Moving GraphicsContext and dependencies from core to platform.

Source/platform/image-decoders/bmp/BMPImageDecoder.h

+/*
+ * 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 "platform/image-decoders/bmp/BMPImageReader.h"
+#include "wtf/OwnPtr.h"
+
+namespace WebCore {
+
+// This class decodes the BMP image format.
+class PLATFORM_EXPORT BMPImageDecoder : public ImageDecoder {
+public:
+    BMPImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption, size_t maxDecodedBytes);
+
+    // ImageDecoder
+    virtual String filenameExtension() const { return "bmp"; }
+    virtual void setData(SharedBuffer*, bool allDataReceived);
+    virtual bool isSizeAvailable();
+    virtual ImageFrame* frameBufferAtIndex(size_t);
+    // 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