Dart 3.9 / Flutter 3.35 [first LLM release] (#2714)

I got carried away with Gemini and basically rewrote CI and the release
process for the new LLM reality. This work was largely completed by
Gemini.

- Bump all SDK versions to the current beta (3.9.0-0)
- Run `flutter channel beta`
- Wrote `ci_script.dart` to replace the bash scripts
- Converted repository to pub workspace #2499 
- Added llm.md and release.md
- Added redirect for deprecated Samples Index

## Pre-launch Checklist

- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I have added sample code updates to the [changelog].
- [x] I updated/added relevant documentation (doc comments with `///`).

material_3_demo/lib/main.dart

@@ -75,20 +75,19 @@ class _AppState extends State<App> {
       theme: ThemeData(
         colorSchemeSeed:
             _colorSelectionMethod == ColorSelectionMethod.colorSeed
-                ? _colorSelected.color
-                : null,
-        colorScheme:
-            _colorSelectionMethod == ColorSelectionMethod.image
-                ? _imageColorScheme
-                : null,
+            ? _colorSelected.color
+            : null,
+        colorScheme: _colorSelectionMethod == ColorSelectionMethod.image
+            ? _imageColorScheme
+            : null,
         useMaterial3: _useMaterial3,
         brightness: Brightness.light,
       ),
       darkTheme: ThemeData(
         colorSchemeSeed:
             _colorSelectionMethod == ColorSelectionMethod.colorSeed
-                ? _colorSelected.color
-                : _imageColorScheme!.primary,
+            ? _colorSelected.color
+            : _imageColorScheme!.primary,
         useMaterial3: _useMaterial3,
         brightness: Brightness.dark,
       ),

material_3_demo/lib/src/animations.dart

@@ -8,7 +8,11 @@ class SizeAnimation extends CurvedAnimation {
   SizeAnimation(Animation<double> parent)
     : super(
         parent: parent,
-        curve: const Interval(0.2, 0.8, curve: Curves.easeInOutCubicEmphasized),
+        curve: const Interval(
+          0.2,
+          0.8,
+          curve: Curves.easeInOutCubicEmphasized,
+        ),
         reverseCurve: Interval(
           0,
           0.2,
@@ -21,7 +25,11 @@ class OffsetAnimation extends CurvedAnimation {
   OffsetAnimation(Animation<double> parent)
     : super(
         parent: parent,
-        curve: const Interval(0.4, 1.0, curve: Curves.easeInOutCubicEmphasized),
+        curve: const Interval(
+          0.4,
+          1.0,
+          curve: Curves.easeInOutCubicEmphasized,
+        ),
         reverseCurve: Interval(
           0,
           0.2,

material_3_demo/lib/src/buttons.dart

@@ -23,10 +23,9 @@ class BrightnessButton extends StatelessWidget {
       preferBelow: showTooltipBelow,
       message: 'Toggle brightness',
       child: IconButton(
-        icon:
-            isBright
-                ? const Icon(Icons.dark_mode_outlined)
-                : const Icon(Icons.light_mode_outlined),
+        icon: isBright
+            ? const Icon(Icons.dark_mode_outlined)
+            : const Icon(Icons.light_mode_outlined),
         onPressed: () => handleBrightnessChange(!isBright),
       ),
     );
@@ -50,10 +49,9 @@ class Material3Button extends StatelessWidget {
       preferBelow: showTooltipBelow,
       message: 'Switch to Material ${useMaterial3 ? 2 : 3}',
       child: IconButton(
-        icon:
-            useMaterial3
-                ? const Icon(Icons.filter_2)
-                : const Icon(Icons.filter_3),
+        icon: useMaterial3
+            ? const Icon(Icons.filter_2)
+            : const Icon(Icons.filter_3),
         onPressed: handleMaterialVersionChange,
       ),
     );
@@ -77,7 +75,9 @@ class ColorSeedButton extends StatelessWidget {
     return PopupMenuButton(
       icon: const Icon(Icons.palette_outlined),
       tooltip: 'Select a seed color',
-      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
+      shape: RoundedRectangleBorder(
+        borderRadius: BorderRadius.circular(10),
+      ),
       itemBuilder: (context) {
         return List.generate(ColorSeed.values.length, (index) {
           ColorSeed currentColor = ColorSeed.values[index];
@@ -130,7 +130,9 @@ class ColorImageButton extends StatelessWidget {
     return PopupMenuButton(
       icon: const Icon(Icons.image_outlined),
       tooltip: 'Select a color extraction image',
-      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
+      shape: RoundedRectangleBorder(
+        borderRadius: BorderRadius.circular(10),
+      ),
       itemBuilder: (context) {
         return List.generate(ColorImageProvider.values.length, (index) {
           final currentImageProvider = ColorImageProvider.values[index];

material_3_demo/lib/src/color_box.dart

@@ -77,7 +77,9 @@ class _ColorBoxState extends State<ColorBox> {
                       await Clipboard.setData(data);
                       messenger.hideCurrentSnackBar();
                       messenger.showSnackBar(
-                        SnackBar(content: Text('Copied $hex to clipboard')),
+                        SnackBar(
+                          content: Text('Copied $hex to clipboard'),
+                        ),
                       );
                     },
                   ),

material_3_demo/lib/src/color_palettes_screen.dart

@@ -61,16 +61,15 @@ class ColorPalettesScreen extends StatelessWidget {
           TextSpan(
             text: 'dynamic_color',
             style: const TextStyle(decoration: TextDecoration.underline),
-            recognizer:
-                TapGestureRecognizer()
-                  ..onTap = () async {
-                    final url = Uri.parse(
-                      'https://pub.dev/packages/dynamic_color',
-                    );
-                    if (!await launchUrl(url)) {
-                      throw Exception('Could not launch $url');
-                    }
-                  },
+            recognizer: TapGestureRecognizer()
+              ..onTap = () async {
+                final url = Uri.parse(
+                  'https://pub.dev/packages/dynamic_color',
+                );
+                if (!await launchUrl(url)) {
+                  throw Exception('Could not launch $url');
+                }
+              },
           ),
           const TextSpan(text: ' package.'),
         ],
@@ -454,7 +453,9 @@ class ColorChip extends StatelessWidget {
         padding: const EdgeInsets.all(16),
         child: Row(
           children: [
-            Expanded(child: Text(label, style: TextStyle(color: labelColor))),
+            Expanded(
+              child: Text(label, style: TextStyle(color: labelColor)),
+            ),
           ],
         ),
       ),

