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 THIRD_PARTY_BLINK_RENDERER_PLATFORM_IMAGE_DECODERS_ICO_ICO_IMAGE_DECODER_H_ 32 #define THIRD_PARTY_BLINK_RENDERER_PLATFORM_IMAGE_DECODERS_ICO_ICO_IMAGE_DECODER_H_ 33 34 #include <memory> 35 36 #include "third_party/blink/renderer/platform/image-decoders/bmp/bmp_image_reader.h" 37 #include "third_party/blink/renderer/platform/image-decoders/fast_shared_buffer_reader.h" 38 39 namespace blink { 40 41 class PNGImageDecoder; 42 43 // This class decodes the ICO and CUR image formats. 44 class PLATFORM_EXPORT ICOImageDecoder final : public ImageDecoder { 45 public: 46 ICOImageDecoder(AlphaOption, const ColorBehavior&, size_t max_decoded_bytes); 47 ~ICOImageDecoder() override; 48 49 // ImageDecoder: FilenameExtension()50 String FilenameExtension() const override { return "ico"; } 51 void OnSetData(SegmentReader*) override; 52 IntSize Size() const override; 53 IntSize FrameSizeAtIndex(size_t) const override; 54 bool SetSize(unsigned width, unsigned height) override; 55 bool FrameIsReceivedAtIndex(size_t) const override; 56 // CAUTION: SetFailed() deletes all readers and decoders. Be careful to 57 // avoid accessing deleted memory, especially when calling this from 58 // inside BMPImageReader! 59 bool SetFailed() override; 60 bool HotSpot(IntPoint&) const override; 61 62 private: 63 enum ImageType { 64 kUnknown, 65 BMP, 66 PNG, 67 }; 68 69 enum FileType { 70 ICON = 1, 71 CURSOR = 2, 72 }; 73 74 struct IconDirectoryEntry { 75 DISALLOW_NEW(); 76 IntSize size_; 77 uint16_t bit_count_; 78 IntPoint hot_spot_; 79 uint32_t image_offset_; 80 uint32_t byte_size_; 81 }; 82 83 // Returns true if |a| is a preferable icon entry to |b|. 84 // Larger sizes, or greater bitdepths at the same size, are preferable. 85 static bool CompareEntries(const IconDirectoryEntry& a, 86 const IconDirectoryEntry& b); 87 88 // ImageDecoder: DecodeSize()89 void DecodeSize() override { Decode(0, true); } 90 size_t DecodeFrameCount() override; Decode(size_t index)91 void Decode(size_t index) override { Decode(index, false); } 92 93 // TODO (scroggo): These functions are identical to functions in 94 // BMPImageReader. Share code? ReadUint8(size_t offset)95 inline uint8_t ReadUint8(size_t offset) const { 96 return fast_reader_.GetOneByte(decoded_offset_ + offset); 97 } 98 ReadUint16(int offset)99 inline uint16_t ReadUint16(int offset) const { 100 char buffer[2]; 101 const char* data = 102 fast_reader_.GetConsecutiveData(decoded_offset_ + offset, 2, buffer); 103 return BMPImageReader::ReadUint16(data); 104 } 105 ReadUint32(int offset)106 inline uint32_t ReadUint32(int offset) const { 107 char buffer[4]; 108 const char* data = 109 fast_reader_.GetConsecutiveData(decoded_offset_ + offset, 4, buffer); 110 return BMPImageReader::ReadUint32(data); 111 } 112 113 // If the desired PNGImageDecoder exists, gives it the appropriate data. 114 void SetDataForPNGDecoderAtIndex(size_t); 115 116 // Decodes the entry at |index|. If |only_size| is true, stops decoding 117 // after calculating the image size. If decoding fails but there is no 118 // more data coming, sets the "decode failure" flag. 119 void Decode(size_t index, bool only_size); 120 121 // Decodes the directory and directory entries at the beginning of the 122 // data, and initializes members. Returns true if all decoding 123 // succeeded. Once this returns true, all entries' sizes are known. 124 bool DecodeDirectory(); 125 126 // Decodes the specified entry. 127 bool DecodeAtIndex(size_t); 128 129 // Processes the ICONDIR at the beginning of the data. Returns true if 130 // the directory could be decoded. 131 bool ProcessDirectory(); 132 133 // Processes the ICONDIRENTRY records after the directory. Keeps the 134 // "best" entry as the one we'll decode. Returns true if the entries 135 // could be decoded. 136 bool ProcessDirectoryEntries(); 137 138 // Stores the hot-spot for |index| in |hot_spot| and returns true, 139 // or returns false if there is none. 140 bool HotSpotAtIndex(size_t index, IntPoint& hot_spot) const; 141 142 // Reads and returns a directory entry from the current offset into 143 // |data|. 144 IconDirectoryEntry ReadDirectoryEntry(); 145 146 // Determines whether the desired entry is a BMP or PNG. Returns true 147 // if the type could be determined. 148 ImageType ImageTypeAtIndex(size_t); 149 150 FastSharedBufferReader fast_reader_{nullptr}; 151 152 // An index into |data_| representing how much we've already decoded. 153 // Note that this only tracks data _this_ class decodes; once the 154 // BMPImageReader takes over this will not be updated further. 155 size_t decoded_offset_ = 0; 156 157 // Which type of file (ICO/CUR) this is. 158 FileType file_type_; 159 160 // The headers for the ICO. 161 typedef Vector<IconDirectoryEntry> IconDirectoryEntries; 162 IconDirectoryEntries dir_entries_; 163 164 // Count of directory entries is parsed from header before initializing 165 // dir_entries_. dir_entries_ is populated only when full header 166 // information including directory entries is available. 167 size_t dir_entries_count_ = 0; 168 169 // The image decoders for the various frames. 170 typedef Vector<std::unique_ptr<BMPImageReader>> BMPReaders; 171 BMPReaders bmp_readers_; 172 typedef Vector<std::unique_ptr<PNGImageDecoder>> PNGDecoders; 173 PNGDecoders png_decoders_; 174 175 // Valid only while a BMPImageReader is decoding, this holds the size 176 // for the particular entry being decoded. 177 IntSize frame_size_; 178 179 DISALLOW_COPY_AND_ASSIGN(ICOImageDecoder); 180 }; 181 182 } // namespace blink 183 184 #endif 185