| /* |
| * Copyright (C) 2006 Apple 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 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 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. |
| */ |
| |
| #pragma once |
| |
| #include "ScalableImageDecoder.h" |
| #include <wtf/Lock.h> |
| |
| class GIFImageReader; |
| |
| namespace WebCore { |
| |
| // This class decodes the GIF image format. |
| class GIFImageDecoder final : public ScalableImageDecoder { |
| public: |
| static Ref<ScalableImageDecoder> create(AlphaOption alphaOption, GammaAndColorProfileOption gammaAndColorProfileOption) |
| { |
| return adoptRef(*new GIFImageDecoder(alphaOption, gammaAndColorProfileOption)); |
| } |
| |
| virtual ~GIFImageDecoder(); |
| |
| enum GIFQuery { GIFFullQuery, GIFSizeQuery, GIFFrameCountQuery }; |
| |
| // ScalableImageDecoder |
| String filenameExtension() const final { return "gif"_s; } |
| void setData(SharedBuffer& data, bool allDataReceived) final; |
| bool setSize(const IntSize&) final; |
| size_t frameCount() const final; |
| RepetitionCount repetitionCount() const final; |
| ScalableImageDecoderFrame* frameBufferAtIndex(size_t index) final; |
| // CAUTION: setFailed() deletes |m_reader|. Be careful to avoid |
| // accessing deleted memory, especially when calling this from inside |
| // GIFImageReader! |
| bool setFailed() final; |
| void clearFrameBufferCache(size_t clearBeforeFrame) final; |
| |
| // Callbacks from the GIF reader. |
| bool haveDecodedRow(unsigned frameIndex, const Vector<unsigned char>& rowBuffer, size_t width, size_t rowNumber, unsigned repeatCount, bool writeTransparentPixels); |
| bool frameComplete(unsigned frameIndex, unsigned frameDuration, ScalableImageDecoderFrame::DisposalMethod); |
| void gifComplete(); |
| |
| private: |
| GIFImageDecoder(AlphaOption, GammaAndColorProfileOption); |
| void tryDecodeSize(bool allDataReceived) final { decode(0, GIFSizeQuery, allDataReceived); } |
| size_t findFirstRequiredFrameToDecode(size_t); |
| |
| // 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, bool allDataReceived); |
| |
| // 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_currentBufferSawAlpha; |
| mutable RepetitionCount m_repetitionCount { RepetitionCountOnce }; |
| std::unique_ptr<GIFImageReader> m_reader; |
| }; |
| |
| } // namespace WebCore |