material_3_demo/lib/src/component_screen.dart

@@ -49,10 +49,9 @@ class FirstComponentList extends StatelessWidget {
       child: CustomScrollView(
         slivers: [
           SliverPadding(
-            padding:
-                showSecondList
-                    ? const EdgeInsetsDirectional.only(end: smallSpacing)
-                    : EdgeInsets.zero,
+            padding: showSecondList
+                ? const EdgeInsetsDirectional.only(end: smallSpacing)
+                : EdgeInsets.zero,
             sliver: SliverList(
               delegate: BuildSlivers(
                 heights: heights,
@@ -123,7 +122,11 @@ class SecondComponentList extends StatelessWidget {
 // as the contents of the list are exposed for the first time, and
 // then remain fixed.
 class _CacheHeight extends SingleChildRenderObjectWidget {
-  const _CacheHeight({super.child, required this.heights, required this.index});
+  const _CacheHeight({
+    super.child,
+    required this.heights,
+    required this.index,
+  });
 
   final List<double?> heights;
   final int index;
@@ -537,7 +540,9 @@ class Cards extends StatelessWidget {
             child: Card(
               elevation: 0,
               shape: RoundedRectangleBorder(
-                side: BorderSide(color: Theme.of(context).colorScheme.outline),
+                side: BorderSide(
+                  color: Theme.of(context).colorScheme.outline,
+                ),
                 borderRadius: const BorderRadius.all(Radius.circular(12)),
               ),
               child: Container(
@@ -626,7 +631,9 @@ class _TextFieldsState extends State<TextFields> {
                       controller: _controllerFilled,
                       decoration: InputDecoration(
                         prefixIcon: const Icon(Icons.search),
-                        suffixIcon: _ClearButton(controller: _controllerFilled),
+                        suffixIcon: _ClearButton(
+                          controller: _controllerFilled,
+                        ),
                         labelText: 'Filled',
                         hintText: 'hint text',
                         helperText: 'supporting text',
@@ -645,7 +652,9 @@ class _TextFieldsState extends State<TextFields> {
                       enabled: false,
                       decoration: InputDecoration(
                         prefixIcon: const Icon(Icons.search),
-                        suffixIcon: _ClearButton(controller: _controllerFilled),
+                        suffixIcon: _ClearButton(
+                          controller: _controllerFilled,
+                        ),
                         labelText: 'Disabled',
                         hintText: 'hint text',
                         helperText: 'supporting text',
@@ -737,51 +746,49 @@ class _DialogsState extends State<Dialogs> {
   void openDialog(BuildContext context) {
     showDialog<void>(
       context: context,
-      builder:
-          (context) => AlertDialog(
-            title: const Text('What is a dialog?'),
-            content: const Text(
-              'A dialog is a type of modal window that appears in front of app content to provide critical information, or prompt for a decision to be made.',
-            ),
-            actions: <Widget>[
-              TextButton(
-                child: const Text('Dismiss'),
-                onPressed: () => Navigator.of(context).pop(),
-              ),
-              FilledButton(
-                child: const Text('Okay'),
-                onPressed: () => Navigator.of(context).pop(),
-              ),
-            ],
+      builder: (context) => AlertDialog(
+        title: const Text('What is a dialog?'),
+        content: const Text(
+          'A dialog is a type of modal window that appears in front of app content to provide critical information, or prompt for a decision to be made.',
+        ),
+        actions: <Widget>[
+          TextButton(
+            child: const Text('Dismiss'),
+            onPressed: () => Navigator.of(context).pop(),
           ),
+          FilledButton(
+            child: const Text('Okay'),
+            onPressed: () => Navigator.of(context).pop(),
+          ),
+        ],
+      ),
     );
   }
 
   void openFullscreenDialog(BuildContext context) {
     showDialog<void>(
       context: context,
-      builder:
-          (context) => Dialog.fullscreen(
-            child: Padding(
-              padding: const EdgeInsets.all(20.0),
-              child: Scaffold(
-                appBar: AppBar(
-                  title: const Text('Full-screen dialog'),
-                  centerTitle: false,
-                  leading: IconButton(
-                    icon: const Icon(Icons.close),
-                    onPressed: () => Navigator.of(context).pop(),
-                  ),
-                  actions: [
-                    TextButton(
-                      child: const Text('Close'),
-                      onPressed: () => Navigator.of(context).pop(),
-                    ),
-                  ],
-                ),
+      builder: (context) => Dialog.fullscreen(
+        child: Padding(
+          padding: const EdgeInsets.all(20.0),
+          child: Scaffold(
+            appBar: AppBar(
+              title: const Text('Full-screen dialog'),
+              centerTitle: false,
+              leading: IconButton(
+                icon: const Icon(Icons.close),
+                onPressed: () => Navigator.of(context).pop(),
               ),
+              actions: [
+                TextButton(
+                  child: const Text('Close'),
+                  onPressed: () => Navigator.of(context).pop(),
+                ),
+              ],
             ),
           ),
+        ),
+      ),
     );
   }
 
@@ -874,26 +881,24 @@ class _SwitchRowState extends State<SwitchRow> {
         // TODO: use SwitchListTile when thumbIcon is available https://github.com/flutter/flutter/issues/118616
         Switch(
           value: value0,
-          onChanged:
-              widget.isEnabled
-                  ? (value) {
-                    setState(() {
-                      value0 = value;
-                    });
-                  }
-                  : null,
+          onChanged: widget.isEnabled
+              ? (value) {
+                  setState(() {
+                    value0 = value;
+                  });
+                }
+              : null,
         ),
         Switch(
           thumbIcon: thumbIcon,
           value: value1,
-          onChanged:
-              widget.isEnabled
-                  ? (value) {
-                    setState(() {
-                      value1 = value;
-                    });
-                  }
-                  : null,
+          onChanged: widget.isEnabled
+              ? (value) {
+                  setState(() {
+                    value1 = value;
+                  });
+                }
+              : null,
         ),
       ],
     );
@@ -1132,7 +1137,10 @@ List<Widget> barWithBadgeDestinations = [
   ),
   NavigationDestination(
     tooltip: '',
-    icon: Badge.count(count: 3, child: const Icon(Icons.videocam_outlined)),
+    icon: Badge.count(
+      count: 3,
+      child: const Icon(Icons.videocam_outlined),
+    ),
     label: 'Meet',
     selectedIcon: Badge.count(count: 3, child: const Icon(Icons.videocam)),
   ),
@@ -1186,12 +1194,11 @@ class _NavigationBarsState extends State<NavigationBars> {
           });
           if (!widget.isExampleBar) widget.onSelectItem!(index);
         },
-        destinations:
-            widget.isExampleBar && widget.isBadgeExample
-                ? barWithBadgeDestinations
-                : widget.isExampleBar
-                ? exampleBarDestinations
-                : appBarDestinations,
+        destinations: widget.isExampleBar && widget.isBadgeExample
+            ? barWithBadgeDestinations
+            : widget.isExampleBar
+            ? exampleBarDestinations
+            : appBarDestinations,
       ),
     );
 
