Revert "Update `ExpansionTile` to support Material 3 & add an example (#119712)" (#120300)

This reverts commit e8eac0d0.

dev/tools/gen_defaults/bin/gen_defaults.dart

@@ -31,7 +31,6 @@ import 'package:gen_defaults/date_picker_template.dart';
 import 'package:gen_defaults/dialog_template.dart';
 import 'package:gen_defaults/divider_template.dart';
 import 'package:gen_defaults/drawer_template.dart';
-import 'package:gen_defaults/expansion_tile_template.dart';
 import 'package:gen_defaults/fab_template.dart';
 import 'package:gen_defaults/filter_chip_template.dart';
 import 'package:gen_defaults/icon_button_template.dart';
@@ -154,7 +153,6 @@ Future<void> main(List<String> args) async {
   DialogTemplate('Dialog', '$materialLib/dialog.dart', tokens).updateFile();
   DividerTemplate('Divider', '$materialLib/divider.dart', tokens).updateFile();
   DrawerTemplate('Drawer', '$materialLib/drawer.dart', tokens).updateFile();
-  ExpansionTileTemplate('ExpansionTile', '$materialLib/expansion_tile.dart', tokens).updateFile();
   FABTemplate('FAB', '$materialLib/floating_action_button.dart', tokens).updateFile();
   FilterChipTemplate('ChoiceChip', '$materialLib/choice_chip.dart', tokens).updateFile();
   FilterChipTemplate('FilterChip', '$materialLib/filter_chip.dart', tokens).updateFile();

dev/tools/gen_defaults/lib/expansion_tile_template.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 'template.dart';
-
-class ExpansionTileTemplate extends TokenTemplate {
-  const ExpansionTileTemplate(super.blockName, super.fileName, super.tokens, {
-    super.colorSchemePrefix = '_colors.',
-  });
-
-  @override
-  String generate() => '''
-class _${blockName}DefaultsM3 extends ExpansionTileThemeData {
-  _${blockName}DefaultsM3(this.context);
-
-  final BuildContext context;
-  late final ThemeData _theme = Theme.of(context);
-  late final ColorScheme _colors = _theme.colorScheme;
-
-  @override
-  Color? get textColor => ${textStyle("md.comp.list.list-item.label-text")}!.color;
-
-  @override
-  Color? get iconColor => ${componentColor('md.comp.list.list-item.selected.trailing-icon')};
-
-  @override
-  Color? get collapsedTextColor => ${textStyle("md.comp.list.list-item.label-text")}!.color;
-
-  @override
-  Color? get collapsedIconColor => ${componentColor('md.comp.list.list-item.unselected.trailing-icon')};
-}
-''';
-}

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

@@ -6,31 +6,33 @@
 
 import 'package:flutter/material.dart';
 
-void main() => runApp(const ExpansionTileApp());
+void main() => runApp(const MyApp());
 
-class ExpansionTileApp extends StatelessWidget {
-  const ExpansionTileApp({super.key});
+class MyApp extends StatelessWidget {
+  const MyApp({super.key});
+
+  static const String _title = 'Flutter Code Sample';
 
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      theme: ThemeData(useMaterial3: true),
+      title: _title,
       home: Scaffold(
-        appBar: AppBar(title: const Text('ExpansionTile Sample')),
-        body: const ExpansionTileExample(),
+        appBar: AppBar(title: const Text(_title)),
+        body: const MyStatefulWidget(),
       ),
     );
   }
 }
 
-class ExpansionTileExample extends StatefulWidget {
-  const ExpansionTileExample({super.key});
+class MyStatefulWidget extends StatefulWidget {
+  const MyStatefulWidget({super.key});
 
   @override
-  State<ExpansionTileExample> createState() => _ExpansionTileExampleState();
+  State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
 }
 
-class _ExpansionTileExampleState extends State<ExpansionTileExample> {
+class _MyStatefulWidgetState extends State<MyStatefulWidget> {
   bool _customTileExpanded = false;
 
   @override
@@ -56,9 +58,7 @@ class _ExpansionTileExampleState extends State<ExpansionTileExample> {
             ListTile(title: Text('This is tile number 2')),
           ],
           onExpansionChanged: (bool expanded) {
-            setState(() {
-              _customTileExpanded = expanded;
-            });
+            setState(() => _customTileExpanded = expanded);
           },
         ),
         const ExpansionTile(

examples/api/test/material/expansion_tile/expansion_tile.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/expansion_tile/expansion_tile.0.dart' as example;
-import 'package:flutter_test/flutter_test.dart';
-
-void main() {
-  testWidgets('When expansion tiles are expanded tile numbers are revealed', (WidgetTester tester) async {
-    const int totalTiles = 3;
-
-    await tester.pumpWidget(
-      const example.ExpansionTileApp(),
-    );
-
-    expect(find.byType(ExpansionTile), findsNWidgets(totalTiles));
-
-    const String tileOne = 'This is tile number 1';
-    expect(find.text(tileOne), findsNothing);
-
-    await tester.tap(find.text('ExpansionTile 1'));
-    await tester.pumpAndSettle();
-    expect(find.text(tileOne), findsOneWidget);
-
-    const String tileTwo = 'This is tile number 2';
-    expect(find.text(tileTwo), findsNothing);
-
-    await tester.tap(find.text('ExpansionTile 2'));
-    await tester.pumpAndSettle();
-    expect(find.text(tileTwo), findsOneWidget);
-
-    const String tileThree = 'This is tile number 3';
-    expect(find.text(tileThree), findsNothing);
-
-    await tester.tap(find.text('ExpansionTile 3'));
-    await tester.pumpAndSettle();
-    expect(find.text(tileThree), findsOneWidget);
-  });
-}

