Animated PNG implementation

third_party/WebKit/Source/platform/image-decoders/png/PNGImageReader.h

Index: third_party/WebKit/Source/platform/image-decoders/png/PNGImageReader.h
diff --git a/third_party/WebKit/Source/platform/image-decoders/png/PNGImageReader.h b/third_party/WebKit/Source/platform/image-decoders/png/PNGImageReader.h
index 4144201a9b66088d12704bdf2d64feb9eac6c822..eea2106852f09406221ebef1fba3e8ef3c37070c 100644
--- a/third_party/WebKit/Source/platform/image-decoders/png/PNGImageReader.h
+++ b/third_party/WebKit/Source/platform/image-decoders/png/PNGImageReader.h
@@ -52,14 +52,52 @@ class PLATFORM_EXPORT PNGImageReader final {
   PNGImageReader(PNGImageDecoder*, size_t offset);
   ~PNGImageReader();
 
-  bool decode(const SegmentReader&, bool sizeOnly);
+  struct FrameInfo {
+    size_t start;
+    size_t finish;
+    png_uint_32 width;
+    png_uint_32 height;
+    png_uint_32 xOffset;
+    png_uint_32 yOffset;
+    unsigned duration;
+    unsigned dispose;
+    unsigned blend;
+  };
+
+  inline void processData(const SegmentReader& data,
+                          size_t index,
+                          size_t offset,
+                          size_t endOffset) {
+    const char* segment;
+    while (size_t segmentLength = data.getSomeData(segment, offset)) {
+      if (endOffset && offset + segmentLength > endOffset)
+        segmentLength = endOffset - offset;
+
+      offset += segmentLength;
+      png_process_data(m_png, m_info,
+                       reinterpret_cast<png_bytep>(const_cast<char*>(segment)),
+                       segmentLength);
+
+      if (offset == endOffset)
+        break;
+    }
+    if (!index)
+      m_decodeOffset = offset;
+  }
+
+  bool parse(SegmentReader&);
+  bool decode(SegmentReader&, size_t index);
   png_structp pngPtr() const { return m_png; }
   png_infop infoPtr() const { return m_info; }
 
-  size_t getReadOffset() const { return m_readOffset; }
-  void setReadOffset(size_t offset) { m_readOffset = offset; }
-  size_t currentBufferSize() const { return m_currentBufferSize; }
-  bool decodingSizeOnly() const { return m_decodingSizeOnly; }
+  int repetitionCount() const { return m_repetitionCount; }
+  size_t imagesCount() const {
+    return m_frames.isEmpty() ? 1 : m_frames.size() - m_posterFrame;
+  }
+  const FrameInfo* frameInfo(size_t index) const {
+    return m_frames.isEmpty() ? &m_currentFrame
+                              : &m_frames[index + m_posterFrame];
+  }
   void setHasAlpha(bool hasAlpha) { m_hasAlpha = hasAlpha; }
   bool hasAlpha() const { return m_hasAlpha; }
 
@@ -73,8 +111,18 @@ class PLATFORM_EXPORT PNGImageReader final {
   png_infop m_info;
   PNGImageDecoder* m_decoder;
   size_t m_readOffset;
-  size_t m_currentBufferSize;
-  bool m_decodingSizeOnly;
+  size_t m_parseOffset;
+  size_t m_decodeOffset;
+  size_t m_infoSize;
+  bool m_isAnimated;
+  bool m_isParsed;
+  png_uint_32 m_width;
+  png_uint_32 m_height;
+  int m_repetitionCount;
+  size_t m_posterFrame;
+  size_t m_visibleFrames;
+  FrameInfo m_currentFrame;
+  Vector<FrameInfo> m_frames;
   bool m_hasAlpha;
   std::unique_ptr<png_byte[]> m_interlaceBuffer;
 };