Implement a floating action button in fn

sky/examples/fn/widgets/style_component.dart

Index: sky/examples/fn/widgets/style_component.dart
diff --git a/sky/examples/fn/widgets/style_component.dart b/sky/examples/fn/widgets/style_component.dart
new file mode 100644
index 0000000000000000000000000000000000000000..fb18c52e86ea266d8b325c2b050ca6c969125182
--- /dev/null
+++ b/sky/examples/fn/widgets/style_component.dart
@@ -0,0 +1,17 @@
+part of widgets;
+
+abstract class StyleComponent extends Component {
+  Node content;
+
+  // Subclasses should implement this getter to provide their style information.
+  Style get style => null;
+
+  StyleComponent({ Object key, this.content }) : super(key: key);
+
+  Node render() {
+    return new Container(
+      style: style,
+      children: content == null ? [] : [content]
+    );
+  }
+}