bottomsheet fix

Runtime/material/scaffold.cs

                 this._snackBarController = SnackBar.createAnimationController(vsync: this);
                 this._snackBarController.addStatusListener(this._handleSnackBarStatusChange);
             }
-            
+
             if (this._snackBars.isEmpty()) {
                 D.assert(this._snackBarController.isDismissed);
                 this._snackBarController.forward();
                 this._currentBottomSheet = this._buildBottomSheet<object>(
                     (BuildContext context) => this.widget.bottomSheet,
                     controller,
-                    false);
+                    false,
+                    null);
             }
         }
 
 
 
         PersistentBottomSheetController<T> _buildBottomSheet<T>(WidgetBuilder builder, AnimationController controller,
-            bool isLocalHistoryEntry) {
+            bool isLocalHistoryEntry, T resolveValue) {
             Promise<T> completer = new Promise<T>();
             GlobalKey<_PersistentBottomSheetState> bottomSheetKey = GlobalKey<_PersistentBottomSheetState>.key();
             _PersistentBottomSheet bottomSheet = null;
                 }
 
                 this.setState(() => { this._currentBottomSheet = null; });
-                completer.Done();
+                completer.Resolve(resolveValue);
             }
 
             LocalHistoryEntry entry = isLocalHistoryEntry
                 isLocalHistoryEntry);
         }
 
-        PersistentBottomSheetController<object> showBottomSheet(WidgetBuilder builder) {
+        public PersistentBottomSheetController<object> showBottomSheet(WidgetBuilder builder) {
-                this._currentBottomSheet = this._buildBottomSheet<object>(builder, controller, true);
+                this._currentBottomSheet = this._buildBottomSheet<object>(builder, controller, true, null);
             });
             return this._currentBottomSheet;
         }
 
         public readonly Promise<U> _completer;
 
-        IPromise<U> closed {
+        public IPromise<U> closed {
             get { return this._completer; }
         }
 
     }
 
 
-    class _PersistentBottomSheet : StatefulWidget {
+    public class _PersistentBottomSheet : StatefulWidget {
         public _PersistentBottomSheet(
             Key key = null,
             AnimationController animationController = null,
     }
 
 
-    class PersistentBottomSheetController<T> : ScaffoldFeatureController<_PersistentBottomSheet, T> {
+    public class PersistentBottomSheetController<T> : ScaffoldFeatureController<_PersistentBottomSheet, T> {
         public PersistentBottomSheetController(
             _PersistentBottomSheet widget,
             Promise<T> completer,

Samples/UIWidgetSample/MaterialSample.cs

     class MaterialAppBarWidgetState : State<MaterialAppBarWidget> {
         Choice _selectedChoice = Choice.choices[0];
 
+        GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>.key();
+
+        VoidCallback _showBottomSheetCallback;
+
+        public override void initState() {
+            base.initState();
+            this._showBottomSheetCallback = this._showBottomSheet;
+        }
+
+        void _showBottomSheet() {
+            this.setState(() => { this._showBottomSheetCallback = null; });
+
+            this._scaffoldKey.currentState.showBottomSheet((BuildContext subContext) => {
+                ThemeData themeData = Theme.of(subContext);
+                return new Container(
+                    decoration: new BoxDecoration(
+                        border: new Border(
+                            top: new BorderSide(
+                                color: themeData.disabledColor))),
+                    child: new Padding(
+                        padding: EdgeInsets.all(8.0f),
+                        child: new Text("Alert Bottom Sheet",
+                            textAlign: TextAlign.center,
+                            style: new TextStyle(
+                                color: themeData.accentColor,
+                                fontSize: 24.0f))
+                    )
+                );
+            }).closed.Then((object obj) => {
+                if (this.mounted) {
+                    this.setState(() => { this._showBottomSheetCallback = this._showBottomSheet; });
+                }
+
+                return null;
+            });
+        }
+
         void _select(Choice choice) {
             this.setState(() => { this._selectedChoice = choice; });
         }
+                key: this._scaffoldKey,
                 appBar: new AppBar(
                     title: new Text("Basic AppBar"),
                     actions: new List<Widget> {
                     padding: EdgeInsets.all(16.0f),
                     child: new ChoiceCard(choice: this._selectedChoice)
                 ),
-                floatingActionButton: new Builder(
-                    builder: (BuildContext subContext) => {
-                        return new FloatingActionButton(
-                            child: new Icon(Unity.UIWidgets.material.Icons.add_alert),
-                            onPressed: () => {
-                                Scaffold.of(subContext).showSnackBar(new SnackBar(
-                                    content: new Text("Float Alerting !")));
-                            });
-                    }),
+                floatingActionButton: new FloatingActionButton(
+                    backgroundColor: Colors.redAccent,
+                    child: new Icon(Unity.UIWidgets.material.Icons.add_alert),
+                    onPressed: this._showBottomSheetCallback
+                ),
                 drawer: new Drawer(
                     child: new ListView(
                         padding: EdgeInsets.zero,
                         }
                     )
                 )
-                
             );
         }
     }