Update date picker examples, remove unused variables and add missing tests (#121528)

Update date picker examples, remove unused variables and add missing tests

examples/api/lib/material/date_picker/show_date_picker.0.dart

@@ -6,34 +6,32 @@
 
 import 'package:flutter/material.dart';
 
-void main() => runApp(const MyApp());
+void main() => runApp(const DatePickerApp());
 
-class MyApp extends StatelessWidget {
-  const MyApp({super.key});
-
-  static const String _title = 'Flutter Code Sample';
+class DatePickerApp extends StatelessWidget {
+  const DatePickerApp({super.key});
 
   @override
   Widget build(BuildContext context) {
-    return const MaterialApp(
+    return MaterialApp(
+      theme: ThemeData(useMaterial3: true),
       restorationScopeId: 'app',
-      title: _title,
-      home: MyStatefulWidget(restorationId: 'main'),
+      home: const DatePickerExample(restorationId: 'main'),
     );
   }
 }
 
-class MyStatefulWidget extends StatefulWidget {
-  const MyStatefulWidget({super.key, this.restorationId});
+class DatePickerExample extends StatefulWidget {
+  const DatePickerExample({super.key, this.restorationId});
 
   final String? restorationId;
 
   @override
-  State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
+  State<DatePickerExample> createState() => _DatePickerExampleState();
 }
 
 /// RestorationProperty objects can be used because of RestorationMixin.
-class _MyStatefulWidgetState extends State<MyStatefulWidget>
+class _DatePickerExampleState extends State<DatePickerExample>
     with RestorationMixin {
   // In this example, the restoration ID for the mixin is passed in through
   // the [StatefulWidget]'s constructor.

examples/api/lib/material/date_picker/show_date_range_picker.0.dart

@@ -6,34 +6,33 @@
 
 import 'package:flutter/material.dart';
 
-void main() => runApp(const MyApp());
+void main() => runApp(const DatePickerApp());
 
-class MyApp extends StatelessWidget {
-  const MyApp({super.key});
-
-  static const String _title = 'Flutter Code Sample';
+class DatePickerApp extends StatelessWidget {
+  const DatePickerApp({super.key});
 
   @override
   Widget build(BuildContext context) {
-    return const MaterialApp(
+    return MaterialApp(
+      theme: ThemeData(useMaterial3: true),
       restorationScopeId: 'app',
-      title: _title,
-      home: MyStatefulWidget(restorationId: 'main'),
+      home: const DatePickerExample(restorationId: 'main'),
     );
   }
 }
 
-class MyStatefulWidget extends StatefulWidget {
-  const MyStatefulWidget({super.key, this.restorationId});
+
+class DatePickerExample extends StatefulWidget {
+  const DatePickerExample({super.key, this.restorationId});
 
   final String? restorationId;
 
   @override
-  State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
+  State<DatePickerExample> createState() => _DatePickerExampleState();
 }
 
 /// RestorationProperty objects can be used because of RestorationMixin.
-class _MyStatefulWidgetState extends State<MyStatefulWidget>
+class _DatePickerExampleState extends State<DatePickerExample>
     with RestorationMixin {
   // In this example, the restoration ID for the mixin is passed in through
   // the [StatefulWidget]'s constructor.

examples/api/lib/material/filter_chip/filter_chip.0.dart

@@ -16,8 +16,13 @@ class ChipApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      theme: ThemeData(colorSchemeSeed: const Color(0xff6750a4), useMaterial3: true),
-      home: const FilterChipExample(),
+      theme: ThemeData(useMaterial3: true),
+      home: Scaffold(
+        appBar: AppBar(
+          title: const Text('FilterChip Sample'),
+        ),
+        body: const FilterChipExample(),
+      ),
     );
   }
 }
@@ -30,49 +35,43 @@ class FilterChipExample extends StatefulWidget {
 }
 
 class _FilterChipExampleState extends State<FilterChipExample> {
-  bool favorite = false;
-  final List<String> _filters = <String>[];
+  Set<ExerciseFilter> filters = <ExerciseFilter>{};
 
   @override
   Widget build(BuildContext context) {
     final TextTheme textTheme = Theme.of(context).textTheme;
 
