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

sky/sdk/lib/framework/rendering/object.dart

Index: sky/sdk/lib/framework/rendering/object.dart
diff --git a/sky/sdk/lib/framework/rendering/object.dart b/sky/sdk/lib/framework/rendering/object.dart
index 4f8173237604b63eea1b376d750bae5881314ec0..b528a598fb3e075b0bc8b27f31b355bfde93b62f 100644
--- a/sky/sdk/lib/framework/rendering/object.dart
+++ b/sky/sdk/lib/framework/rendering/object.dart
@@ -25,15 +25,6 @@ class ParentData {
 
 const kLayoutDirections = 4;
 
-class RenderObjectDisplayList extends sky.PictureRecorder {
-  RenderObjectDisplayList(double width, double height) : super(width, height);
-  void paintChild(RenderObject child, Point position) {
-    translate(position.x, position.y);
-    child.paint(this);
-    translate(-position.x, -position.y);
-  }
-}
-
 abstract class RenderObject extends AbstractNode {
 
   // LAYOUT
@@ -50,6 +41,12 @@ abstract class RenderObject extends AbstractNode {
       child.parentData = new ParentData();
   }
 
+  void paintChild(sky.Canvas canvas, RenderObject child, Point position) {
+    canvas.translate(position.x, position.y);
+    child.paint(canvas);
+    canvas.translate(-position.x, -position.y);
+  }
+

[Hixie, 2015/06/18 00:07:09]

I really don't like this change. It is going to encourage people to just call
child.paint(canvas) instead of paintChild(canvas).

The reason behind canvas.paintChild(child) is that it will subsequently let us
change whether or not a node painting a child introduces a new
canvas/displaylist/recorder/whatever without having to change any of the call
sites.

[iansf, 2015/06/20 00:02:38]

Let me know what you think of the new version.

   void adoptChild(RenderObject child) { // only for use by subclasses
     // call this whenever you decide a node is a child
     assert(!debugDoingLayout);
@@ -201,7 +198,7 @@ abstract class RenderObject extends AbstractNode {
     assert(!debugDoingPaint);
     scheduler.ensureVisualUpdate();
   }
-  void paint(RenderObjectDisplayList canvas) { }
+  void paint(sky.Canvas canvas) { }
 
 
   // EVENTS