packages/flutter/lib/src/material/expansion_tile.dart

@@ -34,8 +34,7 @@ const Duration _kExpand = Duration(milliseconds: 200);
 /// to the [leading] and [trailing] properties of [ExpansionTile].
 ///
 /// {@tool dartpad}
-/// This example demonstrates how the [ExpansionTile] icon's location and appearance
-/// can be customized.
+/// This example demonstrates different configurations of ExpansionTile.
 ///
 /// ** See code in examples/api/lib/material/expansion_tile/expansion_tile.0.dart **
 /// {@end-tool}
@@ -217,7 +216,7 @@ class ExpansionTile extends StatefulWidget {
   /// Used to override to the [ListTileThemeData.iconColor].
   ///
   /// If this property is null then [ExpansionTileThemeData.iconColor] is used. If that
-  /// is also null then the value of [ColorScheme.primary] is used.
+  /// is also null then the value of [ListTileThemeData.iconColor] is used.
   ///
   /// See also:
   ///
@@ -228,15 +227,6 @@ class ExpansionTile extends StatefulWidget {
   /// The icon color of tile's expansion arrow icon when the sublist is collapsed.
   ///
   /// Used to override to the [ListTileThemeData.iconColor].
-  ///
-  /// If this property is null then [ExpansionTileThemeData.collapsedIconColor] is used. If that
-  /// is also null and [ThemeData.useMaterial3] is true, [ColorScheme.onSurface] is used. Otherwise,
-  /// defaults to [ThemeData.unselectedWidgetColor] color.
-  ///
-  /// See also:
-  ///
-  /// * [ExpansionTileTheme.of], which returns the nearest [ExpansionTileTheme]'s
-  ///   [ExpansionTileThemeData].
   final Color? collapsedIconColor;
 
 
@@ -245,8 +235,7 @@ class ExpansionTile extends StatefulWidget {
   /// Used to override to the [ListTileThemeData.textColor].
   ///
   /// If this property is null then [ExpansionTileThemeData.textColor] is used. If that
-  /// is also null then and [ThemeData.useMaterial3] is true, color of the [TextTheme.bodyLarge]
-  /// will be used for the [title] and [subtitle]. Otherwise, defaults to [ColorScheme.primary] color.
+  /// is also null then the value of [ListTileThemeData.textColor] is used.
   ///
   /// See also:
   ///
@@ -258,10 +247,8 @@ class ExpansionTile extends StatefulWidget {
   ///
   /// Used to override to the [ListTileThemeData.textColor].
   ///
-  /// If this property is null then [ExpansionTileThemeData.collapsedTextColor] is used.
-  /// If that is also null and [ThemeData.useMaterial3] is true, color of the
-  /// [TextTheme.bodyLarge] will be used for the [title] and [subtitle]. Otherwise,
-  /// defaults to color of the [TextTheme.titleMedium].
+  /// If this property is null then [ExpansionTileThemeData.collapsedTextColor] is used. If that
+  /// is also null then the value of [ListTileThemeData.textColor] is used.
   ///
   /// See also:
   ///
@@ -454,9 +441,7 @@ class _ExpansionTileState extends State<ExpansionTile> with SingleTickerProvider
   void didChangeDependencies() {
     final ThemeData theme = Theme.of(context);
     final ExpansionTileThemeData expansionTileTheme = ExpansionTileTheme.of(context);
-    final ExpansionTileThemeData defaults = theme.useMaterial3
-      ? _ExpansionTileDefaultsM3(context)
-      : _ExpansionTileDefaultsM2(context);
+    final ColorScheme colorScheme = theme.colorScheme;
     _borderTween
       ..begin = widget.collapsedShape
         ?? expansionTileTheme.collapsedShape
@@ -473,13 +458,13 @@ class _ExpansionTileState extends State<ExpansionTile> with SingleTickerProvider
     _headerColorTween
       ..begin = widget.collapsedTextColor
         ?? expansionTileTheme.collapsedTextColor
-        ?? defaults.collapsedTextColor
-      ..end = widget.textColor ?? expansionTileTheme.textColor ?? defaults.textColor;
+        ?? theme.textTheme.titleMedium!.color
+      ..end = widget.textColor ?? expansionTileTheme.textColor ?? colorScheme.primary;
     _iconColorTween
       ..begin = widget.collapsedIconColor
         ?? expansionTileTheme.collapsedIconColor
-        ?? defaults.collapsedIconColor
-      ..end = widget.iconColor ?? expansionTileTheme.iconColor ?? defaults.iconColor;
+        ?? theme.unselectedWidgetColor
+      ..end = widget.iconColor ?? expansionTileTheme.iconColor ?? colorScheme.primary;
     _backgroundColorTween
       ..begin = widget.collapsedBackgroundColor ?? expansionTileTheme.collapsedBackgroundColor
       ..end = widget.backgroundColor ?? expansionTileTheme.backgroundColor;
@@ -513,54 +498,3 @@ class _ExpansionTileState extends State<ExpansionTile> with SingleTickerProvider
     );
   }
 }
-
-class _ExpansionTileDefaultsM2 extends ExpansionTileThemeData {
-  _ExpansionTileDefaultsM2(this.context);
-
-  final BuildContext context;
-  late final ThemeData _theme = Theme.of(context);
-  late final ColorScheme _colorScheme = _theme.colorScheme;
-
-  @override
-  Color? get textColor => _colorScheme.primary;
-
-  @override
-  Color? get iconColor => _colorScheme.primary;
-
-  @override
-  Color? get collapsedTextColor => _theme.textTheme.titleMedium!.color;
-
-  @override
-  Color? get collapsedIconColor => _theme.unselectedWidgetColor;
-}
-
-// BEGIN GENERATED TOKEN PROPERTIES - ExpansionTile
-
-// Do not edit by hand. The code between the "BEGIN GENERATED" and
-// "END GENERATED" comments are generated from data in the Material
-// Design token database by the script:
-//   dev/tools/gen_defaults/bin/gen_defaults.dart.
-
-// Token database version: v0_152
-
-class _ExpansionTileDefaultsM3 extends ExpansionTileThemeData {
-  _ExpansionTileDefaultsM3(this.context);
-
-  final BuildContext context;
-  late final ThemeData _theme = Theme.of(context);
-  late final ColorScheme _colors = _theme.colorScheme;
-
-  @override
-  Color? get textColor => Theme.of(context).textTheme.bodyLarge!.color;
-
-  @override
-  Color? get iconColor => _colors.primary;
-
-  @override
-  Color? get collapsedTextColor => Theme.of(context).textTheme.bodyLarge!.color;
-
-  @override
-  Color? get collapsedIconColor => _colors.onSurface;
-}
-
-// END GENERATED TOKEN PROPERTIES - ExpansionTile

