Updated the M3 textTheme to use `onSurface` color for all styles. (#116125)

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

@@ -565,7 +565,9 @@ class ThemeData with Diagnosticable {
     splashColor ??= isDark ? _kDarkThemeSplashColor : _kLightThemeSplashColor;
 
     // TYPOGRAPHY & ICONOGRAPHY
-    typography ??= useMaterial3 ? Typography.material2021(platform: platform) : Typography.material2014(platform: platform);
+    typography ??= useMaterial3
+      ? Typography.material2021(platform: platform, colorScheme: colorScheme)
+      : Typography.material2014(platform: platform);
     TextTheme defaultTextTheme = isDark ? typography.white : typography.black;
     TextTheme defaultPrimaryTextTheme = primaryIsDark ? typography.white : typography.black;
     TextTheme defaultAccentTextTheme = accentIsDark ? typography.white : typography.black;

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

@@ -5,6 +5,7 @@
 import 'package:flutter/foundation.dart';
 import 'package:flutter/painting.dart';
 
+import 'color_scheme.dart';
 import 'colors.dart';
 import 'text_theme.dart';
 
@@ -166,6 +167,7 @@ class Typography with Diagnosticable {
   ///  * <https://m3.material.io/styles/typography>
   factory Typography.material2021({
     TargetPlatform? platform = TargetPlatform.android,
+    ColorScheme colorScheme = const ColorScheme.light(),
     TextTheme? black,
     TextTheme? white,
     TextTheme? englishLike,
@@ -173,13 +175,31 @@ class Typography with Diagnosticable {
     TextTheme? tall,
   }) {
     assert(platform != null || (black != null && white != null));
-    return Typography._withPlatform(
+    final Typography base = Typography._withPlatform(
       platform,
       black, white,
       englishLike ?? englishLike2021,
       dense ?? dense2021,
       tall ?? tall2021,
     );
+
+    // Ensure they are all uniformly dark or light, with
+    // no color variation based on style as it was in previous
+    // versions of Material Design.
+    final Color dark = colorScheme.brightness == Brightness.light ? colorScheme.onSurface : colorScheme.surface;
+    final Color light = colorScheme.brightness == Brightness.light ? colorScheme.surface : colorScheme.onSurface;
+    return base.copyWith(
+      black: base.black.apply(
+        displayColor: dark,
+        bodyColor: dark,
+        decorationColor: dark
+      ),
+      white: base.white.apply(
+        displayColor: light,
+        bodyColor: light,
+        decorationColor: light
+      ),
+    );
   }
 
   factory Typography._withPlatform(

packages/flutter/test/material/banner_theme_test.dart

@@ -67,11 +67,16 @@ void main() {
   });
 
   testWidgets('Passing no MaterialBannerThemeData returns defaults', (WidgetTester tester) async {
-    final ThemeData theme = ThemeData(useMaterial3: true);
     const String contentText = 'Content';
+    final ThemeData theme = ThemeData(useMaterial3: true);
+    late final ThemeData localizedTheme;
 
     await tester.pumpWidget(MaterialApp(
       theme: theme,
+      builder:(BuildContext context, Widget? child) {
+        localizedTheme = Theme.of(context);
+        return child!;
+      },
       home: Scaffold(
         body: MaterialBanner(
           content: const Text(contentText),
@@ -93,12 +98,9 @@ void main() {
     expect(material.elevation, 0.0);
 
     final RenderParagraph content = _getTextRenderObjectFromDialog(tester, contentText);
-    // Default value for ThemeData.typography is Typography.material2021()
     expect(
       content.text.style,
-      Typography.material2021().englishLike.bodyMedium!.merge(
-        Typography.material2021().black.bodyMedium,
-      ),
+      localizedTheme.textTheme.bodyMedium,
     );
 
     final Offset rowTopLeft = tester.getTopLeft(find.byType(Row));
@@ -114,15 +116,17 @@ void main() {
   });
 
