Decouple Canvas from DisplayList and map Picture and PictureRecorder more directly to their Skia co…

sky/examples/raw/hello_world.dart

Index: sky/examples/raw/hello_world.dart
diff --git a/sky/examples/raw/hello_world.dart b/sky/examples/raw/hello_world.dart
index 4264abf8990f0bee5c78ce2d5bad6f70456e9ee3..89f49188d3c6ee61351d0edd91cc34a5c2080587 100644
--- a/sky/examples/raw/hello_world.dart
+++ b/sky/examples/raw/hello_world.dart
@@ -5,15 +5,18 @@
 import "dart:math";
 import 'dart:sky';
 
+import 'package:sky/rendering/object.dart';

[abarth-chromium, 2015/06/23 02:28:45]

This demo shouldn't depend on package:sky.  It's meant to be a minimal example
of programming the raw dart:sky engine.

[iansf, 2015/06/23 22:46:09]

Done.

+
 Picture draw(int a, int r, int g, int b) {
   double width = view.width;
   double height = view.height;
 
-  PictureRecorder recorder = new PictureRecorder(width, height);
+  PictureRecorder recorder = new PictureRecorder();
+  RenderCanvas canvas = new RenderCanvas(recorder, width, height);

[abarth-chromium, 2015/06/23 02:28:45]

You can just use regular Canvas here.

[iansf, 2015/06/23 22:46:09]

Done.

   double radius = min(width, height) * 0.45;
 
   Paint paint = new Paint()..color = new Color.fromARGB(a, r, g, b);
-  recorder.drawCircle(width / 2, height / 2, radius, paint);
+  canvas.drawCircle(width / 2, height / 2, radius, paint);
   return recorder.endRecording();
 }