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-rw-r--r--image/decoders/nsPNGDecoder.h148
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diff --git a/image/decoders/nsPNGDecoder.h b/image/decoders/nsPNGDecoder.h
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_nsPNGDecoder_h
+#define mozilla_image_decoders_nsPNGDecoder_h
+
+#include "Decoder.h"
+#include "png.h"
+#include "StreamingLexer.h"
+#include "SurfacePipe.h"
+#include "mozilla/gfx/Swizzle.h"
+
+namespace mozilla {
+namespace image {
+class RasterImage;
+
+class nsPNGDecoder : public Decoder {
+ public:
+ virtual ~nsPNGDecoder();
+
+ /// @return true if this PNG is a valid ICO resource.
+ bool IsValidICOResource() const override;
+
+ DecoderType GetType() const override { return DecoderType::PNG; }
+
+ protected:
+ nsresult InitInternal() override;
+ nsresult FinishInternal() override;
+ LexerResult DoDecode(SourceBufferIterator& aIterator,
+ IResumable* aOnResume) override;
+
+ Maybe<Telemetry::HistogramID> SpeedHistogram() const override;
+
+ private:
+ friend class DecoderFactory;
+
+ // Decoders should only be instantiated via DecoderFactory.
+ explicit nsPNGDecoder(RasterImage* aImage);
+
+ /// The information necessary to create a frame.
+ struct FrameInfo {
+ OrientedIntRect mFrameRect;
+ bool mIsInterlaced;
+ };
+
+ nsresult CreateFrame(const FrameInfo& aFrameInfo);
+ void EndImageFrame();
+
+ uint32_t ReadColorProfile(png_structp png_ptr, png_infop info_ptr,
+ int color_type, bool* sRGBTag);
+
+ bool HasAlphaChannel() const { return mChannels == 2 || mChannels == 4; }
+
+ enum class TransparencyType { eNone, eAlpha, eFrameRect };
+
+ TransparencyType GetTransparencyType(const OrientedIntRect& aFrameRect);
+ void PostHasTransparencyIfNeeded(TransparencyType aTransparencyType);
+
+ void PostInvalidationIfNeeded();
+
+ void WriteRow(uint8_t* aRow);
+
+ // Convenience methods to make interacting with StreamingLexer from inside
+ // a libpng callback easier.
+ void DoTerminate(png_structp aPNGStruct, TerminalState aState);
+ void DoYield(png_structp aPNGStruct);
+
+ enum class State { PNG_DATA, FINISHED_PNG_DATA };
+
+ LexerTransition<State> ReadPNGData(const char* aData, size_t aLength);
+ LexerTransition<State> FinishedPNGData();
+
+ StreamingLexer<State> mLexer;
+
+ // The next lexer state transition. We need to store it here because we can't
+ // directly return arbitrary values from libpng callbacks.
+ LexerTransition<State> mNextTransition;
+
+ // We yield to the caller every time we finish decoding a frame. When this
+ // happens, we need to allocate the next frame after returning from the yield.
+ // |mNextFrameInfo| is used to store the information needed to allocate the
+ // next frame.
+ Maybe<FrameInfo> mNextFrameInfo;
+
+ // The length of the last chunk of data passed to ReadPNGData(). We use this
+ // to arrange to arrive back at the correct spot in the data after yielding.
+ size_t mLastChunkLength;
+
+ public:
+ png_structp mPNG;
+ png_infop mInfo;
+ OrientedIntRect mFrameRect;
+ uint8_t* mCMSLine;
+ uint8_t* interlacebuf;
+ gfx::SurfaceFormat mFormat;
+
+ uint8_t mChannels;
+ uint8_t mPass;
+ bool mFrameIsHidden;
+ bool mDisablePremultipliedAlpha;
+ bool mGotInfoCallback;
+ bool mUsePipeTransform;
+
+ struct AnimFrameInfo {
+ AnimFrameInfo();
+#ifdef PNG_APNG_SUPPORTED
+ AnimFrameInfo(png_structp aPNG, png_infop aInfo);
+#endif
+
+ DisposalMethod mDispose;
+ BlendMethod mBlend;
+ int32_t mTimeout;
+ };
+
+ AnimFrameInfo mAnimInfo;
+
+ SurfacePipe mPipe; /// The SurfacePipe used to write to the output surface.
+
+ // The number of frames we've finished.
+ uint32_t mNumFrames;
+
+ // libpng callbacks
+ // We put these in the class so that they can access protected members.
+ static void PNGAPI info_callback(png_structp png_ptr, png_infop info_ptr);
+ static void PNGAPI row_callback(png_structp png_ptr, png_bytep new_row,
+ png_uint_32 row_num, int pass);
+#ifdef PNG_APNG_SUPPORTED
+ static void PNGAPI frame_info_callback(png_structp png_ptr,
+ png_uint_32 frame_num);
+#endif
+ static void PNGAPI end_callback(png_structp png_ptr, png_infop info_ptr);
+ static void PNGAPI error_callback(png_structp png_ptr,
+ png_const_charp error_msg);
+ static void PNGAPI warning_callback(png_structp png_ptr,
+ png_const_charp warning_msg);
+
+ // This is defined in the PNG spec as an invariant. We use it to
+ // do manual validation without libpng.
+ static const uint8_t pngSignatureBytes[];
+};
+
+} // namespace image
+} // namespace mozilla
+
+#endif // mozilla_image_decoders_nsPNGDecoder_h