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 "platform/image-decoders/bmp/BMPImageReader.h" 35 36 namespace blink { 37 38 class PNGImageDecoder; 39 40 // This class decodes the ICO and CUR image formats. 41 class PLATFORM_EXPORT ICOImageDecoder : public ImageDecoder { 42 public: 43 ICOImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption, size_t maxDecodedBytes); 44 virtual ~ICOImageDecoder(); 45 46 // ImageDecoder filenameExtension()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; 60 61 private: 62 enum ImageType { 63 Unknown, 64 BMP, 65 PNG, 66 }; 67 68 enum FileType { 69 ICON = 1, 70 CURSOR = 2, 71 }; 72 73 struct IconDirectoryEntry { 74 IntSize m_size; 75 uint16_t m_bitCount; 76 IntPoint m_hotSpot; 77 uint32_t m_imageOffset; 78 }; 79 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); 83 readUint16(int offset)84 inline uint16_t readUint16(int offset) const 85 { 86 return BMPImageReader::readUint16(m_data.get(), m_decodedOffset + offset); 87 } 88 readUint32(int offset)89 inline uint32_t readUint32(int offset) const 90 { 91 return BMPImageReader::readUint32(m_data.get(), m_decodedOffset + offset); 92 } 93 94 // If the desired PNGImageDecoder exists, gives it the appropriate data. 95 void setDataForPNGDecoderAtIndex(size_t); 96 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); 101 102 // 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(); 106 107 // Decodes the specified entry. 108 bool decodeAtIndex(size_t); 109 110 // Processes the ICONDIR at the beginning of the data. Returns true if 111 // the directory could be decoded. 112 bool processDirectory(); 113 114 // Processes the ICONDIRENTRY records after the directory. Keeps the 115 // "best" entry as the one we'll decode. Returns true if the entries 116 // could be decoded. 117 bool processDirectoryEntries(); 118 119 // 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; 122 123 // Reads and returns a directory entry from the current offset into 124 // |data|. 125 IconDirectoryEntry readDirectoryEntry(); 126 127 // Determines whether the desired entry is a BMP or PNG. Returns true 128 // if the type could be determined. 129 ImageType imageTypeAtIndex(size_t); 130 131 // 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; 135 136 // Which type of file (ICO/CUR) this is. 137 FileType m_fileType; 138 139 // The headers for the ICO. 140 typedef Vector<IconDirectoryEntry> IconDirectoryEntries; 141 IconDirectoryEntries m_dirEntries; 142 143 // 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; 148 149 // Valid only while a BMPImageReader is decoding, this holds the size 150 // for the particular entry being decoded. 151 IntSize m_frameSize; 152 }; 153 154 } // namespace blink 155 156 #endif 157