/*
* 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 "platform/image-decoders/ImageDecoder.h"
#include "wtf/Noncopyable.h"
#include "wtf/OwnPtr.h"
class GIFImageReader;
typedef Vector<unsigned char> GIFRow;
namespace WebCore {
// This class decodes the GIF image format.
class PLATFORM_EXPORT GIFImageDecoder : public ImageDecoder {
WTF_MAKE_NONCOPYABLE(GIFImageDecoder);
public:
GIFImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption, size_t maxDecodedBytes);
virtual ~GIFImageDecoder();
enum GIFParseQuery { GIFSizeQuery, GIFFrameCountQuery };
// ImageDecoder
virtual String filenameExtension() const OVERRIDE { return "gif"; }
virtual void setData(SharedBuffer* data, bool allDataReceived) OVERRIDE;
virtual bool isSizeAvailable() OVERRIDE;
virtual size_t frameCount() OVERRIDE;
virtual int repetitionCount() const OVERRIDE;
virtual ImageFrame* frameBufferAtIndex(size_t) OVERRIDE;
virtual bool frameIsCompleteAtIndex(size_t) const OVERRIDE;
virtual float frameDurationAtIndex(size_t) const OVERRIDE;
virtual size_t clearCacheExceptFrame(size_t) OVERRIDE;
// CAUTION: setFailed() deletes |m_reader|. Be careful to avoid
// accessing deleted memory, especially when calling this from inside
// GIFImageReader!
virtual bool setFailed() OVERRIDE;
// Callbacks from the GIF reader.
bool haveDecodedRow(size_t frameIndex, GIFRow::const_iterator rowBegin, size_t width, size_t rowNumber, unsigned repeatCount, bool writeTransparentPixels);
bool frameComplete(size_t frameIndex);
// For testing.
bool parseCompleted() const;
private:
virtual void clearFrameBuffer(size_t frameIndex) OVERRIDE;
// Parses as much as is needed to answer the query, ignoring bitmap
// data. If parsing fails, sets the "decode failure" flag.
void parse(GIFParseQuery);
// Decodes bitmap data of the frame. Depending on the disposal method
// of prior frames, also decodes all required prior frames. If decoding
// fails, sets the "decode failure" flag.
void decode(size_t frameIndex);
// 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(size_t frameIndex);
bool m_currentBufferSawAlpha;
mutable int m_repetitionCount;
OwnPtr<GIFImageReader> m_reader;
};
} // namespace WebCore
#endif