Provides multiple implementations of Android's SkBitmapRegionDecoder

src/utils/SkBitmapRegionDecoder.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 SkBitmapRegionDecoder_DEFINED
+#define SkBitmapRegionDecoder_DEFINED
+
+#include "SkBitmap.h"
+#include "SkStream.h"
+
+/*
+ * This class aims to provide an interface to test multiple implementations of
+ * SkBitmapRegionDecoder.
+ */
+class SkBitmapRegionDecoder {
+public:
+
+    enum Strategy {
+        kCanvas_Strategy,
+        kSample_Strategy,

[scroggo, 2015/08/13 16:53:07]

So this uses SkImageDecoder?

[msarett, 2015/08/13 18:10:23]

Yeah - I think there will be a Sample strategy for ImageDecoder and Codec once
Emmalee's change lands.  I will go ahead and change the name now.

Maybe something like Baseline or Original - so we can compare all of the Codec
versions to the old version.

+        // TODO (msarett): Add strategy for SkScaledCodec
+    };
+
+    static SkBitmapRegionDecoder* CreateBitmapRegionDecoder(
+            SkStreamRewindable* stream, Strategy strategy);
+
+    virtual SkBitmap* decodeRegion(int start_x, int start_y, int width,

[scroggo, 2015/08/13 16:53:07]

comments?

[msarett, 2015/08/13 18:10:23]

Adding comments!

+                                   int height, int sampleSize,
+                                   SkColorType prefColorType) = 0;
+
+    int width() const { return fWidth; }
+    int height() const { return fHeight; }
+
+    virtual ~SkBitmapRegionDecoder() {}
+
+protected:
+
+    SkBitmapRegionDecoder(int width, int height)
+        : fWidth(width)
+        , fHeight(height)
+    {}
+
+private:
+    int fWidth;

[scroggo, 2015/08/13 16:53:07]

Can these be const?

[msarett, 2015/08/13 18:10:23]

Yes!

+    int fHeight;
+};
+
+#endif