Normalize ThemeData.tabBarTheme (#156253)

Following https://github.com/flutter/flutter/pull/155476, this PR is to normalize `ThemeData.tabBarTheme`; change the `TabBarTheme tabBarTheme` property to `TabBarThemeData tabBarTheme` in `ThemeData`. In `ThemeData()` and `ThemeData.copyWith()`, the `tabBarTheme` parameter type is changed to `Object?` to accept both `TabBarTheme` and `TabBarThemeData` so that we won't cause immediate breaking change and make sure rolling is smooth. Once all component themes are normalized, these `Object?` types should be changed to `xxxThemeData`.

There's no way to create a dart fix because we can't add a "@deprecated" label for TabBarTheme; TabBarTheme is a new InheritedWidget subclass now.

Addresses the "theme normalization" sub project within https://github.com/flutter/flutter/issues/91772

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

@@ -245,9 +245,9 @@ class TabBarTheme extends InheritedTheme with Diagnosticable {
   }
 
   /// Returns the closest [TabBarTheme] instance given the build context.
-  static TabBarTheme of(BuildContext context) {
+  static TabBarThemeData of(BuildContext context) {
     final TabBarTheme? tabBarTheme = context.dependOnInheritedWidgetOfExactType<TabBarTheme>();
-    return tabBarTheme ?? Theme.of(context).tabBarTheme;
+    return tabBarTheme?.data ?? Theme.of(context).tabBarTheme;
   }
 
   /// Linearly interpolate between two tab bar themes.

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

@@ -246,7 +246,7 @@ class _TabStyle extends AnimatedWidget {
 
   MaterialStateColor _resolveWithLabelColor(BuildContext context) {
     final ThemeData themeData = Theme.of(context);
-    final TabBarThemeData tabBarTheme = TabBarTheme.of(context).data;
+    final TabBarThemeData tabBarTheme = TabBarTheme.of(context);
     final Animation<double> animation = listenable as Animation<double>;
 
     // labelStyle.color (and tabBarTheme.labelStyle.color) is not considered
@@ -285,7 +285,7 @@ class _TabStyle extends AnimatedWidget {
 
   @override
   Widget build(BuildContext context) {
-    final TabBarThemeData tabBarTheme = TabBarTheme.of(context).data;
+    final TabBarThemeData tabBarTheme = TabBarTheme.of(context);
     final Animation<double> animation = listenable as Animation<double>;
 
     final Set<MaterialState> states = isSelected
@@ -1355,7 +1355,7 @@ class _TabBarState extends State<TabBar> {
 
   Decoration _getIndicator(TabBarIndicatorSize indicatorSize) {
     final ThemeData theme = Theme.of(context);
-    final TabBarThemeData tabBarTheme = TabBarTheme.of(context).data;
+    final TabBarThemeData tabBarTheme = TabBarTheme.of(context);
 
     if (widget.indicator != null) {
       return widget.indicator!;
@@ -1455,7 +1455,7 @@ class _TabBarState extends State<TabBar> {
 
   void _initIndicatorPainter() {
     final ThemeData theme = Theme.of(context);
-    final TabBarTheme tabBarTheme = TabBarTheme.of(context);
+    final TabBarThemeData tabBarTheme = TabBarTheme.of(context);
     final TabBarIndicatorSize indicatorSize = widget.indicatorSize
       ?? tabBarTheme.indicatorSize
       ?? _defaults.indicatorSize!;
@@ -1687,7 +1687,7 @@ class _TabBarState extends State<TabBar> {
     assert(debugCheckHasMaterialLocalizations(context));
     assert(_debugScheduleCheckHasValidTabsCount());
     final ThemeData theme = Theme.of(context);
-    final TabBarThemeData tabBarTheme = TabBarTheme.of(context).data;
+    final TabBarThemeData tabBarTheme = TabBarTheme.of(context);
     final TabAlignment effectiveTabAlignment = widget.tabAlignment ?? tabBarTheme.tabAlignment ?? _defaults.tabAlignment!;
     assert(_debugTabAlignmentIsValid(effectiveTabAlignment));
 

