Add hello_fn2.dart and make Text("Hello fn2") actually render something.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1160843005

examples/fn2/hello_fn2.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 'package:sky/framework/fn2.dart';
+
+class HelloWorldApp extends App {
+  UINode build() {
+    return new Text('Hello, fn2!');
+  }
+}
+
+void main() {
+  new HelloWorldApp();
+}
\ No newline at end of file

sdk/lib/framework/fn2.dart

@@ -543,10 +543,11 @@ class Container extends OneChildListRenderNodeWrapper {
   );
 }
 
-class Paragraph extends OneChildListRenderNodeWrapper {
+class Paragraph extends RenderNodeWrapper {
 
-  RenderCSSParagraph root;
-  RenderCSSParagraph createNode() => new RenderCSSParagraph(this);
+  RenderParagraph root;
+  RenderParagraph createNode() => new RenderParagraph(text);
+  String text;
 
   static final Paragraph _emptyContainer = new Paragraph();
 
@@ -554,11 +555,15 @@ class Paragraph extends OneChildListRenderNodeWrapper {
 
   Paragraph({
     Object key,
-    List<UINode> children
+    this.text
   }) : super(
-    key: key,
-    children: children
+    key: key
   );
+
+  void syncRenderNode(UINode old) {
+    super.syncRenderNode(old);
+    root.text = text;
+  }
 }
 
 class FlexContainer extends OneChildListRenderNodeWrapper {
@@ -646,29 +651,6 @@ abstract class OneChildRenderNodeWrapper extends RenderNodeWrapper {
   }
 }
 
-class TextFragment extends RenderNodeWrapper {
-
-  RenderCSSInline root;
-  RenderCSSInline createNode() => new RenderCSSInline(this, this.data);
-
-  static final TextFragment _emptyText = new TextFragment('');
-
-  RenderNodeWrapper get emptyNode => _emptyText;
-
-  final String data;
-
-  TextFragment(this.data, {
-    Object key
-  }) : super(
-    key: key
-  );
-
-  void syncRenderNode(UINode old) {
-    super.syncRenderNode(old);
-    root.data = data;
-  }
-}
-
 class Image extends RenderNodeWrapper {
 
   RenderCSSImage root;
@@ -936,7 +918,7 @@ class Text extends Component {
   Text(this.data) : super(key: '*text*');
   final String data;
   bool get interchangeable => true;
-  UINode build() => new Paragraph(children: [new TextFragment(data)]);
+  UINode build() => new Paragraph(text: data);
 }
 
 

sdk/lib/framework/layout2.dart

@@ -968,14 +968,20 @@ class RenderFlex extends RenderDecoratedBox with ContainerRenderNodeMixin<Render
   }
 }
 
+class RenderInline extends RenderNode {
+  String data;
+
+  RenderInline(this.data);
+}
+
 class RenderParagraph extends RenderDecoratedBox {
-  final String text;
-  LayoutRoot _layoutRoot = new LayoutRoot();
-  Document _document;
+  String text;
+  sky.LayoutRoot _layoutRoot = new sky.LayoutRoot();
+  sky.Document _document;
 
   RenderParagraph(String this.text) :
    super(new BoxDecoration(backgroundColor: 0xFFFFFFFF)) {
-    _document = new Document();
+    _document = new sky.Document();
     _layoutRoot.rootElement = _document.createElement('p');
     _layoutRoot.rootElement.appendChild(_document.createText(this.text));
   }
@@ -983,9 +989,12 @@ class RenderParagraph extends RenderDecoratedBox {
   void performLayout() {
     _layoutRoot.maxWidth = constraints.maxWidth;
     _layoutRoot.minWidth = constraints.minWidth;
+    _layoutRoot.minHeight = constraints.minHeight;
+    _layoutRoot.maxHeight = constraints.maxHeight;
     _layoutRoot.layout();
     width = _layoutRoot.rootElement.width;
-    height = _layoutRoot.rootElement.height;
+    // TODO(eseidel): LayoutRoot will not expand to fill height. :(
+    height = _constraints.constrainHeight(_layoutRoot.rootElement.height);
   }
 
   void hitTestChildren(HitTestResult result, { double x, double y }) {