external/webkit r30707

1 files changed, 87 insertions, 0 deletions

diff --git a/WebCore/platform/image-decoders/gif/GIFImageDecoder.h b/WebCore/platform/image-decoders/gif/GIFImageDecoder.h
new file mode 100644
index 0000000..7d22325
--- /dev/null
+++ b/WebCore/platform/image-decoders/gif/GIFImageDecoder.h
@@ -0,0 +1,87 @@
+/*
+ * 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 GIF_DECODER_H_
+#define GIF_DECODER_H_
+
+#include "ImageDecoder.h"
+
+namespace WebCore {
+
+class GIFImageDecoderPrivate;
+
+// This class decodes the GIF image format.
+class GIFImageDecoder : public ImageDecoder
+{
+public:
+    GIFImageDecoder();
+    ~GIFImageDecoder();
+
+    // Take the data and store it.
+    virtual void setData(SharedBuffer* data, bool allDataReceived);
+
+    // Whether or not the size information has been decoded yet.
+    virtual bool isSizeAvailable() const;
+
+    // The total number of frames for the image.  Will scan the image data for the answer
+    // (without necessarily decoding all of the individual frames).
+    virtual int frameCount();
+
+    // The number of repetitions to perform for an animation loop.
+    virtual int repetitionCount() const;
+
+    virtual RGBA32Buffer* frameBufferAtIndex(size_t index);
+
+    virtual unsigned frameDurationAtIndex(size_t index) { return 0; }
+
+    enum GIFQuery { GIFFullQuery, GIFSizeQuery, GIFFrameCountQuery };
+
+    void decode(GIFQuery query, unsigned haltAtFrame) const;
+
+    // Callbacks from the GIF reader.
+    void sizeNowAvailable(unsigned width, unsigned height);
+    void decodingHalted(unsigned bytesLeft);
+    void haveDecodedRow(unsigned frameIndex, unsigned char* rowBuffer, unsigned char* rowEnd, unsigned rowNumber, 
+                        unsigned repeatCount, bool writeTransparentPixels);
+    void frameComplete(unsigned frameIndex, unsigned frameDuration, RGBA32Buffer::FrameDisposalMethod disposalMethod);
+    void gifComplete();
+
+private:
+    // Called to initialize the frame buffer with the given index, based on the
+    // previous frame's disposal method.
+    void initFrameBuffer(unsigned frameIndex);
+
+    // A helper for initFrameBuffer(), this sets the size of the buffer, and
+    // fills it with transparent pixels.
+    void prepEmptyFrameBuffer(RGBA32Buffer* buffer) const;
+
+    bool m_frameCountValid;
+    bool m_currentBufferSawAlpha;
+    mutable GIFImageDecoderPrivate* m_reader;
+};
+
+}
+
+#endif