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

@@ -348,7 +348,8 @@ class ThemeData with Diagnosticable {
     SliderThemeData? sliderTheme,
     SnackBarThemeData? snackBarTheme,
     SwitchThemeData? switchTheme,
-    TabBarTheme? tabBarTheme,
+    // TODO(QuncCccccc): Change the parameter type to TabBarThemeData
+    Object? tabBarTheme,
     TextButtonThemeData? textButtonTheme,
     TextSelectionThemeData? textSelectionTheme,
     TimePickerThemeData? timePickerTheme,
@@ -541,7 +542,15 @@ class ThemeData with Diagnosticable {
     sliderTheme ??= const SliderThemeData();
     snackBarTheme ??= const SnackBarThemeData();
     switchTheme ??= const SwitchThemeData();
-    tabBarTheme ??= const TabBarTheme();
+    // TODO(QuncCccccc): Clean this up once the type of `tabBarTheme` is changed to `TabBarThemeData`
+    if (tabBarTheme != null) {
+      if (tabBarTheme is TabBarTheme) {
+        tabBarTheme = tabBarTheme.data;
+      } else if (tabBarTheme is! TabBarThemeData) {
+        throw ArgumentError('tabBarTheme must be either a TabBarThemeData or a TabBarTheme');
+      }
+    }
+    tabBarTheme ??= const TabBarThemeData();
     textButtonTheme ??= const TextButtonThemeData();
     textSelectionTheme ??= const TextSelectionThemeData();
     timePickerTheme ??= const TimePickerThemeData();
@@ -634,7 +643,7 @@ class ThemeData with Diagnosticable {
       sliderTheme: sliderTheme,
       snackBarTheme: snackBarTheme,
       switchTheme: switchTheme,
-      tabBarTheme: tabBarTheme,
+      tabBarTheme: tabBarTheme as TabBarThemeData,
       textButtonTheme: textButtonTheme,
       textSelectionTheme: textSelectionTheme,
       timePickerTheme: timePickerTheme,
@@ -1387,7 +1396,7 @@ class ThemeData with Diagnosticable {
   final SwitchThemeData switchTheme;
 
   /// A theme for customizing the size, shape, and color of the tab bar indicator.
-  final TabBarTheme tabBarTheme;
+  final TabBarThemeData tabBarTheme;
 
