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/*
 * Copyright (c) 2008, 2009, Google 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:
 * 
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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 THE COPYRIGHT
 * OWNER 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 BMPImageDecoder_h
#define BMPImageDecoder_h

#include "BMPImageReader.h"
#include <wtf/OwnPtr.h>

namespace WebCore {

    // This class decodes the BMP image format.
    class BMPImageDecoder : public ImageDecoder {
    public:
        BMPImageDecoder(bool premultiplyAlpha, bool ignoreGammaAndColorProfile);

        // ImageDecoder
        virtual String filenameExtension() const { return "bmp"; }
        virtual void setData(SharedBuffer*, bool allDataReceived);
        virtual bool isSizeAvailable();
        virtual RGBA32Buffer* frameBufferAtIndex(size_t index);
        // CAUTION: setFailed() deletes |m_reader|.  Be careful to avoid
        // accessing deleted memory, especially when calling this from inside
        // BMPImageReader!
        virtual bool setFailed();

    private:
        inline uint32_t readUint32(int offset) const
        {
            return BMPImageReader::readUint32(m_data.get(), m_decodedOffset + offset);
        }

        // Decodes the image.  If |onlySize| is true, stops decoding after
        // calculating the image size.  If decoding fails but there is no more
        // data coming, sets the "decode failure" flag.
        void decode(bool onlySize);

        // Decodes the image.  If |onlySize| is true, stops decoding after
        // calculating the image size.  Returns whether decoding succeeded.
        bool decodeHelper(bool onlySize);

        // Processes the file header at the beginning of the data.  Sets
        // |*imgDataOffset| based on the header contents.  Returns true if the
        // file header could be decoded.
        bool processFileHeader(size_t* imgDataOffset);

        // An index into |m_data| representing how much we've already decoded.
        // Note that this only tracks data _this_ class decodes; once the
        // BMPImageReader takes over this will not be updated further.
        size_t m_decodedOffset;

        // The reader used to do most of the BMP decoding.
        OwnPtr<BMPImageReader> m_reader;
    };

} // namespace WebCore

#endif