Move example fn widgets into sky/framework/components

sky/framework/components/material.dart

-part of widgets;
+// 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.
 
-abstract class MaterialComponent extends Component {
+import '../fn.dart';
+import 'dart:sky' as sky;
+import 'dart:collection';
+import 'ink_splash.dart';
 
+abstract class Material extends Component {
   static const _splashesKey = const Object();
 
-  static Style _style = new Style('''
+  static final Style _style = new Style('''
     transform: translateX(0);
     position: absolute;
     top: 0;
     left: 0;
     right: 0;
     bottom: 0'''
   );
 
   LinkedHashSet<SplashAnimation> _splashes;
 
-  MaterialComponent({ Object key }) : super(key: key);
+  Material({ Object key }) : super(key: key) {
+    events.listen('gesturescrollstart', _cancelSplashes);
+    events.listen('wheel', _cancelSplashes);
+    events.listen('pointerdown', _startSplash);
+  }
 
   Node build() {
     List<Node> children = [];
 
     if (_splashes != null) {
       children.addAll(_splashes.map((s) => new InkSplash(s.onStyleChanged)));
     }
 
     return new Container(
       style: _style,
       children: children,
       key: _splashesKey
-    )..events.listen('gesturescrollstart', _cancelSplashes)
-     ..events.listen('wheel', _cancelSplashes)
-     ..events.listen('pointerdown', _startSplash);
+    );
   }
 
   sky.ClientRect _getBoundingRect() => (getRoot() as sky.Element).getBoundingClientRect();
 
   void _startSplash(sky.PointerEvent event) {
     setState(() {
       if (_splashes == null) {
         _splashes = new LinkedHashSet<SplashAnimation>();
       }
 
@@ skipping 27 matching lines @@
     }
 
     setState(() {
       _splashes.remove(splash);
       if (_splashes.length == 0) {
         _splashes = null;
       }
     });
   }
 }