   /// A theme for customizing the appearance and internal layout of
   /// [TextButton]s.
@@ -1507,7 +1516,8 @@ class ThemeData with Diagnosticable {
     SliderThemeData? sliderTheme,
     SnackBarThemeData? snackBarTheme,
     SwitchThemeData? switchTheme,
-    TabBarTheme? tabBarTheme,
+    // TODO(QuncCccccc): Change the parameter type to TabBarThemeData
+    Object? tabBarTheme,
     TextButtonThemeData? textButtonTheme,
     TextSelectionThemeData? textSelectionTheme,
     TimePickerThemeData? timePickerTheme,
@@ -1547,6 +1557,15 @@ class ThemeData with Diagnosticable {
         throw ArgumentError('dialogTheme must be either a DialogThemeData or a DialogTheme');
       }
     }
+
+    // TODO(QuncCccccc): Clean this up once the type of `tabBarTheme` is changed to `TabBarThemeData`
+    if (tabBarTheme != null) {
+      if (tabBarTheme is TabBarTheme) {
+        tabBarTheme = tabBarTheme.data;
+      } else if (tabBarTheme is! TabBarThemeData) {
+        throw ArgumentError('tabBarTheme must be either a TabBarThemeData or a TabBarTheme');
+      }
+    }
     return ThemeData.raw(
       // For the sanity of the reader, make sure these properties are in the same
       // order in every place that they are separated by section comments (e.g.
@@ -1634,7 +1653,7 @@ class ThemeData with Diagnosticable {
       sliderTheme: sliderTheme ?? this.sliderTheme,
       snackBarTheme: snackBarTheme ?? this.snackBarTheme,
       switchTheme: switchTheme ?? this.switchTheme,
-      tabBarTheme: tabBarTheme ?? this.tabBarTheme,
+      tabBarTheme: tabBarTheme as TabBarThemeData? ?? this.tabBarTheme,
       textButtonTheme: textButtonTheme ?? this.textButtonTheme,
       textSelectionTheme: textSelectionTheme ?? this.textSelectionTheme,
       timePickerTheme: timePickerTheme ?? this.timePickerTheme,
@@ -1827,7 +1846,7 @@ class ThemeData with Diagnosticable {
       sliderTheme: SliderThemeData.lerp(a.sliderTheme, b.sliderTheme, t),
       snackBarTheme: SnackBarThemeData.lerp(a.snackBarTheme, b.snackBarTheme, t),
       switchTheme: SwitchThemeData.lerp(a.switchTheme, b.switchTheme, t),
-      tabBarTheme: TabBarTheme.lerp(a.tabBarTheme, b.tabBarTheme, t),
+      tabBarTheme: TabBarThemeData.lerp(a.tabBarTheme, b.tabBarTheme, t),
       textButtonTheme: TextButtonThemeData.lerp(a.textButtonTheme, b.textButtonTheme, t)!,
       textSelectionTheme: TextSelectionThemeData.lerp(a.textSelectionTheme, b.textSelectionTheme, t)!,
       timePickerTheme: TimePickerThemeData.lerp(a.timePickerTheme, b.timePickerTheme, t),
@@ -2125,7 +2144,7 @@ class ThemeData with Diagnosticable {
     properties.add(DiagnosticsProperty<SliderThemeData>('sliderTheme', sliderTheme, level: DiagnosticLevel.debug));
     properties.add(DiagnosticsProperty<SnackBarThemeData>('snackBarTheme', snackBarTheme, defaultValue: defaultData.snackBarTheme, level: DiagnosticLevel.debug));
     properties.add(DiagnosticsProperty<SwitchThemeData>('switchTheme', switchTheme, defaultValue: defaultData.switchTheme, level: DiagnosticLevel.debug));
-    properties.add(DiagnosticsProperty<TabBarTheme>('tabBarTheme', tabBarTheme, level: DiagnosticLevel.debug));
+    properties.add(DiagnosticsProperty<TabBarThemeData>('tabBarTheme', tabBarTheme, level: DiagnosticLevel.debug));
     properties.add(DiagnosticsProperty<TextButtonThemeData>('textButtonTheme', textButtonTheme, defaultValue: defaultData.textButtonTheme, level: DiagnosticLevel.debug));
     properties.add(DiagnosticsProperty<TextSelectionThemeData>('textSelectionTheme', textSelectionTheme, defaultValue: defaultData.textSelectionTheme, level: DiagnosticLevel.debug));
     properties.add(DiagnosticsProperty<TimePickerThemeData>('timePickerTheme', timePickerTheme, defaultValue: defaultData.timePickerTheme, level: DiagnosticLevel.debug));

packages/flutter/test/material/tab_bar_theme_test.dart

@@ -36,7 +36,7 @@ final List<SizedBox> _sizedTabs = <SizedBox>[
 
 Widget buildTabBar({
   TabBarThemeData? localTabBarTheme,
-  TabBarTheme? tabBarTheme,
+  TabBarThemeData? tabBarTheme,
   bool secondaryTabBar = false,
   List<Widget> tabs = _tabs,
   bool isScrollable = false,
@@ -316,7 +316,7 @@ void main() {
 
   testWidgets('Tab bar theme overrides label color (selected)', (WidgetTester tester) async {
     const Color labelColor = Colors.black;
-    const TabBarTheme tabBarTheme = TabBarTheme(labelColor: labelColor);
+    const TabBarThemeData tabBarTheme = TabBarThemeData(labelColor: labelColor);
 
     await tester.pumpWidget(buildTabBar(tabBarTheme: tabBarTheme));
 
@@ -337,7 +337,7 @@ void main() {
       leftPadding, topPadding, rightPadding, bottomPadding,
     );
 
