1 /* 2 * Copyright 2024 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 #ifndef SkPngCompositeChunkReader_DEFINED 8 #define SkPngCompositeChunkReader_DEFINED 9 10 #include "include/codec/SkPngChunkReader.h" 11 #include "include/core/SkRefCnt.h" 12 #include "include/core/SkStream.h" 13 #include "include/private/SkGainmapInfo.h" 14 15 #include <cstddef> 16 #include <memory> 17 #include <optional> 18 #include <utility> 19 20 /** 21 * Reader for PNG chunks that handles the composite of: 22 * 1. Chunks currently unknown to the PNG spec, but are necessary to correctly 23 * decode certain images. For example, images that contain gainmap chunks. 24 * 2. Client-provided callbacks that may listen to other unknown chunks. 25 * 26 * The PNG api can only register one callback for unknown chunks at a time, 27 * hence this wrapper class. 28 */ 29 class SkPngCompositeChunkReader : public SkPngChunkReader { 30 public: SkPngCompositeChunkReader(SkPngChunkReader * chunkReader)31 explicit SkPngCompositeChunkReader(SkPngChunkReader* chunkReader) 32 : fChunkReader(SkSafeRef(chunkReader)) {} 33 34 bool readChunk(const char tag[], const void* data, size_t length) override; 35 takeGaimapStream()36 std::unique_ptr<SkStream> takeGaimapStream() { return std::move(fGainmapStream); } 37 getGainmapInfo()38 std::optional<SkGainmapInfo> getGainmapInfo() const { return fGainmapInfo; } 39 40 private: 41 sk_sp<SkPngChunkReader> fChunkReader = nullptr; 42 std::optional<SkGainmapInfo> fGainmapInfo; 43 std::unique_ptr<SkStream> fGainmapStream = nullptr; 44 }; 45 46 #endif // SkPngCompositeChunkReader_DEFINED 47