Initial implementation of SnackBar

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/widgets/basic.dart';
 import 'package:sky/widgets/drawer.dart';
 import 'package:sky/widgets/drawer_header.dart';
 import 'package:sky/widgets/floating_action_button.dart';
 import 'package:sky/widgets/icon.dart';
 import 'package:sky/widgets/icon_button.dart';
 import 'package:sky/widgets/menu_divider.dart';
 import 'package:sky/widgets/menu_item.dart';
 import 'package:sky/widgets/modal_overlay.dart';
 import 'package:sky/widgets/navigator.dart';
 import 'package:sky/widgets/popup_menu.dart';
 import 'package:sky/widgets/radio.dart';
+import 'package:sky/widgets/snack_bar.dart';
 import 'package:sky/widgets/scaffold.dart';
 import 'package:sky/widgets/tabs.dart';
 import 'package:sky/widgets/theme.dart';
 import 'package:sky/widgets/tool_bar.dart';
 import 'package:sky/widgets/widget.dart';
 
 import 'stock_data.dart';
 import 'stock_list.dart';
 import 'stock_menu.dart';
 import 'stock_types.dart';
@@ skipping 16 matching lines @@
   void syncFields(StockHome source) {
     navigator = source.navigator;
     stocks = source.stocks;
     stockMode = source.stockMode;
     modeUpdater = source.modeUpdater;
   }
 
   bool _isSearching = false;
   String _searchQuery;
 
+  bool _isShowingSnackBar = false;
+
   void _handleSearchBegin() {
     setState(() {
       _isSearching = true;
     });
   }
 
   void _handleSearchEnd() {
     setState(() {
       _isSearching = false;
       _searchQuery = null;
@@ skipping 152 matching lines @@
         icon: 'navigation/arrow_back_grey600',
         onPressed: _handleSearchEnd),
       center: new Input(
         focused: true,
         placeholder: 'Search stocks',
         onChanged: _handleSearchQueryChanged),
       backgroundColor: Theme.of(this).canvasColor
     );
   }
 
+  void _handleUndo() {
+    setState(() {
+      _isShowingSnackBar = false;
+    });
+  }
+
+  Widget buildSnackBar() {
+    if (!_isShowingSnackBar)
+      return null;
+    return new SnackBar(
+      content: new Text("Stock purchased!"),
+      actions: [new SnackBarAction(label: "UNDO", onPressed: _handleUndo)]
+    );
+  }
+
+  void _handleStockPurchased() {
+    setState(() {
+      _isShowingSnackBar = true;
+    });
+  }
+
+  Widget buildFloatingActionButton() {
+    return new FloatingActionButton(
+      child: new Icon(type: 'content/add_white', size: 24),
+      onPressed: _handleStockPurchased
+    );
+  }
+
   void addMenuToOverlays(List<Widget> overlays) {
     if (_menuController == null)
       return;
     overlays.add(new ModalOverlay(
       children: [new StockMenu(
         controller: _menuController,
         autorefresh: _autorefresh,
         onAutorefreshChanged: _handleAutorefreshChanged
       )],
       onDismiss: _handleMenuHide));
   }
 
   Widget build() {
     List<Widget> overlays = [
       new Scaffold(
         toolbar: _isSearching ? buildSearchBar() : buildToolBar(),
         body: buildTabNavigator(),
-        floatingActionButton: new FloatingActionButton(
-          child: new Icon(type: 'content/add_white', size: 24)
-        ),
+        snackBar: buildSnackBar(),
+        floatingActionButton: buildFloatingActionButton(),
         drawer: _drawerShowing ? buildDrawer() : null
       ),
     ];
     addMenuToOverlays(overlays);
     return new Stack(overlays);
   }
 }