-    const TabBarTheme tabBarTheme = TabBarTheme(labelPadding: labelPadding);
+    const TabBarThemeData tabBarTheme = TabBarThemeData(labelPadding: labelPadding);
 
     await tester.pumpWidget(buildTabBar(
       tabBarTheme: tabBarTheme,
@@ -366,7 +366,7 @@ void main() {
   testWidgets('Tab bar theme overrides label styles', (WidgetTester tester) async {
     const TextStyle labelStyle = TextStyle(fontFamily: 'foobar');
     const TextStyle unselectedLabelStyle = TextStyle(fontFamily: 'baz');
-    const TabBarTheme tabBarTheme = TabBarTheme(
+    const TabBarThemeData tabBarTheme = TabBarThemeData(
       labelStyle: labelStyle,
       unselectedLabelStyle: unselectedLabelStyle,
     );
@@ -382,7 +382,7 @@ void main() {
   testWidgets('Tab bar theme with just label style specified', (WidgetTester tester) async {
     // Regression test for https://github.com/flutter/flutter/issues/28784
     const TextStyle labelStyle = TextStyle(fontFamily: 'foobar');
-    const TabBarTheme tabBarTheme = TabBarTheme(
+    const TabBarThemeData tabBarTheme = TabBarThemeData(
       labelStyle: labelStyle,
     );
 
@@ -401,7 +401,7 @@ void main() {
     const TextStyle unselectedLabelStyle = TextStyle(fontFamily: '2');
     const TextStyle themeLabelStyle = TextStyle(fontFamily: '3');
     const TextStyle themeUnselectedLabelStyle = TextStyle(fontFamily: '4');
-    const TabBarTheme tabBarTheme = TabBarTheme(
+    const TabBarThemeData tabBarTheme = TabBarThemeData(
       labelStyle: themeLabelStyle,
       unselectedLabelStyle: themeUnselectedLabelStyle,
     );
@@ -448,7 +448,7 @@ void main() {
 
     const double indicatorWeight = 2.0; // default value
 
-    const TabBarTheme tabBarTheme = TabBarTheme(labelPadding: themeLabelPadding);
+    const TabBarThemeData tabBarTheme = TabBarThemeData(labelPadding: themeLabelPadding);
 
     final TabController controller = TabController(
       length: _sizedTabs.length,
@@ -509,7 +509,7 @@ void main() {
 
     const double indicatorWeight = 2.0; // default value
 
-    const TabBarTheme tabBarTheme = TabBarTheme(labelPadding: themeLabelPadding);
+    const TabBarThemeData tabBarTheme = TabBarThemeData(labelPadding: themeLabelPadding);
 
     final TabController controller = TabController(
       length: _sizedTabs.length,
@@ -554,7 +554,7 @@ void main() {
 
   testWidgets('Tab bar theme overrides label color (unselected)', (WidgetTester tester) async {
     const Color unselectedLabelColor = Colors.black;
-    const TabBarTheme tabBarTheme = TabBarTheme(unselectedLabelColor: unselectedLabelColor);
+    const TabBarThemeData tabBarTheme = TabBarThemeData(unselectedLabelColor: unselectedLabelColor);
 
     await tester.pumpWidget(buildTabBar(tabBarTheme: tabBarTheme));
 
@@ -583,7 +583,7 @@ void main() {
   });
 
   testWidgets('Tab bar theme overrides tab indicator size (tab)', (WidgetTester tester) async {
-    const TabBarTheme tabBarTheme = TabBarTheme(indicatorSize: TabBarIndicatorSize.tab);
+    const TabBarThemeData tabBarTheme = TabBarThemeData(indicatorSize: TabBarIndicatorSize.tab);
 
     await tester.pumpWidget(buildTabBar(tabBarTheme: tabBarTheme));
 
@@ -594,7 +594,7 @@ void main() {
   });
 
   testWidgets('Tab bar theme overrides tab indicator size (label)', (WidgetTester tester) async {
-    const TabBarTheme tabBarTheme = TabBarTheme(indicatorSize: TabBarIndicatorSize.label);
+    const TabBarThemeData tabBarTheme = TabBarThemeData(indicatorSize: TabBarIndicatorSize.label);
 
     await tester.pumpWidget(buildTabBar(tabBarTheme: tabBarTheme));
 
@@ -605,7 +605,7 @@ void main() {
   });
 
   testWidgets('Tab bar theme overrides tab mouse cursor', (WidgetTester tester) async {
-    const TabBarTheme tabBarTheme = TabBarTheme(mouseCursor: MaterialStateMouseCursor.textable);
+    const TabBarThemeData tabBarTheme = TabBarThemeData(mouseCursor: MaterialStateMouseCursor.textable);
 
     await tester.pumpWidget(buildTabBar(tabBarTheme: tabBarTheme));
 
