Sky support for flexbox justify content

R=abarth@chromium.org, abarth

Review URL: https://codereview.chromium.org/1164363002

examples/lib/solid_color_box.dart

@@ -9,7 +9,7 @@ class RenderSolidColorBox extends RenderDecoratedBox {
   final Size desiredSize;
   final Color backgroundColor;
 
-  RenderSolidColorBox(Color backgroundColor, { this.desiredSize: const Size.infinite() })
+  RenderSolidColorBox(Color backgroundColor, { this.desiredSize: Size.infinite })
       : backgroundColor = backgroundColor,
         super(decoration: new BoxDecoration(backgroundColor: backgroundColor));
 

examples/raw/justify_content.dart

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:sky';
+import 'dart:math' as math;
+import 'package:sky/framework/app.dart';
+import 'package:sky/framework/rendering/box.dart';
+import 'package:sky/framework/rendering/block.dart';
+import 'package:sky/framework/rendering/flex.dart';
+import 'package:sky/framework/rendering/object.dart';
+import 'package:sky/framework/rendering/paragraph.dart';
+import '../lib/solid_color_box.dart';
+
+AppView app;
+
+// Attempts to draw
+// http://www.w3.org/TR/2015/WD-css-flexbox-1-20150514/images/flex-pack.svg
+void main() {
+  var table = new RenderFlex(direction: FlexDirection.vertical);
+
+  void addRow(FlexJustifyContent justify) {
+    RenderParagraph paragraph = new RenderParagraph(text: "${justify}");
+    table.add(new RenderPadding(child: paragraph, padding: new EdgeDims.only(top: 20.0)));
+    var row = new RenderFlex(direction: FlexDirection.horizontal);
+    row.add(new RenderSolidColorBox(const Color(0xFFFFCCCC), desiredSize: new Size(80.0, 60.0)));
+    row.add(new RenderSolidColorBox(const Color(0xFFCCFFCC), desiredSize: new Size(64.0, 60.0)));
+    row.add(new RenderSolidColorBox(const Color(0xFFCCCCFF), desiredSize: new Size(160.0, 60.0)));
+    row.justifyContent = justify;
+    table.add(row);
+    row.parentData.flex = 1;
+  }
+
+  addRow(FlexJustifyContent.flexStart);
+  addRow(FlexJustifyContent.flexEnd);
+  addRow(FlexJustifyContent.center);
+  addRow(FlexJustifyContent.spaceBetween);
+  addRow(FlexJustifyContent.spaceAround);
+
+  RenderDecoratedBox root = new RenderDecoratedBox(
+    decoration: new BoxDecoration(backgroundColor: const Color(0xFFFFFFFF)),
+    child: new RenderPadding(child: table, padding: new EdgeDims.symmetric(vertical: 50.0))
+  );
+
+  app = new AppView(root);
+}