Prototype of RAW decoding in Skia.

src/codec/SkRawCodec.h

+/*
+ * 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 SkRawCodec_DEFINED
+#define SkRawCodec_DEFINED
+
+#include "SkCodec.h"
+#include "SkImageInfo.h"
+#include "SkTypes.h"
+
+class dng_stream;
+class dng_host;
+class dng_image;
+class dng_info;
+class dng_negative;
+class SkStream;
+class SkRawStream;
+
+/*
+ *
+ * This class implements the decoding for RAW images
+ *
+ */
+class SkRawCodec : public SkCodec {
+public:
+
+    /*
+     * Creates a RAW decoder
+     * Takes ownership of the stream
+     */
+    static SkCodec* NewFromStream(SkStream*);
+
+    ~SkRawCodec() override;
+
+protected:
+
+    /*
+     * Supports only requests, which take the size from onGetScaledDimensions().

[scroggo, 2016/01/12 21:54:39]

I thought you had decided to support other requests?

If this comment is necessary, though, it needs to also be in SkCodec.h on
getScaledDimensions. This is a virtual function, so a client might be calling it
on a pointer to SkCodec.

Also, nit: Unnecessary comma.

[yujieqin, 2016/01/13 15:29:42]

You are right, it is misleading. Removed.

+     */
+    Result onGetPixels(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes, const Options&,
+            SkPMColor*, int*, int*) override;
+
+    SkEncodedFormat onGetEncodedFormat() const override {
+        return kRAW_SkEncodedFormat;
+    }
+
+    SkISize onGetScaledDimensions(float desiredScale) const override;
+
+    bool onDimensionsSupported(const SkISize&) override;
+
+private:
+
+    /*
+     * Creates an instance of the decoder
+     * Called only by NewFromStream, takes ownership of all of its pointer parameters.
+     */
+    SkRawCodec(const SkImageInfo& srcInfo, SkRawStream* stream, dng_host* host, dng_info* info,
+               dng_negative* negative);
+
+    SkRawStream* fRawStream;
+
+    mutable SkAutoTDelete<dng_host> fDngHost;
+    mutable SkAutoTDelete<dng_image> fDngImage;
+    mutable SkAutoTDelete<dng_info> fDngInfo;
+    mutable SkAutoTDelete<dng_negative> fDngNegative;
+
+    typedef SkCodec INHERITED;
+};
+
+#endif