Merge pull request #3081 from HansMuller/gallery_tweaks

Gallery Tweaks

examples/material_gallery/lib/demo/modal_bottom_sheet_demo.dart

@@ -16,11 +16,8 @@ class ModalBottomSheetDemo extends StatelessWidget {
     return new Scaffold(
       appBar: new AppBar(title: new Text("Modal Bottom Sheet")),
       body: new Center(
-        child: new Container(
-          width: 200.0,
-          height: 200.0,
         child: new RaisedButton(
-            child: new Text('Show the modal bottom sheet', style: textStyle),
+          child: new Text('SHOW BOTTOM SHEET'),
           onPressed: () {
             showModalBottomSheet/*<Null>*/(context: context, builder: (BuildContext context) {
               return new Container(
@@ -33,7 +30,6 @@ class ModalBottomSheetDemo extends StatelessWidget {
           }
         )
       )
-      )
     );
   }
 }

examples/material_gallery/lib/demo/persistent_bottom_sheet_demo.dart

@@ -4,7 +4,13 @@
 
 import 'package:flutter/material.dart';
 
-class PersistentBottomSheetDemo extends StatelessWidget {
+class PersistentBottomSheetDemo extends StatefulWidget {
+  @override
+  _PersistentBottomSheetDemoState createState() => new _PersistentBottomSheetDemoState();
+}
+
+class _PersistentBottomSheetDemoState extends State<PersistentBottomSheetDemo> {
+  final GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>();
 
   final TextStyle textStyle = new TextStyle(
     color: Colors.indigo[400],
@@ -12,8 +18,20 @@ class PersistentBottomSheetDemo extends StatelessWidget {
     textAlign: TextAlign.center
   );
 
-  void showBottomSheet(BuildContext context) {
-    Scaffold.of(context).showBottomSheet((_) {
+  VoidCallback _showBottomSheetCallback;
+
+  @override
+  void initState() {
+    super.initState();
+    _showBottomSheetCallback = showBottomSheet;
+  }
+
+
+  void showBottomSheet() {
+    setState(() { // disable the button
+      _showBottomSheetCallback = null;
+    });
+    _scaffoldKey.currentState.showBottomSheet/*<Null>*/((BuildContext context) {
       return new Container(
         decoration: new BoxDecoration(
           border: new Border(top: new BorderSide(color: Colors.black26))
@@ -23,31 +41,29 @@ class PersistentBottomSheetDemo extends StatelessWidget {
           child: new Text("This is a Material persistent bottom sheet. Drag downwards to dismiss it.", style: textStyle)
         )
       );
+    })
+    .closed.then((_) {
+      setState(() { // re-enable the button
+        _showBottomSheetCallback = showBottomSheet;
+      });
     });
   }
 
   @override
-  Widget build(BuildContext notUsed) { // Can't find the Scaffold from this context.
+  Widget build(BuildContext context) {
     return new Scaffold(
+      key: _scaffoldKey,
       appBar: new AppBar(title: new Text("Persistent Bottom Sheet")),
       floatingActionButton: new FloatingActionButton(
         child: new Icon(icon: Icons.add),
         backgroundColor: Colors.redAccent[200]
       ),
-      body: new Builder(
-        builder: (BuildContext context) {
-          return new Center(
-            child: new Container(
-              width: 200.0,
-              height: 200.0,
+      body: new Center(
         child: new RaisedButton(
-                onPressed: () { showBottomSheet(context); },
-                child: new Text('Show the persistent bottom sheet', style: textStyle)
+          onPressed: _showBottomSheetCallback,
+          child: new Text('SHOW BOTTOM SHEET')
         )
       )
     );
   }
-      )
-    );
-  }
 }

examples/material_gallery/lib/demo/snack_bar_demo.dart

@@ -17,9 +17,16 @@ const String _text2 =
 const String _text3 =
   "By default snackbars automatically disappear after a few seconds ";
 
-class SnackBarDemo extends StatelessWidget {
+class SnackBarDemo extends StatefulWidget {
   SnackBarDemo({ Key key }) : super(key: key);
 
+  @override
+  _SnackBarDemoState createState() => new _SnackBarDemoState();
+}
+
+class _SnackBarDemoState extends State<SnackBarDemo> {
+  int _snackBarIndex = 1;
+
   Widget buildBody(BuildContext context) {
     return new Padding(
       padding: const EdgeInsets.all(24.0),
@@ -27,21 +34,24 @@ class SnackBarDemo extends StatelessWidget {
         children: <Widget>[
           new Text(_text1),
           new Text(_text2),
-          new RaisedButton(
-            child: new Text('Show a SnackBar'),
+          new Center(
+            child: new RaisedButton(
+              child: new Text('SHOW A SNACKBAR'),
               onPressed: () {
+                final int thisSnackBarIndex = _snackBarIndex++;
                 Scaffold.of(context).showSnackBar(new SnackBar(
-                content: new Text('This is a SnackBar'),
+                  content: new Text('This is SnackBar #$thisSnackBarIndex'),
                   action: new SnackBarAction(
                     label: 'ACTION',
                     onPressed: () {
                       Scaffold.of(context).showSnackBar(new SnackBar(
-                      content: new Text("You pressed the SnackBar's Action")
+                        content: new Text("You pressed SnackBar $thisSnackBarIndex's Action")
                       ));
                     }
                   )
                 ));
               }
+            )
           ),
           new Text(_text3),
         ]