@@ -1369,7 +1376,10 @@ class _ChipsState extends State<Chips> {
                 onPressed: () {},
                 onDeleted: () {},
               ),
-              ActionChip(label: const Text('Suggestion'), onPressed: () {}),
+              ActionChip(
+                label: const Text('Suggestion'),
+                onPressed: () {},
+              ),
             ],
           ),
           colDivider,
@@ -1645,9 +1655,18 @@ class _BottomSheetSectionState extends State<BottomSheetSection> {
       IconButton(onPressed: () {}, icon: const Icon(Icons.share_outlined)),
       IconButton(onPressed: () {}, icon: const Icon(Icons.add)),
       IconButton(onPressed: () {}, icon: const Icon(Icons.delete_outline)),
-      IconButton(onPressed: () {}, icon: const Icon(Icons.archive_outlined)),
-      IconButton(onPressed: () {}, icon: const Icon(Icons.settings_outlined)),
-      IconButton(onPressed: () {}, icon: const Icon(Icons.favorite_border)),
+      IconButton(
+        onPressed: () {},
+        icon: const Icon(Icons.archive_outlined),
+      ),
+      IconButton(
+        onPressed: () {},
+        icon: const Icon(Icons.settings_outlined),
+      ),
+      IconButton(
+        onPressed: () {},
+        icon: const Icon(Icons.favorite_border),
+      ),
     ];
     List<Text> labelList = const <Text>[
       Text('Share'),
@@ -1690,7 +1709,9 @@ class _BottomSheetSectionState extends State<BottomSheetSection> {
                   return SizedBox(
                     height: 150,
                     child: Padding(
-                      padding: const EdgeInsets.symmetric(horizontal: 32.0),
+                      padding: const EdgeInsets.symmetric(
+                        horizontal: 32.0,
+                      ),
                       child: ListView(
                         shrinkWrap: true,
                         scrollDirection: Axis.horizontal,
@@ -1731,7 +1752,9 @@ class _BottomSheetSectionState extends State<BottomSheetSection> {
                   return SizedBox(
                     height: 150,
                     child: Padding(
-                      padding: const EdgeInsets.symmetric(horizontal: 32.0),
+                      padding: const EdgeInsets.symmetric(
+                        horizontal: 32.0,
+                      ),
                       child: ListView(
                         shrinkWrap: true,
                         scrollDirection: Axis.horizontal,
@@ -1817,9 +1840,18 @@ class IconButtonAnchorExample extends StatelessWidget {
         MenuItemButton(child: const Text('Menu 2'), onPressed: () {}),
         SubmenuButton(
           menuChildren: <Widget>[
-            MenuItemButton(onPressed: () {}, child: const Text('Menu 3.1')),
-            MenuItemButton(onPressed: () {}, child: const Text('Menu 3.2')),
-            MenuItemButton(onPressed: () {}, child: const Text('Menu 3.3')),
+            MenuItemButton(
+              onPressed: () {},
+              child: const Text('Menu 3.1'),
+            ),
+            MenuItemButton(
+              onPressed: () {},
+              child: const Text('Menu 3.2'),
+            ),
+            MenuItemButton(
+              onPressed: () {},
+              child: const Text('Menu 3.3'),
+            ),
           ],
           child: const Text('Menu 3'),
         ),
@@ -1920,7 +1952,10 @@ class _NavigationDrawerSectionState extends State<NavigationDrawerSection> {
       children: <Widget>[
         Padding(
           padding: const EdgeInsets.fromLTRB(28, 16, 16, 10),
-          child: Text('Mail', style: Theme.of(context).textTheme.titleSmall),
+          child: Text(
+            'Mail',
+            style: Theme.of(context).textTheme.titleSmall,
+          ),
         ),
         ...destinations.map((destination) {
           return NavigationDrawerDestination(
@@ -1932,7 +1967,10 @@ class _NavigationDrawerSectionState extends State<NavigationDrawerSection> {
         const Divider(indent: 28, endIndent: 28),
         Padding(
           padding: const EdgeInsets.fromLTRB(28, 16, 16, 10),
-          child: Text('Labels', style: Theme.of(context).textTheme.titleSmall),
+          child: Text(
+            'Labels',
+            style: Theme.of(context).textTheme.titleSmall,
+          ),
         ),
         ...labelDestinations.map((destination) {
           return NavigationDrawerDestination(
@@ -1955,14 +1993,26 @@ class ExampleDestination {
 }
 
 const List<ExampleDestination> destinations = <ExampleDestination>[
-  ExampleDestination('Inbox', Icon(Icons.inbox_outlined), Icon(Icons.inbox)),
-  ExampleDestination('Outbox', Icon(Icons.send_outlined), Icon(Icons.send)),
+  ExampleDestination(
+    'Inbox',
+    Icon(Icons.inbox_outlined),
+    Icon(Icons.inbox),
+  ),
+  ExampleDestination(
+    'Outbox',
+    Icon(Icons.send_outlined),
+    Icon(Icons.send),
+  ),
   ExampleDestination(
     'Favorites',
     Icon(Icons.favorite_outline),
     Icon(Icons.favorite),
   ),
-  ExampleDestination('Trash', Icon(Icons.delete_outline), Icon(Icons.delete)),
+  ExampleDestination(
+    'Trash',
+    Icon(Icons.delete_outline),
+    Icon(Icons.delete),
+  ),
 ];
 
 const List<ExampleDestination> labelDestinations = <ExampleDestination>[
@@ -1976,7 +2026,11 @@ const List<ExampleDestination> labelDestinations = <ExampleDestination>[
     Icon(Icons.bookmark_border),
     Icon(Icons.bookmark),
   ),
-  ExampleDestination('Work', Icon(Icons.bookmark_border), Icon(Icons.bookmark)),
+  ExampleDestination(
+    'Work',
+    Icon(Icons.bookmark_border),
+    Icon(Icons.bookmark),
+  ),
 ];
 
 class NavigationRails extends StatelessWidget {
@@ -2217,7 +2271,9 @@ class _MenusState extends State<Menus> {
                 label: const Text('Color'),
                 enableFilter: true,
                 dropdownMenuEntries: colorEntries,
-                inputDecorationTheme: const InputDecorationTheme(filled: true),
+                inputDecorationTheme: const InputDecorationTheme(
+                  filled: true,
+                ),
                 onSelected: (color) {
                   setState(() {
                     selectedColor = color;
@@ -2441,7 +2497,9 @@ class Carousels extends StatelessWidget {
             child: CarouselView(
               shape: RoundedRectangleBorder(
                 borderRadius: BorderRadius.circular(10),
-                side: BorderSide(color: Theme.of(context).colorScheme.outline),
+                side: BorderSide(
+                  color: Theme.of(context).colorScheme.outline,
+                ),
               ),
               shrinkExtent: 100,
               itemExtent: 180,
@@ -2461,7 +2519,9 @@ class Carousels extends StatelessWidget {
               itemSnapping: true,
               shape: RoundedRectangleBorder(
                 borderRadius: BorderRadius.circular(10),
-                side: BorderSide(color: Theme.of(context).colorScheme.outline),
+                side: BorderSide(
+                  color: Theme.of(context).colorScheme.outline,
+                ),
               ),
               shrinkExtent: 100,
               itemExtent: 180,
@@ -2536,9 +2596,13 @@ class _ComponentDecorationState extends State<ComponentDecoration> {
                     elevation: 0,
                     shape: RoundedRectangleBorder(
                       side: BorderSide(
-                        color: Theme.of(context).colorScheme.outlineVariant,
+                        color: Theme.of(
+                          context,
+                        ).colorScheme.outlineVariant,
+                      ),
+                      borderRadius: const BorderRadius.all(
+                        Radius.circular(12),
                       ),
-                      borderRadius: const BorderRadius.all(Radius.circular(12)),
                     ),
                     child: Padding(
                       padding: const EdgeInsets.symmetric(