@@ -620,7 +620,7 @@ void main() {
   });
 
   testWidgets('Tab bar theme - custom tab indicator', (WidgetTester tester) async {
-    final TabBarTheme tabBarTheme = TabBarTheme(
+    final TabBarThemeData tabBarTheme = TabBarThemeData(
       indicator: BoxDecoration(
         border: Border.all(),
       ),
@@ -635,7 +635,7 @@ void main() {
   });
 
   testWidgets('Tab bar theme - beveled rect indicator', (WidgetTester tester) async {
-    const TabBarTheme tabBarTheme = TabBarTheme(
+    const TabBarThemeData tabBarTheme = TabBarThemeData(
       indicator: ShapeDecoration(
         shape: BeveledRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(20.0))),
         color: Colors.black,
@@ -651,7 +651,7 @@ void main() {
   });
 
   testWidgets('TabAlignment.fill from TabBarTheme only supports non-scrollable tab bar', (WidgetTester tester) async {
-    const TabBarTheme tabBarTheme = TabBarTheme(tabAlignment: TabAlignment.fill);
+    const TabBarThemeData tabBarTheme = TabBarThemeData(tabAlignment: TabAlignment.fill);
 
     // Test TabAlignment.fill from TabBarTheme with non-scrollable tab bar.
     await tester.pumpWidget(buildTabBar(tabBarTheme: tabBarTheme));
@@ -667,7 +667,7 @@ void main() {
   testWidgets(
     'TabAlignment.start & TabAlignment.startOffset from TabBarTheme only supports scrollable tab bar',
     (WidgetTester tester) async {
-      TabBarTheme tabBarTheme = const TabBarTheme(tabAlignment: TabAlignment.start);
+      TabBarThemeData tabBarTheme = const TabBarThemeData(tabAlignment: TabAlignment.start);
 
       // Test TabAlignment.start from TabBarTheme with scrollable tab bar.
       await tester.pumpWidget(buildTabBar(tabBarTheme: tabBarTheme, isScrollable: true));
@@ -679,7 +679,7 @@ void main() {
 
       expect(tester.takeException(), isAssertionError);
 
-      tabBarTheme = const TabBarTheme(tabAlignment: TabAlignment.startOffset);
+      tabBarTheme = const TabBarThemeData(tabAlignment: TabAlignment.startOffset);
 
       // Test TabAlignment.startOffset from TabBarTheme with scrollable tab bar.
       await tester.pumpWidget(buildTabBar(tabBarTheme: tabBarTheme, isScrollable: true));
@@ -694,7 +694,7 @@ void main() {
 
   testWidgets('TabBarTheme.indicatorSize provides correct tab indicator (primary)', (WidgetTester tester) async {
     final ThemeData theme = ThemeData(
-      tabBarTheme: const TabBarTheme(indicatorSize: TabBarIndicatorSize.tab),
+      tabBarTheme: const TabBarThemeData(indicatorSize: TabBarIndicatorSize.tab),
       useMaterial3: true,
     );
     final List<Widget> tabs = List<Widget>.generate(4, (int index) {
@@ -750,7 +750,7 @@ void main() {
 