packages/flutter/test/material/expansion_tile_test.dart

@@ -522,35 +522,6 @@ void main() {
     expect(shapeDecoration.color, backgroundColor);
   });
 
-  testWidgets('ExpansionTile default iconColor, textColor', (WidgetTester tester) async {
-    final ThemeData theme = ThemeData(useMaterial3: true);
-
-    await tester.pumpWidget(MaterialApp(
-      theme: theme,
-      home: const Material(
-        child: ExpansionTile(
-          title: TestText('title'),
-          trailing: TestIcon(),
-          children: <Widget>[
-            SizedBox(height: 100, width: 100),
-          ],
-        ),
-      ),
-    ));
-
-    Color getIconColor() => tester.state<TestIconState>(find.byType(TestIcon)).iconTheme.color!;
-    Color getTextColor() => tester.state<TestTextState>(find.byType(TestText)).textStyle.color!;
-
-    expect(getIconColor(), theme.colorScheme.onSurface);
-    expect(getTextColor(), theme.textTheme.bodyLarge!.color);
-
-    await tester.tap(find.text('title'));
-    await tester.pumpAndSettle();
-
-    expect(getIconColor(), theme.colorScheme.primary);
-    expect(getTextColor(), theme.textTheme.bodyLarge!.color);
-  });
-
   testWidgets('ExpansionTile iconColor, textColor', (WidgetTester tester) async {
     // Regression test for https://github.com/flutter/flutter/pull/78281
 
@@ -695,38 +666,4 @@ void main() {
     expect(listTile.leading.runtimeType, Icon);
     expect(listTile.trailing, isNull);
   });
-
-  group('Material 2', () {
-    // Tests that are only relevant for Material 2. Once ThemeData.useMaterial3
-    // is turned on by default, these tests can be removed.
-
-    testWidgets('ExpansionTile default iconColor, textColor', (WidgetTester tester) async {
-      final ThemeData theme = ThemeData(useMaterial3: false);
-
-      await tester.pumpWidget(MaterialApp(
-        theme: theme,
-        home: const Material(
-          child: ExpansionTile(
-            title: TestText('title'),
-            trailing: TestIcon(),
-            children: <Widget>[
-              SizedBox(height: 100, width: 100),
-            ],
-          ),
-        ),
-      ));
-
-      Color getIconColor() => tester.state<TestIconState>(find.byType(TestIcon)).iconTheme.color!;
-      Color getTextColor() => tester.state<TestTextState>(find.byType(TestText)).textStyle.color!;
-
-      expect(getIconColor(), theme.unselectedWidgetColor);
-      expect(getTextColor(), theme.textTheme.titleMedium!.color);
-
-      await tester.tap(find.text('title'));
-      await tester.pumpAndSettle();
-
-      expect(getIconColor(), theme.colorScheme.primary);
-      expect(getTextColor(), theme.colorScheme.primary);
-    });
-  });
 }