material_3_demo/lib/src/elevation_screen.dart

@@ -65,7 +65,11 @@ class ElevationScreen extends StatelessWidget {
 const double narrowScreenWidthThreshold = 450;
 
 class ElevationGrid extends StatelessWidget {
-  const ElevationGrid({super.key, this.shadowColor, this.surfaceTintColor});
+  const ElevationGrid({
+    super.key,
+    this.shadowColor,
+    this.surfaceTintColor,
+  });
 
   final Color? shadowColor;
   final Color? surfaceTintColor;
@@ -135,7 +139,9 @@ class _ElevationCardState extends State<ElevationCard> {
 
   @override
   Widget build(BuildContext context) {
-    const BorderRadius borderRadius = BorderRadius.all(Radius.circular(4.0));
+    const BorderRadius borderRadius = BorderRadius.all(
+      Radius.circular(4.0),
+    );
     final Color color = Theme.of(context).colorScheme.surface;
 
     return Padding(

material_3_demo/lib/src/expanded_image_color_action.dart

@@ -32,9 +32,9 @@ class ExpandedImageColorAction extends StatelessWidget {
               index: i,
               select:
                   imageSelected == ColorImageProvider.values[i] &&
-                          colorSelectionMethod == ColorSelectionMethod.image
-                      ? null
-                      : () => handleImageSelect(i),
+                      colorSelectionMethod == ColorSelectionMethod.image
+                  ? null
+                  : () => handleImageSelect(i),
             ),
           ),
         ),
@@ -66,7 +66,9 @@ class _ImageButton extends StatelessWidget {
               child: ClipRRect(
                 borderRadius: BorderRadius.circular(4.0),
                 child: Image(
-                  image: NetworkImage(ColorImageProvider.values[index].url),
+                  image: NetworkImage(
+                    ColorImageProvider.values[index].url,
+                  ),
                 ),
               ),
             ),

material_3_demo/lib/src/home.dart

@@ -133,32 +133,30 @@ class _HomeState extends State<Home> with SingleTickerProviderStateMixin {
 
   PreferredSizeWidget _createAppBar() {
     return AppBar(
-      title:
-          widget.useMaterial3
-              ? const Text('Material 3')
-              : const Text('Material 2'),
-      actions:
-          !showMediumSizeLayout && !showLargeSizeLayout
-              ? [
-                BrightnessButton(
-                  handleBrightnessChange: widget.handleBrightnessChange,
-                ),
-                Material3Button(
-                  handleMaterialVersionChange:
-                      widget.handleMaterialVersionChange,
-                ),
-                ColorSeedButton(
-                  handleColorSelect: widget.handleColorSelect,
-                  colorSelected: widget.colorSelected,
-                  colorSelectionMethod: widget.colorSelectionMethod,
-                ),
-                ColorImageButton(
-                  handleImageSelect: widget.handleImageSelect,
-                  imageSelected: widget.imageSelected,
-                  colorSelectionMethod: widget.colorSelectionMethod,
-                ),
-              ]
-              : [Container()],
+      title: widget.useMaterial3
+          ? const Text('Material 3')
+          : const Text('Material 2'),
+      actions: !showMediumSizeLayout && !showLargeSizeLayout
+          ? [
+              BrightnessButton(
+                handleBrightnessChange: widget.handleBrightnessChange,
+              ),
+              Material3Button(
+                handleMaterialVersionChange:
+                    widget.handleMaterialVersionChange,
+              ),
+              ColorSeedButton(
+                handleColorSelect: widget.handleColorSelect,
+                colorSelected: widget.colorSelected,
+                colorSelectionMethod: widget.colorSelectionMethod,
+              ),
+              ColorImageButton(
+                handleImageSelect: widget.handleImageSelect,
+                imageSelected: widget.imageSelected,
+                colorSelectionMethod: widget.colorSelectionMethod,
+              ),
+            ]
+          : [Container()],
     );
   }
 
@@ -221,21 +219,20 @@ class _HomeState extends State<Home> with SingleTickerProviderStateMixin {
             trailing: Expanded(
               child: Padding(
                 padding: const EdgeInsets.only(bottom: 20),
-                child:
-                    showLargeSizeLayout
-                        ? ExpandedTrailingActions(
-                          useLightMode: widget.useLightMode,
-                          handleBrightnessChange: widget.handleBrightnessChange,
-                          useMaterial3: widget.useMaterial3,
-                          handleMaterialVersionChange:
-                              widget.handleMaterialVersionChange,
-                          handleImageSelect: widget.handleImageSelect,
-                          handleColorSelect: widget.handleColorSelect,
-                          colorSelectionMethod: widget.colorSelectionMethod,
-                          imageSelected: widget.imageSelected,
-                          colorSelected: widget.colorSelected,
-                        )
-                        : _trailingActions(),
+                child: showLargeSizeLayout
+                    ? ExpandedTrailingActions(
+                        useLightMode: widget.useLightMode,
+                        handleBrightnessChange: widget.handleBrightnessChange,
+                        useMaterial3: widget.useMaterial3,
+                        handleMaterialVersionChange:
+                            widget.handleMaterialVersionChange,
+                        handleImageSelect: widget.handleImageSelect,
+                        handleColorSelect: widget.handleColorSelect,
+                        colorSelectionMethod: widget.colorSelectionMethod,
+                        imageSelected: widget.imageSelected,
+                        colorSelected: widget.colorSelected,
+                      )
+                    : _trailingActions(),
               ),
             ),
           ),
@@ -258,7 +255,10 @@ class _HomeState extends State<Home> with SingleTickerProviderStateMixin {
 final List<NavigationRailDestination> _navRailDestinations = appBarDestinations
     .map(
       (destination) => NavigationRailDestination(
-        icon: Tooltip(message: destination.label, child: destination.icon),
+        icon: Tooltip(
+          message: destination.label,
+          child: destination.icon,
+        ),
         selectedIcon: Tooltip(
           message: destination.label,
           child: destination.selectedIcon,

