Animated PNG implementation

third_party/WebKit/Source/platform/image-decoders/png/PNGImageDecoder.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
@@ skipping 27 matching lines @@
 
  public:
   PNGImageDecoder(AlphaOption,
                   ColorSpaceOption,
                   size_t maxDecodedBytes,
                   size_t offset = 0);
   ~PNGImageDecoder() override;
 
   // ImageDecoder:
   String filenameExtension() const override { return "png"; }
+  bool frameIsCompleteAtIndex(size_t) const override;
+  float frameDurationAtIndex(size_t) const override;
+  int repetitionCount() const override;
+  size_t clearCacheExceptFrame(size_t) override;
 
   // Callbacks from libpng
   void headerAvailable();
   void rowAvailable(unsigned char* row, unsigned rowIndex, int);
   void complete();
 
  private:
   // ImageDecoder:
-  void decodeSize() override { decode(true); }
-  void decode(size_t) override { decode(false); }
+  void decodeSize() override { parse(); }
+  void decode(size_t) override;
+  size_t decodeFrameCount() override;
+  void initializeNewFrame(size_t) override;
 
-  // 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);
+  bool initFrameBuffer();
+  bool parse();
 
   std::unique_ptr<PNGImageReader> m_reader;
-  const unsigned m_offset;
+  const size_t m_offset;
+  size_t m_currentFrame;
 };
 
 }  // namespace blink
 
 #endif