Implement ClipRRect

sky/sdk/lib/rendering/box.dart

Index: sky/sdk/lib/rendering/box.dart
diff --git a/sky/sdk/lib/rendering/box.dart b/sky/sdk/lib/rendering/box.dart
index 36d700aee1fdbfdd35f625c4cb84e58403955d24..13394da5d5fb80525dd52e36fdf069c7e89a844f 100644
--- a/sky/sdk/lib/rendering/box.dart
+++ b/sky/sdk/lib/rendering/box.dart
@@ -556,6 +556,26 @@ class RenderClipRect extends RenderProxyBox {
   }
 }
 
+class RenderClipRRect extends RenderProxyBox {
+  final double xRad;
+  final double yRad;

[abarth-chromium, 2015/06/25 17:11:21]

xRadius and yRadius

Please use complete words in variable names.

Also, these shouldn't be final.  They should have setters that compare the new
value to the existing value and call markNeedsPaint if the value changes.

[Hixie, 2015/06/25 17:16:58]

also, constructors first. fields second or with the code that uses them.

+  RenderClipRRect({ RenderBox child, this.xRad, this.yRad }) : super(child) {
+    assert(xRad != null);
+    assert(yRad != null);
+  }
+
+  void paint(RenderCanvas canvas) {
+    if (child != null) {
+      Rect rect = new Rect.fromSize(size);
+      canvas.saveLayer(rect, new Paint());
+      sky.RRect rrect = new sky.RRect()..setRectXY(rect, xRad, yRad);

[Hixie, 2015/06/25 17:16:59]

Doesn't RRect() have a suitable constructor?

Indeed, why isn't RRect immutable?

+      canvas.clipRRect(rrect);

[Hixie, 2015/06/25 17:16:59]

What's the anti-aliasing story here?

(ok, trick question, we talked about this. But we should contact Skia people
about it.)

+      child.paint(canvas);
+      canvas.restore();
+    }
+  }
+}
+
 class RenderClipOval extends RenderProxyBox {
   RenderClipOval({ RenderBox child }) : super(child);