Heroes

examples/stocks/lib/stock_home.dart

@@ -186,14 +186,16 @@ class StockHomeState extends State<StockHome> {
   Widget buildStockList(BuildContext context, Iterable<Stock> stocks) {
     return new StockList(
       stocks: stocks.toList(),
-      onAction: (Stock stock, GlobalKey arrowKey) {
+      onAction: (Stock stock, Key arrowKey) {
         setState(() {
           stock.percentChange = 100.0 * (1.0 / stock.lastSale);
           stock.lastSale += 1.0;
         });
       },
-      onOpen: (Stock stock, GlobalKey arrowKey) {
-        config.navigator.pushNamed('/stock/${stock.symbol}');
+      onOpen: (Stock stock, Key arrowKey) {
+        Set<Key> mostValuableKeys = new Set<Key>();
+        mostValuableKeys.add(arrowKey);
+        config.navigator.pushNamed('/stock/${stock.symbol}', mostValuableKeys: mostValuableKeys);
       }
     );
   }

examples/stocks/lib/stock_row.dart

@@ -6,7 +6,7 @@ part of stocks;
 
 enum StockRowPartKind { arrow }
 
-class StockRowPartKey extends GlobalKey {
+class StockRowPartKey extends Key {
   const StockRowPartKey(this.stock, this.part) : super.constructor();
   final Stock stock;
   final StockRowPartKind part;
@@ -21,7 +21,7 @@ class StockRowPartKey extends GlobalKey {
   String toString() => '[StockRowPartKey ${stock.symbol}:${part.toString().split(".")[1]})]';
 }
 
-typedef void StockRowActionCallback(Stock stock, GlobalKey arrowKey);
+typedef void StockRowActionCallback(Stock stock, Key arrowKey);
 
 class StockRow extends StatelessComponent {
   StockRow({
@@ -30,7 +30,7 @@ class StockRow extends StatelessComponent {
     this.onLongPressed
   }) : this.stock = stock,
        _arrowKey = new StockRowPartKey(stock, StockRowPartKind.arrow),
-       super(key: new GlobalObjectKey(stock));
+       super(key: new ObjectKey(stock));
 
   final Stock stock;
   final StockRowActionCallback onPressed;
@@ -53,7 +53,7 @@ class StockRow extends StatelessComponent {
   }
 
   Widget build(BuildContext context) {
-    String lastSale = "\$${stock.lastSale.toStringAsFixed(2)}";
+    final String lastSale = "\$${stock.lastSale.toStringAsFixed(2)}";
     String changeInPrice = "${stock.percentChange.toStringAsFixed(2)}%";
     if (stock.percentChange > 0)
       changeInPrice = "+" + changeInPrice;
@@ -69,9 +69,12 @@ class StockRow extends StatelessComponent {
         ),
         child: new Row(<Widget>[
             new Container(
-              key: _arrowKey,
-              child: new StockArrow(percentChange: stock.percentChange),
-              margin: const EdgeDims.only(right: 5.0)
+              margin: const EdgeDims.only(right: 5.0),
+              child: new Hero(
+                tag: StockRowPartKind.arrow,
+                key: _arrowKey,
+                child: new StockArrow(percentChange: stock.percentChange)
+              )
             ),
             new Flexible(
               child: new Row(<Widget>[

examples/stocks/lib/stock_symbol_viewer.dart

@@ -36,7 +36,11 @@ class StockSymbolViewer extends StatelessComponent {
                         '${stock.symbol}',
                         style: Theme.of(context).text.display2
                       ),
-                      new StockArrow(percentChange: stock.percentChange)
+                      new Hero(
+                        tag: StockRowPartKind.arrow,
+                        turns: 2,
+                        child: new StockArrow(percentChange: stock.percentChange)
+                      ),
                     ],
                     justifyContent: FlexJustifyContent.spaceBetween
                   ),
@@ -51,7 +55,8 @@ class StockSymbolViewer extends StatelessComponent {
               )
             )
           )
-      ])
+        ]
+      )
     );
   }
 

packages/flutter/lib/widgets.dart

@@ -16,6 +16,7 @@ export 'src/widgets/focus.dart';
 export 'src/widgets/framework.dart';
 export 'src/widgets/gesture_detector.dart';
 export 'src/widgets/gridpaper.dart';
+export 'src/widgets/heroes.dart';
 export 'src/widgets/homogeneous_viewport.dart';
 export 'src/widgets/mimic.dart';
 export 'src/widgets/mixed_viewport.dart';