/* * Copyright 2015 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #ifndef SkPngChunkReader_DEFINED #define SkPngChunkReader_DEFINED #include "include/core/SkRefCnt.h" #include "include/core/SkTypes.h" /** * SkPngChunkReader * * Base class for optional callbacks to retrieve meta/chunk data out of a PNG * encoded image as it is being decoded. * Used by SkCodec. */ class SkPngChunkReader : public SkRefCnt { public: /** * This will be called by the decoder when it sees an unknown chunk. * * Use by SkCodec: * Depending on the location of the unknown chunks, this callback may be * called by * - the factory (NewFromStream/NewFromData) * - getPixels * - startScanlineDecode * - the first call to getScanlines/skipScanlines * The callback may be called from a different thread (e.g. if the SkCodec * is passed to another thread), and it may be called multiple times, if * the SkCodec is used multiple times. * * @param tag Name for this type of chunk. * @param data Data to be interpreted by the subclass. * @param length Number of bytes of data in the chunk. * @return true to continue decoding, or false to indicate an error, which * will cause the decoder to not return the image. */ virtual bool readChunk(const char tag[], const void* data, size_t length) = 0; }; #endif // SkPngChunkReader_DEFINED