material_3_demo/lib/src/scheme.dart

@@ -46,10 +46,9 @@ class _SchemePreviewState extends State<SchemePreview> {
             color: scheme.surface,
             borderRadius: BorderRadius.circular(12),
             border: Border.all(
-              color:
-                  theme.brightness == widget.brightness
-                      ? colors.outlineVariant
-                      : Colors.transparent,
+              color: theme.brightness == widget.brightness
+                  ? colors.outlineVariant
+                  : Colors.transparent,
             ),
           ),
           padding: const EdgeInsets.only(top: 16, left: 16, right: 16),

material_3_demo/lib/src/typography_screen.dart

@@ -9,9 +9,12 @@ class TypographyScreen extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final textTheme = Theme.of(
-      context,
-    ).textTheme.apply(displayColor: Theme.of(context).colorScheme.onSurface);
+    final textTheme =
+        Theme.of(
+          context,
+        ).textTheme.apply(
+          displayColor: Theme.of(context).colorScheme.onSurface,
+        );
     return Expanded(
       child: ListView(
         children: <Widget>[
@@ -40,15 +43,42 @@ class TypographyScreen extends StatelessWidget {
             name: 'Headline Small',
             style: textTheme.headlineSmall!,
           ),
-          TextStyleExample(name: 'Title Large', style: textTheme.titleLarge!),
-          TextStyleExample(name: 'Title Medium', style: textTheme.titleMedium!),
-          TextStyleExample(name: 'Title Small', style: textTheme.titleSmall!),
-          TextStyleExample(name: 'Label Large', style: textTheme.labelLarge!),
-          TextStyleExample(name: 'Label Medium', style: textTheme.labelMedium!),
-          TextStyleExample(name: 'Label Small', style: textTheme.labelSmall!),
-          TextStyleExample(name: 'Body Large', style: textTheme.bodyLarge!),
-          TextStyleExample(name: 'Body Medium', style: textTheme.bodyMedium!),
-          TextStyleExample(name: 'Body Small', style: textTheme.bodySmall!),
+          TextStyleExample(
+            name: 'Title Large',
+            style: textTheme.titleLarge!,
+          ),
+          TextStyleExample(
+            name: 'Title Medium',
+            style: textTheme.titleMedium!,
+          ),
+          TextStyleExample(
+            name: 'Title Small',
+            style: textTheme.titleSmall!,
+          ),
+          TextStyleExample(
+            name: 'Label Large',
+            style: textTheme.labelLarge!,
+          ),
+          TextStyleExample(
+            name: 'Label Medium',
+            style: textTheme.labelMedium!,
+          ),
+          TextStyleExample(
+            name: 'Label Small',
+            style: textTheme.labelSmall!,
+          ),
+          TextStyleExample(
+            name: 'Body Large',
+            style: textTheme.bodyLarge!,
+          ),
+          TextStyleExample(
+            name: 'Body Medium',
+            style: textTheme.bodyMedium!,
+          ),
+          TextStyleExample(
+            name: 'Body Small',
+            style: textTheme.bodySmall!,
+          ),
         ],
       ),
     );
@@ -56,7 +86,11 @@ class TypographyScreen extends StatelessWidget {
 }
 
 class TextStyleExample extends StatelessWidget {
-  const TextStyleExample({super.key, required this.name, required this.style});
+  const TextStyleExample({
+    super.key,
+    required this.name,
+    required this.style,
+  });
 
   final String name;
   final TextStyle style;

material_3_demo/pubspec.yaml

@@ -2,18 +2,16 @@ name: material_3_demo
 description:
   A Flutter project showcasing supported Material 3 components, typography, color system and elevation.
   Supports different light/dark mode, color seed, and comparison to Material 2.
-
 publish_to: "none"
-
 version: 1.0.0+1
+resolution: workspace
 
 environment:
-  sdk: ^3.7.0-0
+  sdk: ^3.9.0-0
 
 dependencies:
   flutter:
     sdk: flutter
-
   cupertino_icons: ^1.0.2
   url_launcher: ^6.1.8
 
@@ -24,6 +22,5 @@ dev_dependencies:
     sdk: flutter
   integration_test:
     sdk: flutter
-
 flutter:
   uses-material-design: true

material_3_demo/test/color_screen_test.dart

@@ -90,7 +90,10 @@ void main() {
     );
     expect(find.text('Light ColorScheme'), findsOneWidget);
     expect(find.text('Dark ColorScheme'), findsOneWidget);
-    expect(find.byType(SchemePreview, skipOffstage: false), findsNWidgets(2));
+    expect(
+      find.byType(SchemePreview, skipOffstage: false),
+      findsNWidgets(2),
+    );
   });
 
   testWidgets(
@@ -107,7 +110,9 @@ void main() {
       const testLabel = 'Test Label';
       const testTone = '50';
 
-      final gesture = await tester.createGesture(kind: PointerDeviceKind.mouse);
+      final gesture = await tester.createGesture(
+        kind: PointerDeviceKind.mouse,
+      );
 
       // Wrap in MaterialApp + Scaffold so we can show SnackBars
       await tester.pumpWidget(

material_3_demo/test/component_screen_test.dart

@@ -20,14 +20,26 @@ void main() {
       findsOneWidget,
     );
     expect(find.widgetWithIcon(AppBar, Icons.filter_2), findsOneWidget);
-    expect(find.widgetWithIcon(AppBar, Icons.palette_outlined), findsOneWidget);
+    expect(
+      find.widgetWithIcon(AppBar, Icons.palette_outlined),
+      findsOneWidget,
+    );
 
     // Elements on the component screen
     // Common buttons
-    expect(find.widgetWithText(ElevatedButton, 'Elevated'), findsNWidgets(2));
+    expect(
+      find.widgetWithText(ElevatedButton, 'Elevated'),
+      findsNWidgets(2),
+    );
     expect(find.widgetWithText(FilledButton, 'Filled'), findsNWidgets(2));
-    expect(find.widgetWithText(FilledButton, 'Filled tonal'), findsNWidgets(2));
-    expect(find.widgetWithText(OutlinedButton, 'Outlined'), findsNWidgets(2));
+    expect(
+      find.widgetWithText(FilledButton, 'Filled tonal'),
+      findsNWidgets(2),
+    );
+    expect(
+      find.widgetWithText(OutlinedButton, 'Outlined'),
+      findsNWidgets(2),
+    );
     expect(find.widgetWithText(TextButton, 'Text'), findsNWidgets(2));
     expect(find.widgetWithText(Buttons, 'Icon'), findsNWidgets(5));
 
@@ -36,7 +48,10 @@ void main() {
       find.byType(FloatingActionButton),
       findsNWidgets(6),
     ); // 2 more show up in the bottom app bar. 1 more in the navigation rail
-    expect(find.widgetWithText(FloatingActionButton, 'Create'), findsOneWidget);
+    expect(
+      find.widgetWithText(FloatingActionButton, 'Create'),
+      findsOneWidget,
+    );
 