   testWidgets('TabBarTheme.indicatorSize provides correct tab indicator (secondary)', (WidgetTester tester) async {
     final ThemeData theme = ThemeData(
-      tabBarTheme: const TabBarTheme(indicatorSize: TabBarIndicatorSize.label),
+      tabBarTheme: const TabBarThemeData(indicatorSize: TabBarIndicatorSize.label),
       useMaterial3: true,
     );
     final List<Widget> tabs = List<Widget>.generate(4, (int index) {
@@ -815,7 +815,7 @@ void main() {
     await tester.pumpWidget(
       MaterialApp(
         theme: ThemeData(
-          tabBarTheme: const TabBarTheme(
+          tabBarTheme: const TabBarThemeData(
             dividerColor: dividerColor,
             dividerHeight: dividerHeight,
           ),
@@ -855,7 +855,7 @@ void main() {
       MaterialApp(
         theme: ThemeData(
           useMaterial3: true,
-          tabBarTheme: const TabBarTheme(
+          tabBarTheme: const TabBarThemeData(
             dividerColor: Colors.pink,
             dividerHeight: 5.0,
           ),
@@ -893,7 +893,7 @@ void main() {
     await tester.pumpWidget(
       MaterialApp(
         theme: ThemeData(
-          tabBarTheme: const TabBarTheme(tabAlignment: TabAlignment.center),
+          tabBarTheme: const TabBarThemeData(tabAlignment: TabAlignment.center),
           useMaterial3: true,
         ),
         home: Scaffold(
@@ -929,7 +929,7 @@ void main() {
     await tester.pumpWidget(
       MaterialApp(
         theme: ThemeData(
-          tabBarTheme: const TabBarTheme(tabAlignment: TabAlignment.start),
+          tabBarTheme: const TabBarThemeData(tabAlignment: TabAlignment.start),
           useMaterial3: true,
         ),
         home: Scaffold(
@@ -968,7 +968,7 @@ void main() {
     await tester.pumpWidget(
       MaterialApp(
         theme: ThemeData(
-          tabBarTheme: const TabBarTheme(tabAlignment: TabAlignment.fill),
+          tabBarTheme: const TabBarThemeData(tabAlignment: TabAlignment.fill),
           useMaterial3: true,
         ),
         home: Scaffold(
@@ -1005,7 +1005,7 @@ void main() {
     await tester.pumpWidget(
       MaterialApp(
         theme: ThemeData(
-          tabBarTheme: const TabBarTheme(tabAlignment: TabAlignment.center),
+          tabBarTheme: const TabBarThemeData(tabAlignment: TabAlignment.center),
           useMaterial3: true,
         ),
         home: Scaffold(
@@ -1045,7 +1045,7 @@ void main() {
         color: Color(0x950000ff),
         fontStyle: FontStyle.italic,
       );
-      const TabBarTheme tabBarTheme = TabBarTheme(
+      const TabBarThemeData tabBarTheme = TabBarThemeData(
         labelStyle: labelStyle,
         unselectedLabelStyle: unselectedLabelStyle,
       );
@@ -1082,7 +1082,7 @@ void main() {
         color: Color(0x950000ff),
         fontStyle: FontStyle.italic,
       );
-      TabBarTheme tabBarTheme = const TabBarTheme(
+      TabBarThemeData tabBarTheme = const TabBarThemeData(
         labelStyle: labelStyle,
         unselectedLabelStyle: unselectedLabelStyle,
       );
@@ -1109,7 +1109,7 @@ void main() {
       expect(unselectedTextStyle.fontStyle, unselectedLabelStyle.fontStyle);
 
       // Update the TabBarTheme with labelColor & unselectedLabelColor.
-      tabBarTheme = const TabBarTheme(
+      tabBarTheme = const TabBarThemeData(
         labelColor: labelColor,
         unselectedLabelColor: unselectedLabelColor,
         labelStyle: labelStyle,
@@ -1147,7 +1147,7 @@ void main() {
         fontStyle: FontStyle.italic,
       );
 
-      Widget buildTabBar({TabBarTheme? tabBarTheme}) {
+      Widget buildTabBar({TabBarThemeData? tabBarTheme}) {
         return MaterialApp(
           theme: ThemeData(tabBarTheme: tabBarTheme),
           home: const Material(
@@ -1186,7 +1186,7 @@ void main() {
       expect(unselectedTextStyle.fontStyle, unselectedLabelStyle.fontStyle);
 
       // Add TabBarTheme with labelColor & unselectedLabelColor.
-      await tester.pumpWidget(buildTabBar(tabBarTheme: const TabBarTheme(
+      await tester.pumpWidget(buildTabBar(tabBarTheme: const TabBarThemeData(
         labelColor: labelColor,
         unselectedLabelColor: unselectedLabelColor,
       )));
@@ -1303,7 +1303,7 @@ void main() {
 
     testWidgets('TabBarTheme.indicatorSize provides correct tab indicator (primary)', (WidgetTester tester) async {
       final ThemeData theme = ThemeData(
-        tabBarTheme: const TabBarTheme(indicatorSize: TabBarIndicatorSize.tab),
+        tabBarTheme: const TabBarThemeData(indicatorSize: TabBarIndicatorSize.tab),
         useMaterial3: false,
       );
       final List<Widget> tabs = List<Widget>.generate(4, (int index) {
@@ -1354,7 +1354,7 @@ void main() {
 