-    return Scaffold(
-      appBar: AppBar(
-        title: const Text('FilterChip Sample'),
-      ),
-      body: Center(
-        child: Column(
-          mainAxisAlignment: MainAxisAlignment.center,
-          children: <Widget>[
-            Text('Choose an exercise', style: textTheme.labelLarge),
-            const SizedBox(height: 5.0),
-            Wrap(
-              spacing: 5.0,
-              children: ExerciseFilter.values.map((ExerciseFilter exercise) {
-                return FilterChip(
-                  label: Text(exercise.name),
-                  selected:_filters.contains(exercise.name),
-                  onSelected: (bool value) {
-                    setState(() {
-                      if (value) {
-                        if (!_filters.contains(exercise.name)) {
-                          _filters.add(exercise.name);
-                        }
-                      } else {
-                        _filters.removeWhere((String name) {
-                          return name == exercise.name;
-                        });
-                      }
-                    });
-                  },
-                );
-              }).toList(),
-            ),
-            const SizedBox(height: 10.0),
-            Text('Looking for: ${_filters.join(', ')}')
-          ],
-        ),
+    return Center(
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: <Widget>[
+          Text('Choose an exercise', style: textTheme.labelLarge),
+          const SizedBox(height: 5.0),
+          Wrap(
+            spacing: 5.0,
+            children: ExerciseFilter.values.map((ExerciseFilter exercise) {
+              return FilterChip(
+                label: Text(exercise.name),
+                selected: filters.contains(exercise),
+                onSelected: (bool selected) {
+                  setState(() {
+                    if (selected) {
+                      filters.add(exercise);
+                    } else {
+                      filters.remove(exercise);
+                    }
+                  });
+                },
+              );
+            }).toList(),
+          ),
+          const SizedBox(height: 10.0),
+          Text(
+            'Looking for: ${filters.map(
+              (ExerciseFilter e) => e.name).join(', ')}',
+            style: textTheme.labelLarge,
+          ),
+        ],
       ),
     );
   }

examples/api/lib/material/switch/switch.0.dart

@@ -14,6 +14,7 @@ class SwitchApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
+      theme: ThemeData(useMaterial3: true),
       home: Scaffold(
         appBar: AppBar(title: const Text('Switch Sample')),
         body: const Center(

examples/api/lib/material/switch/switch.1.dart

@@ -14,6 +14,7 @@ class SwitchApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
+      theme: ThemeData(useMaterial3: true),
       home: Scaffold(
         appBar: AppBar(title: const Text('Switch Sample')),
         body: const Center(

examples/api/lib/material/switch/switch.2.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flutter code sample for Switch
+// Flutter code sample for [Switch].
 
 import 'package:flutter/material.dart';
 
@@ -14,7 +14,7 @@ class SwitchApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      theme: ThemeData(useMaterial3: true, colorSchemeSeed: const Color(0xff6750a4)),
+      theme: ThemeData(useMaterial3: true),
       home: Scaffold(
         appBar: AppBar(title: const Text('Switch Sample')),
         body: const Center(
@@ -35,15 +35,14 @@ class SwitchExample extends StatefulWidget {
 class _SwitchExampleState extends State<SwitchExample> {
   bool light0 = true;
   bool light1 = true;
-  bool light2 = true;
 
-  final MaterialStateProperty<Icon?> thumbIcon = MaterialStateProperty.resolveWith<Icon?>((Set<MaterialState> states) {
-    // Thumb icon when the switch is selected.
-    if (states.contains(MaterialState.selected)) {
-      return const Icon(Icons.check);
-    }
-    return const Icon(Icons.close);
-  },
+  final MaterialStateProperty<Icon?> thumbIcon = MaterialStateProperty.resolveWith<Icon?>(
+    (Set<MaterialState> states) {
+      if (states.contains(MaterialState.selected)) {
+        return const Icon(Icons.check);
+      }
+      return const Icon(Icons.close);
+    },
   );
 
