Make back button control drawer in stocks app

sky/examples/stocks2/lib/stock_home.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/editing/input.dart';
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/theme/typography.dart' as typography;
 import 'package:sky/widgets/basic.dart';
 import 'package:sky/widgets/drawer.dart';
 import 'package:sky/widgets/drawer_header.dart';
@@ skipping 11 matching lines @@
 import 'package:sky/widgets/widget.dart';
 
 import 'stock_data.dart';
 import 'stock_list.dart';
 import 'stock_menu.dart';
 
 enum StockMode { optimistic, pessimistic }
 
 class StockHome extends Component {
 
-  StockHome(this._navigator) {
+  StockHome(this.navigator, RouteBase route, this.stocks) : super(stateful: true) {
     // if (debug)
     //   new Timer(new Duration(seconds: 1), dumpState);
-    new StockDataFetcher((StockData data) {
-      setState(() {
-        data.appendTo(_stocks);
-      });
-    });
     _drawerController = new DrawerController(_handleDrawerStatusChanged);
   }
 
-  List<Stock> _stocks = [];
-  Navigator _navigator;
+  void syncFields(StockHome source) {
+    navigator = source.navigator;
+    stocks = source.stocks;
+  }
+
+  Navigator navigator;
+  List<Stock> stocks;
 
   bool _isSearching = false;
   String _searchQuery;
 
   void _handleSearchBegin() {
     setState(() {
       _isSearching = true;
     });
   }
 
   void _handleSearchEnd() {
     setState(() {
       _isSearching = false;
       _searchQuery = null;
     });
   }
 
   void _handleSearchQueryChanged(String query) {
     setState(() {
       _searchQuery = query;
     });
   }
 
   DrawerController _drawerController;
   bool _drawerShowing = false;
 
   void _handleDrawerStatusChanged(bool showing) {
+    if (!showing && navigator.currentRoute.name == "/drawer") {
+      navigator.pop();
+    }
     setState(() {
       _drawerShowing = showing;
     });
   }
 
   PopupMenuController _menuController;
 
   void _handleMenuShow() {
     setState(() {
       _menuController = new PopupMenuController();
@@ skipping 48 matching lines @@
         new MenuItem(
           icon: 'action/thumb_down',
           onPressed: () => _handleStockModeChange(StockMode.pessimistic),
           children: [
             new Flexible(child: new Text('Pessimistic')),
             new Radio(value: StockMode.pessimistic, groupValue: _stockMode, onChanged: _handleStockModeChange)
           ]),
         new MenuDivider(),
         new MenuItem(
           icon: 'action/settings',
-          onPressed: () => _navigator.pushNamed('/settings'),
+          onPressed: () => navigator.pushNamed('/settings'),
           children: [new Text('Settings')]),
         new MenuItem(
           icon: 'action/help',
           children: [new Text('Help & Feedback')])
      ]
     );
   }
 
+  void _handleOpenDrawer() {
+    _drawerController.open();
+    navigator.pushState("/drawer", (_) {
+      _drawerController.close();
+    });
+  }
+
   Widget buildToolBar() {
     return new ToolBar(
         left: new IconButton(
           icon: 'navigation/menu_white',
-          onPressed: _drawerController.toggle),
+          onPressed: _handleOpenDrawer),
         center: new Text('Stocks', style: typography.white.title),
         right: [
           new IconButton(
             icon: 'action/search_white',
             onPressed: _handleSearchBegin),
           new IconButton(
             icon: 'navigation/more_vert_white',
             onPressed: _handleMenuShow)
         ],
         backgroundColor: colors.Purple[500]
@@ skipping 23 matching lines @@
         autorefresh: _autorefresh,
         onAutorefreshChanged: _handleAutorefreshChanged
       )],
       onDismiss: _handleMenuHide));
   }
 
   Widget build() {
     List<Widget> overlays = [
       new Scaffold(
         toolbar: _isSearching ? buildSearchBar() : buildToolBar(),
-        body: new Stocklist(stocks: _stocks, query: _searchQuery),
+        body: new Stocklist(stocks: stocks, query: _searchQuery),
         floatingActionButton: new FloatingActionButton(
           child: new Icon(type: 'content/add_white', size: 24)
         ),
         drawer: _drawerShowing ? buildDrawer() : null
       ),
     ];
     addMenuToOverlays(overlays);
     return new Stack(overlays);
   }
 }