[WIP] Move ImageDecoders to SkCodec

third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.h

-/*
- * 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 <memory>
-#include "platform/image-decoders/ImageDecoder.h"
-#include "platform/wtf/Noncopyable.h"
-
-namespace blink {
-
-class GIFImageReader;
-
-using GIFRow = Vector<unsigned char>;
-
-// This class decodes the GIF image format.
-class PLATFORM_EXPORT GIFImageDecoder final : public ImageDecoder {
-  WTF_MAKE_NONCOPYABLE(GIFImageDecoder);
-
- public:
-  GIFImageDecoder(AlphaOption, const ColorBehavior&, size_t max_decoded_bytes);
-  ~GIFImageDecoder() override;
-
-  enum GIFParseQuery { kGIFSizeQuery, kGIFFrameCountQuery };
-
-  // ImageDecoder:
-  String FilenameExtension() const override { return "gif"; }
-  void OnSetData(SegmentReader* data) override;
-  int RepetitionCount() const override;
-  bool FrameIsCompleteAtIndex(size_t) const override;
-  float FrameDurationAtIndex(size_t) const override;
-  // CAUTION: SetFailed() deletes |reader_|.  Be careful to avoid
-  // accessing deleted memory, especially when calling this from inside
-  // GIFImageReader!
-  bool SetFailed() override;
-
-  // Callbacks from the GIF reader.
-  bool HaveDecodedRow(size_t frame_index,
-                      GIFRow::const_iterator row_begin,
-                      size_t width,
-                      size_t row_number,
-                      unsigned repeat_count,
-                      bool write_transparent_pixels);
-  bool FrameComplete(size_t frame_index);
-
-  // For testing.
-  bool ParseCompleted() const;
-
- private:
-  // ImageDecoder:
-  void ClearFrameBuffer(size_t frame_index) override;
-  virtual void DecodeSize() { Parse(kGIFSizeQuery); }
-  size_t DecodeFrameCount() override;
-  void InitializeNewFrame(size_t) override;
-  void Decode(size_t) 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);
-
-  // Reset the alpha tracker for this frame. Before calling this method, the
-  // caller must verify that the frame exists.
-  void OnInitFrameBuffer(size_t) override;
-
-  // When the disposal method of the frame is DisposeOverWritePrevious, the
-  // next frame will use the previous frame's buffer as its starting state, so
-  // we can't take over the data in that case. Before calling this method, the
-  // caller must verify that the frame exists.
-  bool CanReusePreviousFrameBuffer(size_t) const override;
-
-  bool current_buffer_saw_alpha_;
-  mutable int repetition_count_;
-  std::unique_ptr<GIFImageReader> reader_;
-};
-
-}  // namespace blink
-
-#endif