Gallery UI tweaks (#4861)

examples/flutter_gallery/lib/demo/shrine/shrine_order.dart

@@ -87,7 +87,10 @@ class OrderItem extends StatelessWidget {
                           items: <int>[0, 1, 2, 3, 4, 5].map((int value) {
                             return new DropDownMenuItem<int>(
                               value: value,
+                              child: new Padding(
+                                padding: const EdgeInsets.only(left: 8.0),
                                 child: new Text('Quantity $value', style: theme.quantityMenuStyle)
+                              )
                             );
                           }).toList(),
                           value: quantity,

examples/flutter_gallery/lib/gallery/home.dart

@@ -48,11 +48,43 @@ class GalleryHome extends StatefulWidget {
 
 class GalleryHomeState extends State<GalleryHome> {
   final Key _homeKey = new ValueKey<String>("Gallery Home");
+  final List<Widget> _listItems = <Widget>[];
 
   @override
-  Widget build(BuildContext context) {
-    final double statusBarHight = (MediaQuery.of(context)?.padding ?? EdgeInsets.zero).top;
+  void initState() {
+    super.initState();
+
+    // The first item in the list just exists to occupy the space behind
+    // the flexible app bar. As it's scrolled out of the way, the app bar's
+    // height will shrink.
+    final double statusBarHeight = (MediaQuery.of(context)?.padding ?? EdgeInsets.zero).top;
+    _listItems.add(new SizedBox(height: _kFlexibleSpaceMaxHeight + statusBarHeight));
 
+    final ThemeData themeData = Theme.of(context);
+    final TextStyle headerStyle = themeData.textTheme.body2.copyWith(color: themeData.primaryColor);
+    String category;
+    for (GalleryItem galleryItem in kAllGalleryItems) {
+      if (category != galleryItem.category) {
+        if (category != null)
+          _listItems.add(new Divider());
+        _listItems.add(
+          new Container(
+            height: 48.0,
+            padding: const EdgeInsets.only(left: 16.0),
+            child: new Align(
+              alignment: FractionalOffset.centerLeft,
+              child: new Text(galleryItem.category, style: headerStyle)
+            )
+          )
+        );
+        category = galleryItem.category;
+      }
+      _listItems.add(galleryItem);
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
     return new Scaffold(
       key: _homeKey,
       drawer: new GalleryDrawer(
@@ -75,27 +107,7 @@ class GalleryHomeState extends State<GalleryHome> {
         )
       ),
       appBarBehavior: AppBarBehavior.under,
-      body: new TwoLevelList(
-        padding: new EdgeInsets.only(top: _kFlexibleSpaceMaxHeight + statusBarHight),
-        type: MaterialListType.oneLine,
-        children: <Widget>[
-          new TwoLevelSublist(
-            leading: new Icon(Icons.star),
-            title: new Text('Demos'),
-            children: _demoItems
-          ),
-          new TwoLevelSublist(
-            leading: new Icon(Icons.extension),
-            title: new Text('Components'),
-            children: _componentItems
-          ),
-          new TwoLevelSublist(
-            leading: new Icon(Icons.color_lens),
-            title: new Text('Style'),
-            children: _styleItems
-          )
-        ]
-      )
+      body: new Block(children: _listItems)
     );
   }
 }

examples/flutter_gallery/lib/gallery/item.dart

@@ -11,7 +11,7 @@ import '../demo/all.dart';
 typedef Widget GalleryDemoBuilder();
 
 class GalleryItem extends StatelessWidget {
-  GalleryItem({ this.title, this.category: 'Components', this.routeName, this.buildRoute }) {
+  GalleryItem({ this.title, this.subtitle, this.category: 'Components', this.routeName, this.buildRoute }) {
     assert(title != null);
     assert(category != null);
     assert(routeName != null);
@@ -19,14 +19,16 @@ class GalleryItem extends StatelessWidget {
   }
 
   final String title;
+  final String subtitle;
   final String category;
   final String routeName;
   final WidgetBuilder buildRoute;
 