   @override

examples/api/lib/material/switch/switch.3.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 // Flutter code sample for [Switch].
+
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 

examples/api/test/material/date_picker/show_date_picker.0_test.dart

+// 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 'package:flutter_api_samples/material/date_picker/show_date_picker.0.dart' as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Can show date picker', (WidgetTester tester) async {
+    const String datePickerTitle = 'Select date';
+    const String initialDate = 'Sun, Jul 25';
+
+    await tester.pumpWidget(
+      const example.DatePickerApp(),
+    );
+
+    // The date picker is not shown initially.
+    expect(find.text(datePickerTitle), findsNothing);
+    expect(find.text(initialDate), findsNothing);
+
+    // Tap the button to show the date picker.
+    await tester.tap(find.byType(OutlinedButton));
+    await tester.pumpAndSettle();
+
+    // The initial date is shown.
+    expect(find.text(datePickerTitle), findsOneWidget);
+    expect(find.text(initialDate), findsOneWidget);
+
+    // Tap another date to select it.
+    await tester.tap(find.text('30'));
+    await tester.pumpAndSettle();
+
+    // The selected date is shown.
+    expect(find.text(datePickerTitle), findsOneWidget);
+    expect(find.text('Fri, Jul 30'), findsOneWidget);
+
+    // Tap OK to confirm the selection and close the date picker.
+    await tester.tap(find.text('OK'));
+    await tester.pumpAndSettle();
+
+    // The date picker is closed and the selected date is shown.
+    expect(find.text(datePickerTitle), findsNothing);
+    expect(find.text('Selected: 30/7/2021'), findsOneWidget);
+  });
+}

examples/api/test/material/date_picker/show_date_range_picker.0_test.dart

+// 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 'package:flutter_api_samples/material/date_picker/show_date_range_picker.0.dart' as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Can show date range picker', (WidgetTester tester) async {
+    const String datePickerTitle = 'Select range';
+
+    await tester.pumpWidget(
+      const example.DatePickerApp(),
+    );
+
+    // The date range picker is not shown initially.
+    expect(find.text(datePickerTitle), findsNothing);
+    expect(find.text('Jan 1'), findsNothing);
+    expect(find.text('Jan 5, 2021'), findsNothing);
+
+    // Tap the button to show the date range picker.
+    await tester.tap(find.byType(OutlinedButton));
+    await tester.pumpAndSettle();
+
+    // The date range picker shows initial date range.
+    expect(find.text(datePickerTitle), findsOneWidget);
+    expect(find.text('Jan 1'), findsOneWidget);
+    expect(find.text('Jan 5, 2021'), findsOneWidget);
+
+    // Tap to select new date range.
+    await tester.tap(find.text('18').first);
+    await tester.pumpAndSettle();
+    await tester.tap(find.text('22').first);
+    await tester.pumpAndSettle();
+
+    // The selected date range is shown.
+    expect(find.text(datePickerTitle), findsOneWidget);
+    expect(find.text('Jan 18'), findsOneWidget);
+    expect(find.text('Jan 22, 2021'), findsOneWidget);
+
+    // Tap Save to confirm the selection and close the date range picker.
+    await tester.tap(find.text('Save'));
+    await tester.pumpAndSettle();
+
+    // The date range picker is closed.
+    expect(find.text(datePickerTitle), findsNothing);
+    expect(find.text('Jan 18'), findsNothing);
+    expect(find.text('Jan 22, 2021'), findsNothing);
+  });
+}

examples/api/test/material/switch/switch.2_test.dart

+// 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 'package:flutter_api_samples/material/switch/switch.2.dart' as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Switch thumb icon supports material states', (WidgetTester tester) async {
+    const Set<MaterialState> selected = <MaterialState>{ MaterialState.selected };
+    const Set<MaterialState> unselected = <MaterialState>{};
+
+    await tester.pumpWidget(
+      const example.SwitchApp(),
+    );
+
+    Switch materialSwitch = tester.widget<Switch>(find.byType(Switch).first);
+    expect(materialSwitch.thumbIcon, null);
+
+    materialSwitch = tester.widget<Switch>(find.byType(Switch).last);
+    expect(materialSwitch.thumbIcon, isNotNull);
+    expect(
+      materialSwitch.thumbIcon!.resolve(selected)!.icon,
+      Icons.check,
+    );
+    expect(
+      materialSwitch.thumbIcon!.resolve(unselected)!.icon,
+      Icons.close,
+    );
+  });
+}