     // Icon buttons
     expect(
@@ -52,13 +67,18 @@ void main() {
     expect(find.byType(Badge), findsNWidgets(4));
 
     // Progress indicators
-    Finder circularProgressIndicator = find.byType(CircularProgressIndicator);
+    Finder circularProgressIndicator = find.byType(
+      CircularProgressIndicator,
+    );
     expect(circularProgressIndicator, findsOneWidget);
     Finder linearProgressIndicator = find.byType(LinearProgressIndicator);
     expect(linearProgressIndicator, findsOneWidget);
 
     // Snackbar
-    expect(find.widgetWithText(TextButton, 'Show snackbar'), findsOneWidget);
+    expect(
+      find.widgetWithText(TextButton, 'Show snackbar'),
+      findsOneWidget,
+    );
 
     // Bottom sheet
     expect(
@@ -128,8 +148,14 @@ void main() {
     expect(find.byType(InputChip), findsNWidgets(2));
 
     // Date and time pickers
-    expect(find.widgetWithText(DatePicker, 'Show date picker'), findsOneWidget);
-    expect(find.widgetWithText(TimePicker, 'Show time picker'), findsOneWidget);
+    expect(
+      find.widgetWithText(DatePicker, 'Show date picker'),
+      findsOneWidget,
+    );
+    expect(
+      find.widgetWithText(TimePicker, 'Show time picker'),
+      findsOneWidget,
+    );
 
     // Menus
     expect(find.byType(MenuAnchor), findsNWidgets(5));
@@ -152,175 +178,221 @@ void main() {
     expect(find.widgetWithText(TextField, 'Outlined'), findsNWidgets(2));
   });
 
-  testWidgets('NavigationRail doesn\'t show when width value is small than 1000 '
-      '(in Portrait mode or narrow screen)', (tester) async {
-    widgetSetup(tester, 999, windowHeight: 7000);
-    await tester.pumpWidget(const App());
-    await tester.pumpAndSettle();
+  testWidgets(
+    'NavigationRail doesn\'t show when width value is small than 1000 '
+    '(in Portrait mode or narrow screen)',
+    (tester) async {
+      widgetSetup(tester, 999, windowHeight: 7000);
+      await tester.pumpWidget(const App());
+      await tester.pumpAndSettle();
 
-    // When screen width is less than 1000, NavigationBar will show. At the same
-    // time, the NavigationBar example still show up in the navigation group.
-    expect(
-      find.byType(NavigationBars),
-      findsNWidgets(3),
-    ); // The real navBar, badges example and navBar example
-    expect(find.widgetWithText(NavigationBar, 'Components'), findsOneWidget);
-    expect(find.widgetWithText(NavigationBar, 'Color'), findsOneWidget);
-    expect(find.widgetWithText(NavigationBar, 'Typography'), findsOneWidget);
-    expect(find.widgetWithText(NavigationBar, 'Elevation'), findsOneWidget);
+      // When screen width is less than 1000, NavigationBar will show. At the same
+      // time, the NavigationBar example still show up in the navigation group.
+      expect(
+        find.byType(NavigationBars),
+        findsNWidgets(3),
+      ); // The real navBar, badges example and navBar example
+      expect(
+        find.widgetWithText(NavigationBar, 'Components'),
+        findsOneWidget,
+      );
+      expect(find.widgetWithText(NavigationBar, 'Color'), findsOneWidget);
+      expect(
+        find.widgetWithText(NavigationBar, 'Typography'),
+        findsOneWidget,
+      );
+      expect(
+        find.widgetWithText(NavigationBar, 'Elevation'),
+        findsOneWidget,
+      );
 
-    expect(find.widgetWithText(NavigationBar, 'Explore'), findsOneWidget);
-    expect(find.widgetWithText(NavigationBar, 'Pets'), findsOneWidget);
-    expect(find.widgetWithText(NavigationBar, 'Account'), findsOneWidget);
-  });
+      expect(
+        find.widgetWithText(NavigationBar, 'Explore'),
+        findsOneWidget,
+      );
+      expect(find.widgetWithText(NavigationBar, 'Pets'), findsOneWidget);
+      expect(
+        find.widgetWithText(NavigationBar, 'Account'),
+        findsOneWidget,
+      );
+    },
+  );
 
-  testWidgets('NavigationRail shows when width value is greater than or equal '
-      'to 1000 (in Landscape mode or wider screen)', (tester) async {
-    widgetSetup(tester, 1001, windowHeight: 3000);
-    await tester.pumpWidget(const App());
-    await tester.pumpAndSettle();
+  testWidgets(
+    'NavigationRail shows when width value is greater than or equal '
+    'to 1000 (in Landscape mode or wider screen)',
+    (tester) async {
+      widgetSetup(tester, 1001, windowHeight: 3000);
+      await tester.pumpWidget(const App());
+      await tester.pumpAndSettle();
 
-    // When screen width is greater than or equal to 1000, NavigationRail will show.
-    // At the same time, the NavigationBar will NOT show.
-    expect(find.byType(NavigationRail), findsNWidgets(2));
-    expect(find.byType(Tooltip, skipOffstage: false), findsWidgets);
-    expect(find.widgetWithText(NavigationRail, 'Components'), findsOneWidget);
-    expect(find.widgetWithText(NavigationRail, 'Color'), findsOneWidget);
-    expect(find.widgetWithText(NavigationRail, 'Typography'), findsOneWidget);
-    expect(find.widgetWithText(NavigationRail, 'Elevation'), findsOneWidget);
+      // When screen width is greater than or equal to 1000, NavigationRail will show.
+      // At the same time, the NavigationBar will NOT show.
+      expect(find.byType(NavigationRail), findsNWidgets(2));
+      expect(find.byType(Tooltip, skipOffstage: false), findsWidgets);
+      expect(
+        find.widgetWithText(NavigationRail, 'Components'),
+        findsOneWidget,
+      );
+      expect(find.widgetWithText(NavigationRail, 'Color'), findsOneWidget);
+      expect(
+        find.widgetWithText(NavigationRail, 'Typography'),
+        findsOneWidget,
+      );
+      expect(
+        find.widgetWithText(NavigationRail, 'Elevation'),
+        findsOneWidget,
+      );
 
-    expect(find.widgetWithText(NavigationBar, 'Explore'), findsOneWidget);
-    expect(find.widgetWithText(NavigationBar, 'Pets'), findsOneWidget);
-    expect(find.widgetWithText(NavigationBar, 'Account'), findsOneWidget);
+      expect(
+        find.widgetWithText(NavigationBar, 'Explore'),
+        findsOneWidget,
+      );
+      expect(find.widgetWithText(NavigationBar, 'Pets'), findsOneWidget);
+      expect(
+        find.widgetWithText(NavigationBar, 'Account'),
+        findsOneWidget,
+      );
 