   @override
   Widget build(BuildContext context) {
-    return new TwoLevelListItem(
+    return new ListItem(
       title: new Text(title),
+      subtitle: new Text(subtitle),
       onTap: () {
         if (routeName != null) {
           Timeline.instantSync('Start Transition', arguments: <String, String>{
@@ -44,168 +46,193 @@ final List<GalleryItem> kAllGalleryItems = <GalleryItem>[
   // Demos
   new GalleryItem(
     title: 'Pesto',
+    subtitle: 'A simple recipe browser',
     category: 'Demos',
     routeName: PestoDemo.routeName,
     buildRoute: (BuildContext context) => new PestoDemo()
   ),
   new GalleryItem(
     title: 'Shrine',
+    subtitle:'A basic shopping app',
     category: 'Demos',
     routeName: ShrineDemo.routeName,
     buildRoute: (BuildContext context) => new ShrineDemo()
   ),
-  new GalleryItem(
-    title: 'Calculator',
-    category: 'Demos',
-    routeName: CalculatorDemo.routeName,
-    buildRoute: (BuildContext context) => new CalculatorDemo()
-  ),
   new GalleryItem(
     title: 'Contacts',
     category: 'Demos',
+    subtitle: 'Highlights the flexible appbar',
     routeName: ContactsDemo.routeName,
     buildRoute: (BuildContext context) => new ContactsDemo()
   ),
   // Components
   new GalleryItem(
     title: 'Buttons',
+    subtitle: 'All kinds: flat, raised, dropdown, icon, etc',
     routeName: ButtonsDemo.routeName,
     buildRoute: (BuildContext context) => new ButtonsDemo()
   ),
   new GalleryItem(
     title: 'Cards',
+    subtitle: 'Material with rounded corners and a drop shadow',
     routeName: CardsDemo.routeName,
     buildRoute: (BuildContext context) => new CardsDemo()
   ),
   new GalleryItem(
     title: 'Chips',
+    subtitle: 'A label with an optional delete button and avatar',
     routeName: ChipDemo.routeName,
     buildRoute: (BuildContext context) => new ChipDemo()
   ),
   new GalleryItem(
     title: 'Date picker',
+    subtitle: 'Choose month, day, and year',
     routeName: DatePickerDemo.routeName,
     buildRoute: (BuildContext context) => new DatePickerDemo()
   ),
   new GalleryItem(
     title: 'Data tables',
+    subtitle: 'Full-featured grid',
     routeName: DataTableDemo.routeName,
     buildRoute: (BuildContext context) => new DataTableDemo()
   ),
   new GalleryItem(
     title: 'Dialog',
+    subtitle: 'All kinds: simple, alert, fullscreen, etc',
     routeName: DialogDemo.routeName,
     buildRoute: (BuildContext context) => new DialogDemo()
   ),
   new GalleryItem(
     title: 'Expand/collapse list control',
+    subtitle: 'A list with one level of sublists',
     routeName: TwoLevelListDemo.routeName,
     buildRoute: (BuildContext context) => new TwoLevelListDemo()
   ),
   new GalleryItem(
     title: 'Floating action button',
+    subtitle: 'Demos action button transitions',
     routeName: TabsFabDemo.routeName,
     buildRoute: (BuildContext context) => new TabsFabDemo()
   ),
   new GalleryItem(
     title: 'Grid',
+    subtitle: 'Row and column layout',
     routeName: GridListDemo.routeName,
     buildRoute: (BuildContext context) => new GridListDemo()
   ),
   new GalleryItem(
     title: 'Icons',
+    subtitle: 'Enabled and disabled icons with varying opacity',
     routeName: IconsDemo.routeName,
     buildRoute: (BuildContext context) => new IconsDemo()
   ),
   new GalleryItem(
     title: 'Leave-behind list items',
+    subtitle: 'Drag items to expose hidden actions',
     routeName: LeaveBehindDemo.routeName,
     buildRoute: (BuildContext context) => new LeaveBehindDemo()
   ),
   new GalleryItem(
     title: 'List',
+    subtitle: 'All the layout variations for scrollable lists',
     routeName: ListDemo.routeName,
     buildRoute: (BuildContext context) => new ListDemo()
   ),
   new GalleryItem(
     title: 'Menus',
+    subtitle: 'Menu buttons and simple menus',
     routeName: MenuDemo.routeName,
     buildRoute: (BuildContext context) => new MenuDemo()
   ),
   new GalleryItem(
     title: 'Modal bottom sheet',
+    subtitle: 'A modal sheet that slides up from the bottom',
     routeName: ModalBottomSheetDemo.routeName,
     buildRoute: (BuildContext context) => new ModalBottomSheetDemo()
   ),
   new GalleryItem(
     title: 'Over-scroll',
+    subtitle: 'Refresh and overscroll indicators',
     routeName: OverscrollDemo.routeName,
     buildRoute: (BuildContext context) => new OverscrollDemo()
   ),
   new GalleryItem(
     title: 'Page selector',
+    subtitle: 'A pageable list and other widgets',
     routeName: PageSelectorDemo.routeName,
     buildRoute: (BuildContext context) => new PageSelectorDemo()
   ),
   new GalleryItem(
     title: 'Persistent bottom sheet',
+    subtitle: 'A sheet that slides up from the bottom',
     routeName: PersistentBottomSheetDemo.routeName,
     buildRoute: (BuildContext context) => new PersistentBottomSheetDemo()
   ),
   new GalleryItem(
     title: 'Progress indicators',
+    subtitle: 'All kinds: linear, circular, indeterminate, etc',
     routeName: ProgressIndicatorDemo.routeName,
     buildRoute: (BuildContext context) => new ProgressIndicatorDemo()
   ),
   new GalleryItem(
     title: 'Scrollable tabs',
+    subtitle: 'A tab bar that scrolls',
     routeName: ScrollableTabsDemo.routeName,
     buildRoute: (BuildContext context) => new ScrollableTabsDemo()
   ),
   new GalleryItem(
     title: 'Selection controls',
+    subtitle: 'Checkboxes, radio buttons, and switches',
     routeName: SelectionControlsDemo.routeName,
     buildRoute: (BuildContext context) => new SelectionControlsDemo()
   ),
   new GalleryItem(
     title: 'Sliders',
+    subtitle: 'Select a value by dragging the slider thumb',
     routeName: SliderDemo.routeName,
     buildRoute: (BuildContext context) => new SliderDemo()
   ),
   new GalleryItem(
     title: 'Snackbar',
+    subtitle: 'Temporary message that appears at the bottom',
     routeName: SnackBarDemo.routeName,
     buildRoute: (BuildContext context) => new SnackBarDemo()
   ),
   new GalleryItem(
     title: 'Tabs',
+    subtitle: 'Tabs with indepdently scrollable views',
     routeName: TabsDemo.routeName,
     buildRoute: (BuildContext context) => new TabsDemo()
   ),
   new GalleryItem(
     title: 'Text fields',
+    subtitle: 'A Single line of editable text',
     routeName: TextFieldDemo.routeName,
     buildRoute: (BuildContext context) => new TextFieldDemo()
   ),
   new GalleryItem(
     title: 'Time picker',
+    subtitle: 'Choose a hours and minutes',
     routeName: TimePickerDemo.routeName,
     buildRoute: (BuildContext context) => new TimePickerDemo()
   ),
   new GalleryItem(
     title: 'Tooltips',
+    subtitle: 'Display a short message on long-press',
     routeName: TooltipDemo.routeName,
     buildRoute: (BuildContext context) => new TooltipDemo()
   ),
   // Styles
   new GalleryItem(
     title: 'Colors',
+    subtitle: 'All of the predefined colors',
     category: 'Style',
     routeName: ColorsDemo.routeName,
     buildRoute: (BuildContext context) => new ColorsDemo()
   ),
   new GalleryItem(
     title: 'Typography',
+    subtitle: 'All of the predefined text styles',
     category: 'Style',
     routeName: TypographyDemo.routeName,
     buildRoute: (BuildContext context) => new TypographyDemo()

