Change how events are handled in Effen

sky/examples/stocks-fn/lib/stock_app.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/framework/components/action_bar.dart';
 import 'package:sky/framework/components/drawer.dart';
 import 'package:sky/framework/components/drawer_header.dart';
 import 'package:sky/framework/components/floating_action_button.dart';
 import 'package:sky/framework/components/icon.dart';
 import 'package:sky/framework/components/input.dart';
 import 'package:sky/framework/components/menu_divider.dart';
 import 'package:sky/framework/components/menu_item.dart';
 import 'package:sky/framework/components/popup_menu.dart';
 import 'package:sky/framework/fn.dart';
 import 'package:sky/framework/theme/typography.dart' as typography;
 import 'stock_data.dart';
 import 'stock_list.dart';
 import 'stock_menu.dart';
 
 class StocksApp extends App {
 
   DrawerController _drawerController = new DrawerController();
-  PopupMenuController _menuController = new PopupMenuController();
+  PopupMenuController _menuController;
 
   static Style _style = new Style('''
     display: flex;
     flex-direction: column;
     height: -webkit-fill-available;
     ${typography.typeface};
     ${typography.black.body1};'''
   );
 
   static Style _iconStyle = new Style('''
@@ skipping 17 matching lines @@
   }
 
   void _handleSearchClick(_) {
     setState(() {
       _isSearching = !_isSearching;
     });
   }
 
   void _handleMenuClick(_) {
     setState(() {
+      _menuController = new PopupMenuController();
       _menuController.open();
     });
   }
 
   void _handleSearchQueryChanged(query) {
     setState(() {
       _searchQuery = query;
     });
   }
 
@@ skipping 33 matching lines @@
     Node title;
     if (_isSearching) {
       title = new Input(focused: true, placeholder: 'Search stocks',
           onChanged: _handleSearchQueryChanged);
     } else {
       title = new Text('Stocks');
     }
 
     var toolbar = new ActionBar(
       children: [
-        new Icon(key: 'menu', style: _iconStyle,
-            size: 24,
-            type: 'navigation/menu_white')
-          ..events.listen('gesturetap', _drawerController.toggle),
+        new EventTarget(
+          new Icon(key: 'menu', style: _iconStyle,
+              size: 24,
+              type: 'navigation/menu_white'),
+          onGestureTap: _drawerController.toggle
+        ),
         new Container(
           style: _titleStyle,
           children: [title]
         ),
-        new Icon(key: 'search', style: _iconStyle,
-            size: 24,
-            type: 'action/search_white')
-          ..events.listen('gesturetap', _handleSearchClick),
-        new Icon(key: 'more_white', style: _iconStyle,
-            size: 24,
-            type: 'navigation/more_vert_white')
-          ..events.listen('gesturetap', _handleMenuClick),
+        new EventTarget(
+          new Icon(key: 'search', style: _iconStyle,
+              size: 24,
+              type: 'action/search_white'),
+          onGestureTap: _handleSearchClick
+        ),
+        new EventTarget(
+          new Icon(key: 'more_white', style: _iconStyle,
+              size: 24,
+              type: 'navigation/more_vert_white'),
+          onGestureTap: _handleMenuClick
+        )
       ]
     );
 
     var list = new Stocklist(stocks: _sortedStocks, query: _searchQuery);
 
     var fab = new FloatingActionButton(content: new Icon(
       type: 'content/add_white', size: 24), level: 3);
 
     var children = [
       new Container(
         key: 'Content',
         style: _style,
         children: [toolbar, list]
       ),
       fab,
       drawer
     ];
 
-    if (_menuController.isOpen) {
-      children.add(new StockMenu(controller: _menuController)
-                   ..events.listen('gesturetap', (_) {
-        // TODO(abarth): We should close the menu when you tap away from the
-        // menu rather than when you tap on the menu.
-        setState(() {
-          _menuController.close();
-        });
-      }));
+    if (_menuController != null) {
+      var menu = new EventTarget(
+        new StockMenu(controller: _menuController),
+        onGestureTap: (_) {
+          // TODO(abarth): We should close the menu when you tap away from the
+          // menu rather than when you tap on the menu.
+          setState(() {
+            _menuController.close();
+            _menuController = null;
+          });
+        }
+      );
+      children.add(menu);
     }
 
     return new Container(key: 'StocksApp', children: children);
   }
 }