     testWidgets('TabBarTheme.indicatorSize provides correct tab indicator (secondary)', (WidgetTester tester) async {
       final ThemeData theme = ThemeData(
-        tabBarTheme: const TabBarTheme(indicatorSize: TabBarIndicatorSize.label),
+        tabBarTheme: const TabBarThemeData(indicatorSize: TabBarIndicatorSize.label),
         useMaterial3: false,
       );
       final List<Widget> tabs = List<Widget>.generate(4, (int index) {
@@ -1412,7 +1412,7 @@ void main() {
       await tester.pumpWidget(
         MaterialApp(
           theme: ThemeData(
-            tabBarTheme: const TabBarTheme(tabAlignment: TabAlignment.center),
+            tabBarTheme: const TabBarThemeData(tabAlignment: TabAlignment.center),
             useMaterial3: false,
           ),
           home: Scaffold(
@@ -1449,7 +1449,7 @@ void main() {
       await tester.pumpWidget(
         MaterialApp(
           theme: ThemeData(
-            tabBarTheme: const TabBarTheme(tabAlignment: TabAlignment.fill),
+            tabBarTheme: const TabBarThemeData(tabAlignment: TabAlignment.fill),
             useMaterial3: false,
           ),
           home: Scaffold(
@@ -1512,7 +1512,7 @@ void main() {
 
     await tester.pumpWidget(buildTabBar(theme: ThemeData(
       useMaterial3: true,
-      tabBarTheme: const TabBarTheme(indicatorColor: tabBarThemeIndicatorColor)
+      tabBarTheme: const TabBarThemeData(indicatorColor: tabBarThemeIndicatorColor)
     )));
     await tester.pumpAndSettle();
 
@@ -1538,7 +1538,7 @@ void main() {
       return MaterialApp(
         theme: ThemeData(
           indicatorColor: themeIndicatorColor,
-          tabBarTheme: TabBarTheme(indicatorColor: tabBarThemeIndicatorColor),
+          tabBarTheme: TabBarThemeData(indicatorColor: tabBarThemeIndicatorColor),
           useMaterial3: false,
         ),
         home: Material(
@@ -1575,7 +1575,7 @@ void main() {
       return unselectedColor;
     });
 
-    final TabBarTheme tabBarTheme = TabBarTheme(labelColor: labelColor);
+    final TabBarThemeData tabBarTheme = TabBarThemeData(labelColor: labelColor);
 
     // Test labelColor correctly resolves material states.
     await tester.pumpWidget(buildTabBar(tabBarTheme: tabBarTheme));
@@ -1604,7 +1604,7 @@ void main() {
       const Color selectedColor = Color(0xff00ffff);
       const Color unselectedColor = Color(0xffff12ff);
 
-      TabBarTheme tabBarTheme = TabBarTheme(labelColor: labelColor);
+      TabBarThemeData tabBarTheme = TabBarThemeData(labelColor: labelColor);
 
       // Test material state label color.
       await tester.pumpWidget(buildTabBar(tabBarTheme: tabBarTheme));
@@ -1620,7 +1620,7 @@ void main() {
       expect(unselectedTextStyle.color, unselectedStateColor);
 
       // Test labelColor & unselectedLabelColor override material state labelColor.
-      tabBarTheme = const TabBarTheme(
+      tabBarTheme = const TabBarThemeData(
         labelColor: selectedColor,
         unselectedLabelColor: unselectedColor,
       );
@@ -1644,7 +1644,7 @@ void main() {
     Widget buildTabs({ TextScaler? textScaler }) {
       return MaterialApp(
         theme: ThemeData(
-          tabBarTheme: TabBarTheme(
+          tabBarTheme: TabBarThemeData(
             textScaler: textScaler,
           ),
         ),
@@ -1699,7 +1699,7 @@ void main() {
     Widget buildTab({ TabIndicatorAnimation? indicatorAnimation }) {
       return MaterialApp(
         theme: ThemeData(
-          tabBarTheme: TabBarTheme(
+          tabBarTheme: TabBarThemeData(
             indicatorAnimation: indicatorAnimation,
           ),
         ),