examples/flutter_gallery/test/smoke_test.dart

@@ -74,14 +74,6 @@ void main() {
     await tester.pump(); // see https://github.com/flutter/flutter/issues/1865
     await tester.pump(); // triggers a frame
 
-    // Expand the demo category submenus.
-    for (String category in demoCategories.reversed) {
-      await tester.tap(find.text(category));
-      await tester.pump();
-      await tester.pump(
-          const Duration(seconds: 1)); // Wait until the menu has expanded.
-    }
-
     final List<double> scrollDeltas = new List<double>();
     double previousY = tester.getTopRight(find.text(demoCategories[0])).y;
     for (String routeName in routeNames) {
@@ -94,8 +86,7 @@ void main() {
     for (int i = 0; i < routeNames.length; i += 1) {
       final String routeName = routeNames[i];
       await smokeDemo(tester, routeName);
-      await tester.scroll(findGalleryItemByRouteName(tester, routeName),
-          new Offset(0.0, scrollDeltas[i]));
+      await tester.scroll(findGalleryItemByRouteName(tester, routeName), new Offset(0.0, scrollDeltas[i]));
       await tester.pump();
     }
 

examples/flutter_gallery/test_driver/transitions_perf_test.dart

@@ -25,7 +25,6 @@ final List<String> demoTitles = <String>[
   // Demos
   // 'Pesto', TODO(hansmuller): restore when Pesto has a back button.
   'Shrine',
-  'Calculator',
   'Contacts',
   // Components
   'Buttons',