/* * Copyright (C) 2006 Apple Computer, Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef GIFImageDecoder_h #define GIFImageDecoder_h #include "ImageDecoder.h" #include <wtf/OwnPtr.h> struct GIFImageReader; namespace WebCore { // This class decodes the GIF image format. class GIFImageDecoder : public ImageDecoder { public: GIFImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption); virtual ~GIFImageDecoder(); enum GIFQuery { GIFFullQuery, GIFSizeQuery, GIFFrameCountQuery }; // ImageDecoder virtual String filenameExtension() const { return "gif"; } virtual void setData(SharedBuffer* data, bool allDataReceived); virtual bool isSizeAvailable(); virtual bool setSize(unsigned width, unsigned height); virtual size_t frameCount(); virtual int repetitionCount() const; virtual ImageFrame* frameBufferAtIndex(size_t index); // CAUTION: setFailed() deletes |m_reader|. Be careful to avoid // accessing deleted memory, especially when calling this from inside // GIFImageReader! virtual bool setFailed(); virtual void clearFrameBufferCache(size_t clearBeforeFrame); // Callbacks from the GIF reader. void decodingHalted(unsigned bytesLeft); bool haveDecodedRow(unsigned frameIndex, unsigned char* rowBuffer, unsigned char* rowEnd, unsigned rowNumber, unsigned repeatCount, bool writeTransparentPixels); bool frameComplete(unsigned frameIndex, unsigned frameDuration, ImageFrame::FrameDisposalMethod disposalMethod); void gifComplete(); private: // If the query is GIFFullQuery, decodes the image up to (but not // including) |haltAtFrame|. Otherwise, decodes as much as is needed to // answer the query, ignoring bitmap data. If decoding fails but there // is no more data coming, sets the "decode failure" flag. void decode(unsigned haltAtFrame, GIFQuery); // Called to initialize the frame buffer with the given index, based on // the previous frame's disposal method. Returns true on success. On // failure, this will mark the image as failed. bool initFrameBuffer(unsigned frameIndex); bool m_alreadyScannedThisDataForFrameCount; bool m_currentBufferSawAlpha; mutable int m_repetitionCount; OwnPtr<GIFImageReader> m_reader; unsigned m_readOffset; }; } // namespace WebCore #endif