AnimatedContainer: generalized Container widget that handles animating values

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 'package:vector_math/vector_math.dart';
+
 import 'stock_data.dart';
 import 'stock_list.dart';
 import 'stock_menu.dart';
 import 'stock_types.dart';
 
 typedef void ModeUpdater(StockMode mode);
 
 class StockHome extends StatefulComponent {
 
   StockHome(this.navigator, this.stocks, this.stockMode, this.modeUpdater) {
@@ skipping 213 matching lines @@
 
   void _handleUndo() {
     setState(() {
       _isShowingSnackBar = false;
     });
   }
 
   Widget buildSnackBar() {
     if (!_isShowingSnackBar)
       return null;
-    return new SnackBar(
+    Matrix4 transform = new Matrix4.identity();

[Matt Perry, 2015/07/08 20:42:13]

Ignore this. I want to use an AnimatedContainer here eventually, but the
Transform here seems to break hit-testing.

[abarth-chromium, 2015/07/08 21:02:04]

Does that mean you're going to remove this part of the diff before landing?

[Matt Perry, 2015/07/08 21:41:03]

Yep.

+    transform.translate(0.0, -300.0);
+    return new Transform(
+                         transform: transform,
+                         child:
+                         new SnackBar(
       content: new Text("Stock purchased!"),
       actions: [new SnackBarAction(label: "UNDO", onPressed: _handleUndo)]
-    );
+    )
+                        );
   }
 
   void _handleStockPurchased() {
     setState(() {
       _isShowingSnackBar = true;
     });
   }
 
   Widget buildFloatingActionButton() {
     return new FloatingActionButton(
@@ skipping 21 matching lines @@
         body: buildTabNavigator(),
         snackBar: buildSnackBar(),
         floatingActionButton: buildFloatingActionButton(),
         drawer: _drawerShowing ? buildDrawer() : null
       ),
     ];
     addMenuToOverlays(overlays);
     return new Stack(overlays);
   }
 }