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Diffstat (limited to 'include/core/SkPngChunkReader.h')
-rw-r--r-- | include/core/SkPngChunkReader.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/include/core/SkPngChunkReader.h b/include/core/SkPngChunkReader.h new file mode 100644 index 0000000000..f424dd8cfc --- /dev/null +++ b/include/core/SkPngChunkReader.h @@ -0,0 +1,45 @@ +/* + * 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 "SkTypes.h" +#include "SkRefCnt.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 SkImageDecoder and 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 |