1 /* 2 * Copyright (C) 2006 Apple Computer, 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 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #ifndef GIFImageDecoder_h 27 #define GIFImageDecoder_h 28 29 #include "platform/image-decoders/ImageDecoder.h" 30 #include "wtf/Noncopyable.h" 31 #include "wtf/OwnPtr.h" 32 33 class GIFImageReader; 34 35 typedef Vector<unsigned char> GIFRow; 36 37 namespace blink { 38 39 // This class decodes the GIF image format. 40 class PLATFORM_EXPORT GIFImageDecoder : public ImageDecoder { 41 WTF_MAKE_NONCOPYABLE(GIFImageDecoder); 42 public: 43 GIFImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption, size_t maxDecodedBytes); 44 virtual ~GIFImageDecoder(); 45 46 enum GIFParseQuery { GIFSizeQuery, GIFFrameCountQuery }; 47 48 // ImageDecoder 49 virtual String filenameExtension() const OVERRIDE { return "gif"; } 50 virtual void setData(SharedBuffer* data, bool allDataReceived) OVERRIDE; 51 virtual bool isSizeAvailable() OVERRIDE; 52 virtual size_t frameCount() OVERRIDE; 53 virtual int repetitionCount() const OVERRIDE; 54 virtual ImageFrame* frameBufferAtIndex(size_t) OVERRIDE; 55 virtual bool frameIsCompleteAtIndex(size_t) const OVERRIDE; 56 virtual float frameDurationAtIndex(size_t) const OVERRIDE; 57 virtual size_t clearCacheExceptFrame(size_t) OVERRIDE; 58 // CAUTION: setFailed() deletes |m_reader|. Be careful to avoid 59 // accessing deleted memory, especially when calling this from inside 60 // GIFImageReader! 61 virtual bool setFailed() OVERRIDE; 62 63 // Callbacks from the GIF reader. 64 bool haveDecodedRow(size_t frameIndex, GIFRow::const_iterator rowBegin, size_t width, size_t rowNumber, unsigned repeatCount, bool writeTransparentPixels); 65 bool frameComplete(size_t frameIndex); 66 67 // For testing. 68 bool parseCompleted() const; 69 70 private: 71 virtual void clearFrameBuffer(size_t frameIndex) OVERRIDE; 72 73 // Parses as much as is needed to answer the query, ignoring bitmap 74 // data. If parsing fails, sets the "decode failure" flag. 75 void parse(GIFParseQuery); 76 77 // Decodes bitmap data of the frame. Depending on the disposal method 78 // of prior frames, also decodes all required prior frames. If decoding 79 // fails, sets the "decode failure" flag. 80 void decode(size_t frameIndex); 81 82 // Called to initialize the frame buffer with the given index, based on 83 // the previous frame's disposal method. Returns true on success. On 84 // failure, this will mark the image as failed. 85 bool initFrameBuffer(size_t frameIndex); 86 87 bool m_currentBufferSawAlpha; 88 mutable int m_repetitionCount; 89 OwnPtr<GIFImageReader> m_reader; 90 }; 91 92 } // namespace blink 93 94 #endif 95