-    // the Navigation bar should be out of screen.
-    final RenderBox box = tester.renderObject(
-      find.widgetWithText(NavigationBar, 'Components'),
-    );
-    expect(box.localToGlobal(Offset.zero), const Offset(0.0, 3080.0));
-  });
+      // the Navigation bar should be out of screen.
+      final RenderBox box = tester.renderObject(
+        find.widgetWithText(NavigationBar, 'Components'),
+      );
+      expect(box.localToGlobal(Offset.zero), const Offset(0.0, 3080.0));
+    },
+  );
 
-  testWidgets('Material version switches between Material3 and Material2 when '
-      'the version icon is clicked', (tester) async {
-    widgetSetup(tester, 450, windowHeight: 7000);
-    await tester.pumpWidget(const App());
-    BuildContext defaultElevatedButton = tester.firstElement(
-      find.byType(ElevatedButton),
-    );
-    BuildContext defaultIconButton = tester.firstElement(
-      find.byType(IconButton),
-    );
-    BuildContext defaultFAB = tester.firstElement(
-      find.byType(FloatingActionButton),
-    );
-    BuildContext defaultCard = tester.firstElement(
-      find.widgetWithText(Card, 'Elevated'),
-    );
-    BuildContext defaultChip = tester.firstElement(
-      find.widgetWithText(ActionChip, 'Assist'),
-    );
-    Finder dialog = find.text('Show dialog');
-    await tester.tap(dialog);
-    await tester.pumpAndSettle(const Duration(microseconds: 500));
-    BuildContext defaultAlertDialog = tester.element(find.byType(AlertDialog));
-    expect(Theme.of(defaultAlertDialog).useMaterial3, true);
-    Finder dismiss = find.text('Okay');
-    await tester.tap(dismiss);
-    await tester.pumpAndSettle(const Duration(microseconds: 500));
+  testWidgets(
+    'Material version switches between Material3 and Material2 when '
+    'the version icon is clicked',
+    (tester) async {
+      widgetSetup(tester, 450, windowHeight: 7000);
+      await tester.pumpWidget(const App());
+      BuildContext defaultElevatedButton = tester.firstElement(
+        find.byType(ElevatedButton),
+      );
+      BuildContext defaultIconButton = tester.firstElement(
+        find.byType(IconButton),
+      );
+      BuildContext defaultFAB = tester.firstElement(
+        find.byType(FloatingActionButton),
+      );
+      BuildContext defaultCard = tester.firstElement(
+        find.widgetWithText(Card, 'Elevated'),
+      );
+      BuildContext defaultChip = tester.firstElement(
+        find.widgetWithText(ActionChip, 'Assist'),
+      );
+      Finder dialog = find.text('Show dialog');
+      await tester.tap(dialog);
+      await tester.pumpAndSettle(const Duration(microseconds: 500));
+      BuildContext defaultAlertDialog = tester.element(
+        find.byType(AlertDialog),
+      );
+      expect(Theme.of(defaultAlertDialog).useMaterial3, true);
+      Finder dismiss = find.text('Okay');
+      await tester.tap(dismiss);
+      await tester.pumpAndSettle(const Duration(microseconds: 500));
 
-    expect(find.widgetWithIcon(AppBar, Icons.filter_2), findsOneWidget);
-    expect(find.widgetWithIcon(AppBar, Icons.filter_3), findsNothing);
-    expect(find.text('Material 3'), findsOneWidget);
-    expect(Theme.of(defaultElevatedButton).useMaterial3, true);
-    expect(Theme.of(defaultIconButton).useMaterial3, true);
-    expect(Theme.of(defaultFAB).useMaterial3, true);
-    expect(Theme.of(defaultCard).useMaterial3, true);
-    expect(Theme.of(defaultChip).useMaterial3, true);
+      expect(find.widgetWithIcon(AppBar, Icons.filter_2), findsOneWidget);
+      expect(find.widgetWithIcon(AppBar, Icons.filter_3), findsNothing);
+      expect(find.text('Material 3'), findsOneWidget);
+      expect(Theme.of(defaultElevatedButton).useMaterial3, true);
+      expect(Theme.of(defaultIconButton).useMaterial3, true);
+      expect(Theme.of(defaultFAB).useMaterial3, true);
+      expect(Theme.of(defaultCard).useMaterial3, true);
+      expect(Theme.of(defaultChip).useMaterial3, true);
 
-    Finder appbarM3Icon = find.descendant(
-      of: find.byType(AppBar),
-      matching: find.widgetWithIcon(IconButton, Icons.filter_2),
-    );
-    await tester.tap(appbarM3Icon);
-    await tester.pumpAndSettle(const Duration(microseconds: 500));
-    BuildContext updatedElevatedButton = tester.firstElement(
-      find.byType(ElevatedButton),
-    );
-    BuildContext updatedIconButton = tester.firstElement(
-      find.byType(IconButton),
-    );
-    BuildContext updatedFAB = tester.firstElement(
-      find.byType(FloatingActionButton),
-    );
-    BuildContext updatedCard = tester.firstElement(find.byType(Card));
-    BuildContext updatedChip = tester.firstElement(
-      find.widgetWithText(ActionChip, 'Assist'),
-    );
-    Finder updatedDialog = find.text('Show dialog');
-    await tester.tap(updatedDialog);
-    await tester.pumpAndSettle(const Duration(microseconds: 500));
-    BuildContext updatedAlertDialog = tester.firstElement(
-      find.byType(AlertDialog),
-    );
-    expect(Theme.of(updatedAlertDialog).useMaterial3, false);
-    Finder updatedDismiss = find.text('Dismiss');
-    await tester.tap(updatedDismiss);
-    await tester.pumpAndSettle(const Duration(microseconds: 500));
+      Finder appbarM3Icon = find.descendant(
+        of: find.byType(AppBar),
+        matching: find.widgetWithIcon(IconButton, Icons.filter_2),
+      );
+      await tester.tap(appbarM3Icon);
+      await tester.pumpAndSettle(const Duration(microseconds: 500));
+      BuildContext updatedElevatedButton = tester.firstElement(
+        find.byType(ElevatedButton),
+      );
+      BuildContext updatedIconButton = tester.firstElement(
+        find.byType(IconButton),
+      );
+      BuildContext updatedFAB = tester.firstElement(
+        find.byType(FloatingActionButton),
+      );
+      BuildContext updatedCard = tester.firstElement(find.byType(Card));
+      BuildContext updatedChip = tester.firstElement(
+        find.widgetWithText(ActionChip, 'Assist'),
+      );
+      Finder updatedDialog = find.text('Show dialog');
+      await tester.tap(updatedDialog);
+      await tester.pumpAndSettle(const Duration(microseconds: 500));
+      BuildContext updatedAlertDialog = tester.firstElement(
+        find.byType(AlertDialog),
+      );
+      expect(Theme.of(updatedAlertDialog).useMaterial3, false);
+      Finder updatedDismiss = find.text('Dismiss');
+      await tester.tap(updatedDismiss);
+      await tester.pumpAndSettle(const Duration(microseconds: 500));
 
