Delete drawerController and make drawer handle back behavior natively

sky/sdk/example/stocks/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/animation/animation_performance.dart';
 import 'package:sky/widgets/animated_component.dart';
 import 'package:sky/widgets/animation_builder.dart';
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/widgets/basic.dart';
@@ skipping 19 matching lines @@
 import 'stock_list.dart';
 import 'stock_menu.dart';
 import 'stock_types.dart';
 
 typedef void ModeUpdater(StockMode mode);
 
 const Duration _kSnackbarSlideDuration = const Duration(milliseconds: 200);
 
 class StockHome extends AnimatedComponent {
 
-  StockHome(this.navigator, this.stocks, this.stockMode, this.modeUpdater) {
-    // if (debug)
-    //   new Timer(new Duration(seconds: 1), dumpState);
-    _drawerController = new DrawerController(_handleDrawerStatusChanged);
-  }
+  StockHome(this.navigator, this.stocks, this.stockMode, this.modeUpdater);
 
   Navigator navigator;
   List<Stock> stocks;
   StockMode stockMode;
   ModeUpdater modeUpdater;
 
   void syncFields(StockHome source) {
     navigator = source.navigator;
     stocks = source.stocks;
     stockMode = source.stockMode;
@@ skipping 26 matching lines @@
       _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();
       _menuController.open();
     });
   }
 
   void _handleMenuHide() {
@@ skipping 16 matching lines @@
   void _handleStockModeChange(StockMode value) {
     setState(() {
       stockMode = value;
     });
     if (modeUpdater != null)
       modeUpdater(value);
   }
 
   Drawer buildDrawer() {
     return new Drawer(
-      controller: _drawerController,
       level: 3,
+      showing: _drawerShowing,
+      onStatusChange: _handleDrawerStatusChange,
+      navigator: navigator,
       children: [
         new DrawerHeader(children: [new Text('Stocks')]),
         new MenuItem(
           icon: 'action/assessment',
           selected: true,
           children: [new Text('Stock List')]),
         new MenuItem(
           icon: 'action/account_balance',
           children: [new Text('Account Balance')]),
         new MenuDivider(),
@@ skipping 16 matching lines @@
           icon: 'action/settings',
           onPressed: _handleShowSettings,
           children: [new Text('Settings')]),
         new MenuItem(
           icon: 'action/help',
           children: [new Text('Help & Feedback')])
      ]
     );
   }
 
+  void _handleDrawerStatusChange(bool showing) {
+    setState(() {
+      _drawerShowing = showing;
+    });
+  }
+
   void _handleShowSettings() {
-    assert(navigator.currentRoute.name == '/drawer');
     navigator.pop();
-    assert(navigator.currentRoute.name == '/');
     navigator.pushNamed('/settings');
   }
 
   void _handleOpenDrawer() {
-    _drawerController.open();
-    navigator.pushState("/drawer", (_) {
-      _drawerController.close();
+    setState(() {
+      _drawerShowing = true;
     });
   }
 
   Widget buildToolBar() {
     return new ToolBar(
         left: new IconButton(
           icon: "navigation/menu",
           onPressed: _handleOpenDrawer),
         center: new Text('Stocks'),
         right: [
@@ skipping 116 matching lines @@
       onDismiss: _handleMenuHide));
   }
 
   Widget build() {
     List<Widget> overlays = [
       new Scaffold(
         toolbar: _isSearching ? buildSearchBar() : buildToolBar(),
         body: buildTabNavigator(),
         snackBar: buildSnackBar(),
         floatingActionButton: buildFloatingActionButton(),
-        drawer: _drawerShowing ? buildDrawer() : null

[abarth-chromium, 2015/07/14 16:55:10]

You're building the drawer unconditionally....  It would be better not to have
to do this work if we're not going to show the drawer.

+        drawer: buildDrawer()
       ),
     ];
     addMenuToOverlays(overlays);
     return new Stack(overlays);
   }
 }