns true if all decoding 97 // succeeded. Once this returns true, all entries' sizes are known. 98 bool decodeDirectory(); 99 100 // Decodes the specified entry. 101 bool decodeAtIndex(size_t); 102 103 // Processes the ICONDIR at the beginning of the data. Returns true if 104 // the directory could be decoded. 105 bool processDirectory(); 106 107 // Processes the ICONDIRENTRY records after the directory. Keeps the 108 // "best" entry as the one we'll decode. Returns true if the entries 109 // could be decoded. 110 bool processDirectoryEntries(); 111 112 // Reads and returns a directory entry from the current offset into 113 // |data|. 114 IconDirectoryEntry readDirectoryEntry(); 115 116 // Determines whether the desired entry is a BMP or PNG. Returns true 117 // if the type could be determined. 118 ImageType imageTypeAtIndex(size_t); 119 120 // An index into |m_data| representing how much we've already decoded. 121 // Note that this only tracks data _this_ class decodes; once the 122 // BMPImageReader takes over this will not be updated further. 123 size_t m_decodedOffset; 124 125 // The headers for the ICO. 126 typedef Vector<IconDirectoryEntry> IconDirectoryEntries; 127 IconDirectoryEntries m_dirEntries; 128 129 // The image decoders for the various frames. 130 typedef Vector<OwnPtr<BMPImageReader> > BMPReaders; 131 BMPReaders m_bmpReaders; 132 typedef Vector<OwnPtr<PNGImageDecoder> > PNGDecoders; 133 PNGDecoders m_pngDecoders; 134 135 // Valid only while a BMPImageReader is decoding, this holds the size 136 // for the particular entry being decoded. 137 IntSize m_frameSize; 138 }; 139 140 } // namespace WebCore 141 142 #endif 143