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 "ImageDecoder.h" 30 #include <wtf/OwnPtr.h> 31 32 class GIFImageReader; 33 34 namespace WebCore { 35 36 // This class decodes the GIF image format. 37 class GIFImageDecoder : public ImageDecoder { 38 public: 39 GIFImageDecoder(); 40 ~GIFImageDecoder(); 41 42 virtual String filenameExtension() const { return "gif"; } 43 44 // Take the data and store it. 45 virtual void setData(SharedBuffer* data, bool allDataReceived); 46 47 // Whether or not the size information has been decoded yet. 48 virtual bool isSizeAvailable(); 49 50 // The total number of frames for the image. Will scan the image data for the answer 51 // (without necessarily decoding all of the individual frames). 52 virtual size_t frameCount(); 53 54 // The number of repetitions to perform for an animation loop. 55 virtual int repetitionCount() const; 56 57 virtual RGBA32Buffer* frameBufferAtIndex(size_t index); 58 59 virtual void clearFrameBufferCache(size_t clearBeforeFrame); 60 61 virtual unsigned frameDurationAtIndex(size_t index) { return 0; } 62 63 enum GIFQuery { GIFFullQuery, GIFSizeQuery, GIFFrameCountQuery }; 64 65 void decode(GIFQuery, unsigned haltAtFrame); 66 67 // Callbacks from the GIF reader. 68 bool sizeNowAvailable(unsigned width, unsigned height); 69 void decodingHalted(unsigned bytesLeft); 70 bool haveDecodedRow(unsigned frameIndex, unsigned char* rowBuffer, unsigned char* rowEnd, unsigned rowNumber, 71 unsigned repeatCount, bool writeTransparentPixels); 72 void frameComplete(unsigned frameIndex, unsigned frameDuration, RGBA32Buffer::FrameDisposalMethod disposalMethod); 73 void gifComplete(); 74 75 private: 76 // Called to initialize the frame buffer with the given index, based on the 77 // previous frame's disposal method. Returns true on success. On failure, 78 // this will mark the image as failed. 79 bool initFrameBuffer(unsigned frameIndex); 80 81 bool m_frameCountValid; 82 bool m_currentBufferSawAlpha; 83 mutable int m_repetitionCount; 84 OwnPtr<GIFImageReader> m_reader; 85 unsigned m_readOffset; 86 }; 87 88 } // namespace WebCore 89 90 #endif 91
