Add app bar and tab bar to a11y assessment app (#152904)

*Replace this paragraph with a description of what this PR is changing or adding, and why. Consider including before/after screenshots.*

*List which issues are fixed by this PR. You must list at least one issue. An issue is not required if the PR fixes something trivial like a typo.*

*If you had to change anything in the [flutter/tests] repo, include a link to the migration guide as per the [breaking change policy].*

dev/a11y_assessments/lib/use_cases/app_bar.dart

@@ -0,0 +1,120 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/material.dart';
+
+import 'use_cases.dart';
+
+class AppBarUseCase extends UseCase {
+  @override
+  String get name => 'AppBar';
+
+  @override
+  String get route => '/app-bar';
+
+  @override
+  Widget build(BuildContext context) => const MainWidget();
+}
+
+class MainWidget extends StatefulWidget {
+  const MainWidget({super.key});
+
+  @override
+  State<MainWidget> createState() => MainWidgetState();
+}
+
+class MainWidgetState extends State<MainWidget> {
+  int currentIndex = 0;
+
+  void _onChanged(int? value) {
+    setState(() {
+      currentIndex = value!;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: <PreferredSizeWidget>[
+        AppBar(
+          backgroundColor: Theme.of(context).colorScheme.inversePrimary,
+          title: Semantics(headingLevel: 1, child: const Text('AppBar')),
+        ),
+        AppBar(
+          backgroundColor: Theme.of(context).colorScheme.inversePrimary,
+          title: Semantics(headingLevel: 1, child: const Text('AppBar')),
+          actions: <Widget>[
+            IconButton(
+              icon: const Icon(Icons.add_alert),
+              tooltip: 'Show Snackbar',
+              onPressed: () {
+                ScaffoldMessenger.of(context).showSnackBar(
+                    const SnackBar(content: Text('This is a snackbar')));
+              },
+            ),
+            IconButton(
+              icon: const Icon(Icons.navigate_next),
+              tooltip: 'Go to the next page',
+              onPressed: () {
+                Navigator.push(context, MaterialPageRoute<void>(
+                  builder: (BuildContext context) {
+                    return Scaffold(
+                      appBar: AppBar(
+                        backgroundColor:
+                            Theme.of(context).colorScheme.inversePrimary,
+          title: Semantics(headingLevel: 1, child: const Text('Next Page')),
+                      ),
+                      body: const Center(
+                        child: Text(
+                          'This is the next page',
+                          style: TextStyle(fontSize: 24),
+                        ),
+                      ),
+                    );
+                  },
+                ));
+              },
+            ),
+          ],
+        ),
+        AppBar(
+          backgroundColor: Theme.of(context).colorScheme.inversePrimary,
+          title: Semantics(headingLevel: 1, child: const Text('AppBar')),
+          actions: <Widget>[
+            TextButton(
+              onPressed: () {},
+              child: const Text('Action 1'),
+            ),
+            TextButton(
+              onPressed: () {},
+              child: const Text('Action 2'),
+            ),
+          ],
+        ),
+      ][currentIndex],
+      body: ListView(
+        children: <Widget>[
+          RadioListTile<int>(
+            title: const Text('1. Simple app bar'),
+            value: 0,
+            groupValue: currentIndex,
+            onChanged: _onChanged,
+          ),
+          RadioListTile<int>(
+            title: const Text('2. App bar with actions'),
+            value: 1,
+            groupValue: currentIndex,
+            onChanged: _onChanged,
+          ),
+          RadioListTile<int>(
+            title: const Text('3. App bar with text buttons'),
+            value: 2,
+            groupValue: currentIndex,
+            onChanged: _onChanged,
+          ),
+        ],
+      ),
+    );
+  }
+}

dev/a11y_assessments/lib/use_cases/tab_bar_view.dart

@@ -0,0 +1,66 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/material.dart';
+
+import 'use_cases.dart';
+
+class TabBarViewUseCase extends UseCase {
+
+  @override
+  String get name => 'TabBarView';
+
+  @override
+  String get route => '/tab-bar-view';
+
+  @override
+  Widget build(BuildContext context) => const TabBarViewExample();
+}
+
+
+class TabBarViewExample extends StatelessWidget {
+  const TabBarViewExample({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return DefaultTabController(
+      initialIndex: 1,
+      length: 3,
+      child: Scaffold(
+        appBar: AppBar(
+          title: Semantics(headingLevel: 1, child: const Text('TabBarView Sample')),
+          bottom: const TabBar(
+            tabs: <Widget>[
+              Tab(
+                icon: Icon(Icons.cloud_outlined),
+                text: 'Cloudy',
+              ),
+              Tab(
+                icon: Icon(Icons.beach_access_sharp),
+                text: 'Rainy',
+              ),
+              Tab(
+                icon: Icon(Icons.brightness_5_sharp),
+                text: 'Sunny',
+              ),
+            ],
+          ),
+        ),
+        body: const TabBarView(
+          children: <Widget>[
+            Center(
+              child: Text("It's cloudy here"),
+            ),
+            Center(
+              child: Text("It's rainy here"),
+            ),
+            Center(
+              child: Text("It's sunny here"),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

dev/a11y_assessments/lib/use_cases/use_cases.dart

@@ -6,6 +6,7 @@ import 'package:flutter/widgets.dart';
 
 import '../common/dynamic_title.dart';
 import 'action_chip.dart';
+import 'app_bar.dart';
 import 'auto_complete.dart';
 import 'badge.dart';
 import 'card.dart';
@@ -22,6 +23,7 @@ import 'radio_list_tile.dart';
 import 'slider.dart';
 import 'snack_bar.dart';
 import 'switch_list_tile.dart';
+import 'tab_bar_view.dart';
 import 'text_button.dart';
 import 'text_field.dart';
 import 'text_field_password.dart';
@@ -61,4 +63,6 @@ final List<UseCase> useCases = <UseCase>[
   DrawerUseCase(),
   NavigationDrawerUseCase(),
   NavigationRailUseCase(),
+  AppBarUseCase(),
+  TabBarViewUseCase(),
 ];

dev/a11y_assessments/test/app_bar_test.dart

@@ -0,0 +1,15 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:a11y_assessments/use_cases/app_bar.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'test_utils.dart';
+
+void main() {
+  testWidgets('app bar can run', (WidgetTester tester) async {
+    await pumpsUseCase(tester, AppBarUseCase());
+    expect(find.text('AppBar'), findsOneWidget);
+  });
+}

dev/a11y_assessments/test/tab_bar_view_test.dart

@@ -0,0 +1,16 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:a11y_assessments/use_cases/tab_bar_view.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'test_utils.dart';
+
+void main() {
+  testWidgets('tab bar view can run', (WidgetTester tester) async {
+    await pumpsUseCase(tester, TabBarViewUseCase());
+    expect(find.byType(TabBar), findsOneWidget);
+  });
+}