-    expect(find.widgetWithIcon(AppBar, Icons.filter_3), findsOneWidget);
-    expect(find.widgetWithIcon(AppBar, Icons.filter_2), findsNothing);
-    expect(find.text('Material 2'), findsOneWidget);
-    expect(Theme.of(updatedElevatedButton).useMaterial3, false);
-    expect(Theme.of(updatedIconButton).useMaterial3, false);
-    expect(Theme.of(updatedFAB).useMaterial3, false);
-    expect(Theme.of(updatedCard).useMaterial3, false);
-    expect(Theme.of(updatedChip).useMaterial3, false);
-  });
+      expect(find.widgetWithIcon(AppBar, Icons.filter_3), findsOneWidget);
+      expect(find.widgetWithIcon(AppBar, Icons.filter_2), findsNothing);
+      expect(find.text('Material 2'), findsOneWidget);
+      expect(Theme.of(updatedElevatedButton).useMaterial3, false);
+      expect(Theme.of(updatedIconButton).useMaterial3, false);
+      expect(Theme.of(updatedFAB).useMaterial3, false);
+      expect(Theme.of(updatedCard).useMaterial3, false);
+      expect(Theme.of(updatedChip).useMaterial3, false);
+    },
+  );
 
-  testWidgets('Other screens become Material2 mode after changing mode from '
-      'main screen', (tester) async {
-    await tester.pumpWidget(const App());
-    Finder appbarM2Icon = find.descendant(
-      of: find.byType(AppBar),
-      matching: find.widgetWithIcon(IconButton, Icons.filter_2),
-    );
-    await tester.tap(appbarM2Icon);
-    Finder secondScreenIcon = find.descendant(
-      of: find.byType(NavigationBar),
-      matching: find.widgetWithIcon(
-        NavigationDestination,
-        Icons.format_paint_outlined,
-      ),
-    );
-    await tester.tap(secondScreenIcon);
-    await tester.pumpAndSettle(const Duration(microseconds: 500));
-    BuildContext lightThemeText = tester.element(
-      find.text('Light ColorScheme'),
-    );
-    expect(Theme.of(lightThemeText).useMaterial3, false);
-    Finder thirdScreenIcon = find.descendant(
-      of: find.byType(NavigationBar),
-      matching: find.widgetWithIcon(
-        NavigationDestination,
-        Icons.text_snippet_outlined,
-      ),
-    );
-    await tester.tap(thirdScreenIcon);
-    await tester.pumpAndSettle(const Duration(microseconds: 500));
-    BuildContext displayLargeText = tester.element(find.text('Display Large'));
-    expect(Theme.of(displayLargeText).useMaterial3, false);
-    Finder fourthScreenIcon = find.descendant(
-      of: find.byType(NavigationBar),
-      matching: find.widgetWithIcon(
-        NavigationDestination,
-        Icons.invert_colors_on_outlined,
-      ),
-    );
-    await tester.tap(fourthScreenIcon);
-    await tester.pumpAndSettle(const Duration(microseconds: 500));
-    BuildContext material = tester.firstElement(find.byType(Material));
-    expect(Theme.of(material).useMaterial3, false);
-  });
+  testWidgets(
+    'Other screens become Material2 mode after changing mode from '
+    'main screen',
+    (tester) async {
+      await tester.pumpWidget(const App());
+      Finder appbarM2Icon = find.descendant(
+        of: find.byType(AppBar),
+        matching: find.widgetWithIcon(IconButton, Icons.filter_2),
+      );
+      await tester.tap(appbarM2Icon);
+      Finder secondScreenIcon = find.descendant(
+        of: find.byType(NavigationBar),
+        matching: find.widgetWithIcon(
+          NavigationDestination,
+          Icons.format_paint_outlined,
+        ),
+      );
+      await tester.tap(secondScreenIcon);
+      await tester.pumpAndSettle(const Duration(microseconds: 500));
+      BuildContext lightThemeText = tester.element(
+        find.text('Light ColorScheme'),
+      );
+      expect(Theme.of(lightThemeText).useMaterial3, false);
+      Finder thirdScreenIcon = find.descendant(
+        of: find.byType(NavigationBar),
+        matching: find.widgetWithIcon(
+          NavigationDestination,
+          Icons.text_snippet_outlined,
+        ),
+      );
+      await tester.tap(thirdScreenIcon);
+      await tester.pumpAndSettle(const Duration(microseconds: 500));
+      BuildContext displayLargeText = tester.element(
+        find.text('Display Large'),
+      );
+      expect(Theme.of(displayLargeText).useMaterial3, false);
+      Finder fourthScreenIcon = find.descendant(
+        of: find.byType(NavigationBar),
+        matching: find.widgetWithIcon(
+          NavigationDestination,
+          Icons.invert_colors_on_outlined,
+        ),
+      );
+      await tester.tap(fourthScreenIcon);
+      await tester.pumpAndSettle(const Duration(microseconds: 500));
+      BuildContext material = tester.firstElement(find.byType(Material));
+      expect(Theme.of(material).useMaterial3, false);
+    },
+  );
 
   testWidgets('Brightness mode switches between dark and light when'
       'the brightness icon is clicked', (tester) async {

material_3_demo/test/elevation_screen_test.dart

@@ -34,7 +34,10 @@ void main() {
       expect(tintIconOnBar, findsNothing);
       Finder selectedTintIconOnBar = find.descendant(
         of: find.byType(NavigationBar),
-        matching: find.widgetWithIcon(NavigationDestination, Icons.opacity),
+        matching: find.widgetWithIcon(
+          NavigationDestination,
+          Icons.opacity,
+        ),
       );
       expect(selectedTintIconOnBar, findsOneWidget);
       expect(find.text('Surface Tint Color Only'), findsOneWidget);
@@ -69,14 +72,19 @@ void main() {
     },
   );
 
-  testWidgets('Surface Tones screen shows correct content', (tester) async {
+  testWidgets('Surface Tones screen shows correct content', (
+    tester,
+  ) async {
     await tester.pumpWidget(
       const MaterialApp(
         home: Scaffold(body: Row(children: [ElevationScreen()])),
       ),
     );
     expect(find.text('Surface Tint Color Only'), findsOneWidget);
-    expect(find.text('Surface Tint Color and Shadow Color'), findsOneWidget);
+    expect(
+      find.text('Surface Tint Color and Shadow Color'),
+      findsOneWidget,
+    );
     expect(find.text('Shadow Color Only'), findsOneWidget);
     expect(find.byType(ElevationGrid), findsNWidgets(3));
     expect(find.byType(ElevationCard), findsNWidgets(18));