Make the search box in the stocks app show a search field

sky/examples/stocks-fn/stocksapp.dart

 library stocksapp;
 
 import '../../framework/fn.dart';
 import '../../framework/components/drawer.dart';
 import '../../framework/components/drawer_header.dart';
 import '../../framework/components/fixed_height_scrollable.dart';
 import '../../framework/components/floating_action_button.dart';
 import '../../framework/components/icon.dart';
+import '../../framework/components/input.dart';
 import '../../framework/components/material.dart';
 import '../../framework/components/menu_divider.dart';
 import '../../framework/components/menu_item.dart';
 import '../../framework/components/toolbar.dart';
 import '../data/stocks.dart';
 import 'dart:math';
 
 part 'stockarrow.dart';
 part 'stocklist.dart';
 part 'stockrow.dart';
@@ skipping 14 matching lines @@
     padding: 8px;
     margin: 0 4px;'''
   );
 
   static Style _titleStyle = new Style('''
     flex: 1;
     margin: 0 4px;'''
   );
 
   List<Stock> _sortedStocks;
+  bool _isSearching = false;
 
   StocksApp() : super() {
     _sortedStocks = oracle.stocks;
     _sortedStocks.sort((a, b) => a.symbol.compareTo(b.symbol));
   }
 
+  void _handleSearchClick(_) {
+    setState(() {
+      _isSearching = !_isSearching;
+    });
+  }
+
   Node build() {
     var drawer = new Drawer(
       animation: _drawerAnimation,
       children: [
         new DrawerHeader(
           children: [new Text('Stocks')]
         ),
         new MenuItem(
           key: 'Inbox',
           icon: 'content/inbox',
@@ skipping 12 matching lines @@
           children: [new Text('Settings')]
         ),
         new MenuItem(
           key: 'Help & Feedback',
           icon: 'action/help',
           children: [new Text('Help & Feedback')]
         )
       ]
     );
 
+    Node title = _isSearching ?
+        new Input(focused: true) : new Text('I am a stocks app');
+
     var toolbar = new Toolbar(
       children: [
         new Icon(key: 'menu', style: _iconStyle,
             size: 24,
             type: 'navigation/menu_white')
           ..events.listen('click', _drawerAnimation.toggle),
         new Container(
           style: _titleStyle,
-          children: [new Text('I am a stocks app')]
+          children: [title]
         ),
         new Icon(key: 'search', style: _iconStyle,
             size: 24,
-            type: 'action/search_white'),
+            type: 'action/search_white')
+          ..events.listen('click', _handleSearchClick),
         new Icon(key: 'more_white', style: _iconStyle,
             size: 24,
             type: 'navigation/more_vert_white')
       ]
     );
 
     var fab = new FloatingActionButton(content: new Icon(
       type: 'content/add_white', size: 24));
 
     return new Container(
       key: 'StocksApp',
       children: [
         new Container(
           key: 'Content',
           style: _style,
           children: [toolbar, new Stocklist(stocks: _sortedStocks)]
         ),
         fab,
         drawer,
       ]
     );
   }
 }