Specs: Simplify the paint model. Now you are not responsible for

sky/examples/style/toolbar-layout.sky

 SKY MODULE
 <import src="sky:core" as="sky"/>
 <script>
  // display: toolbar;
  // toolbar-spacing: <length>
  // display: spring; // remaining space is split equally amongst the springs
  // children are vertically centered, layout out left-to-right with toolbar-spacing space between them
  // last child is hidden by default unless there's not enough room for the others, then it's shown last, right-aligned
  module.exports.SpringLayoutManager = class SpringLayoutManager extends sky.LayoutManager { }
  sky.registerLayoutManager('spring', module.exports.SpringLayoutManager);
@@ skipping 170 matching lines @@
        result.value = result.maximum;
      if (result.value < result.minimum)
        result.value = result.minimum;
      return result;
    }
    function paintChildren(canvas) {
      let width = this.node.width;
      let children = this.walkChildren();
      let loop = children.next();
      while ((!loop.done) && (loop.value != this.firstSkippedChild))
-       this.paintChild(loop.value, canvas);
+       canvas.paintChild(loop.value);
      if (this.showingOverflow)
-       this.paintChild(this.overflowChild, canvas);
+       canvas.paintChild(this.overflowChild);
    }
    function inChild(child, x, y) {
      return (x >= child.x) && (y >= child.y) && (x < child.x+child.width) && (y < child.y+child.height);
    }
    function hitTest(x, y) {
      let children = this.walkChildrenBackwards();
      let loop = children.next();
      while ((!loop.done) && (loop.value != this.firstSkippedChild))
        if (this.inChild(loop.value, x, y))
          return loop.value;
      if (this.showingOverflow)
        if (this.inChild(this.overflowChild, x, y))
          return this.overflowChild;
    }
  }
  sky.registerLayoutManager('toolbar', module.exports.ToolbarLayoutManager);
 </script>