packages/flutter/test/material/tabs_test.dart

@@ -20,7 +20,7 @@ Widget boilerplate({
   Widget? child,
   TextDirection textDirection = TextDirection.ltr,
   ThemeData? theme,
-  TabBarTheme? tabBarTheme,
+  TabBarThemeData? tabBarTheme,
   bool? useMaterial3,
 }) {
   return Theme(
@@ -52,7 +52,7 @@ Widget buildFrame({
   EdgeInsetsGeometry? padding,
   TextDirection textDirection = TextDirection.ltr,
   TabAlignment? tabAlignment,
-  TabBarTheme? tabBarTheme,
+  TabBarThemeData? tabBarTheme,
   Decoration? indicator,
   bool? useMaterial3,
 }) {
@@ -5536,7 +5536,7 @@ void main() {
     await tester.pumpWidget(
       MaterialApp(
         theme: ThemeData(
-          tabBarTheme: const TabBarTheme(labelPadding: labelPadding),
+          tabBarTheme: const TabBarThemeData(labelPadding: labelPadding),
         ),
         home: Scaffold(
           appBar: AppBar(
@@ -5857,7 +5857,7 @@ void main() {
     await tester.pumpWidget(
       MaterialApp(
         theme: ThemeData.light().copyWith(
-          tabBarTheme: TabBarTheme(
+          tabBarTheme: TabBarThemeData(
             splashFactory: splashFactory,
             overlayColor: overlayColor,
           )),
@@ -6554,7 +6554,7 @@ void main() {
       MaterialApp(
         theme: ThemeData(
           useMaterial3: true,
-          tabBarTheme: const TabBarTheme(dividerColor: dividerColor),
+          tabBarTheme: const TabBarThemeData(dividerColor: dividerColor),
         ),
         home: Scaffold(
           appBar: AppBar(
@@ -6583,7 +6583,7 @@ void main() {
       MaterialApp(
         theme: ThemeData(
           useMaterial3: true,
-          tabBarTheme: const TabBarTheme(dividerColor: dividerColor),
+          tabBarTheme: const TabBarThemeData(dividerColor: dividerColor),
         ),
         home: Scaffold(
           body: DefaultTabController(
@@ -6835,7 +6835,7 @@ void main() {
       const String unSelectedValue = 'C';
       const Color labelColor = Color(0xff0000ff);
       await tester.pumpWidget(
-        buildFrame(tabs: tabs, value: selectedValue, useMaterial3: false, tabBarTheme: const TabBarTheme(labelColor: labelColor)),
+        buildFrame(tabs: tabs, value: selectedValue, useMaterial3: false, tabBarTheme: const TabBarThemeData(labelColor: labelColor)),
       );
       expect(find.text('A'), findsOneWidget);
       expect(find.text('B'), findsOneWidget);

packages/flutter/test/material/theme_data_test.dart

@@ -919,7 +919,7 @@ void main() {
       sliderTheme: sliderTheme,
       snackBarTheme: const SnackBarThemeData(backgroundColor: Colors.black),
       switchTheme: const SwitchThemeData(),
-      tabBarTheme: const TabBarTheme(labelColor: Colors.black),
+      tabBarTheme: const TabBarThemeData(labelColor: Colors.black),
       textButtonTheme: TextButtonThemeData(style: TextButton.styleFrom(foregroundColor: Colors.red)),
       textSelectionTheme: const TextSelectionThemeData(cursorColor: Colors.black),
       timePickerTheme: const TimePickerThemeData(backgroundColor: Colors.black),
@@ -1033,7 +1033,7 @@ void main() {
       sliderTheme: otherSliderTheme,
       snackBarTheme: const SnackBarThemeData(backgroundColor: Colors.white),
       switchTheme: const SwitchThemeData(),
-      tabBarTheme: const TabBarTheme(labelColor: Colors.white),
+      tabBarTheme: const TabBarThemeData(labelColor: Colors.white),
       textButtonTheme: const TextButtonThemeData(),
       textSelectionTheme: const TextSelectionThemeData(cursorColor: Colors.white),
       timePickerTheme: const TimePickerThemeData(backgroundColor: Colors.white),