   testWidgets('Passing no MaterialBannerThemeData returns defaults when presented by ScaffoldMessenger', (WidgetTester tester) async {
-    final ThemeData theme = ThemeData(useMaterial3: true);
     const String contentText = 'Content';
     const Key tapTarget = Key('tap-target');
+    final ThemeData theme = ThemeData(useMaterial3: true);
+    late final ThemeData localizedTheme;
 
     await tester.pumpWidget(MaterialApp(
       theme: theme,
       home: Scaffold(
         body: Builder(
           builder: (BuildContext context) {
+            localizedTheme = Theme.of(context);
             return GestureDetector(
               key: tapTarget,
               onTap: () {
@@ -157,12 +161,9 @@ void main() {
     expect(material.elevation, 0.0);
 
     final RenderParagraph content = _getTextRenderObjectFromDialog(tester, contentText);
-    // Default value for ThemeData.typography is Typography.material2021()
     expect(
       content.text.style,
-      Typography.material2021().englishLike.bodyMedium!.merge(
-        Typography.material2021().black.bodyMedium,
-      ),
+      localizedTheme.textTheme.bodyMedium,
     );
 
     final Offset rowTopLeft = tester.getTopLeft(find.byType(Row));

packages/flutter/test/material/list_tile_test.dart

@@ -2230,7 +2230,7 @@ void main() {
       );
     }
 
-    final ThemeData theme = ThemeData();
+    final ThemeData theme = ThemeData(useMaterial3: true);
 
     // ListTile - ListTileStyle.list (default).
     await tester.pumpWidget(buildFrame());

packages/flutter/test/material/theme_data_test.dart

@@ -72,15 +72,15 @@ void main() {
   test('light, dark and fallback constructors support useMaterial3', () {
     final ThemeData lightTheme = ThemeData.light(useMaterial3: true);
     expect(lightTheme.useMaterial3, true);
-    expect(lightTheme.typography, Typography.material2021());
+    expect(lightTheme.typography, Typography.material2021(colorScheme: lightTheme.colorScheme));
 
     final ThemeData darkTheme = ThemeData.dark(useMaterial3: true);
     expect(darkTheme.useMaterial3, true);
-    expect(darkTheme.typography, Typography.material2021());
+    expect(darkTheme.typography, Typography.material2021(colorScheme: darkTheme.colorScheme));
 
     final ThemeData fallbackTheme = ThemeData.light(useMaterial3: true);
     expect(fallbackTheme.useMaterial3, true);
-    expect(fallbackTheme.typography, Typography.material2021());
+    expect(fallbackTheme.typography, Typography.material2021(colorScheme: fallbackTheme.colorScheme));
   });
 
   testWidgets('Defaults to MaterialTapTargetBehavior.padded on mobile platforms and MaterialTapTargetBehavior.shrinkWrap on desktop', (WidgetTester tester) async {

packages/flutter/test/material/theme_test.dart

@@ -134,7 +134,8 @@ void main() {
 
   testWidgets('ThemeData with null typography uses proper defaults', (WidgetTester tester) async {
     expect(ThemeData().typography, Typography.material2014());
-    expect(ThemeData(useMaterial3: true).typography, Typography.material2021());
+    final ThemeData m3Theme = ThemeData(useMaterial3: true);
+    expect(m3Theme.typography, Typography.material2021(colorScheme: m3Theme.colorScheme));
   });
 
   testWidgets('PopupMenu inherits shadowed app theme', (WidgetTester tester) async {

packages/flutter/test/material/typography_test.dart

@@ -363,4 +363,46 @@ void main() {
     expect(theme.bodySmall!.textBaseline, TextBaseline.alphabetic);
     expect(theme.bodySmall!.leadingDistribution, TextLeadingDistribution.even);
   });
+
+  test('Default M3 light textTheme styles all use onSurface', () {
+    final ThemeData theme = ThemeData(useMaterial3: true);
+    final TextTheme textTheme = theme.textTheme;
+    final Color dark = theme.colorScheme.onSurface;
+    expect(textTheme.displayLarge!.color, dark);
+    expect(textTheme.displayMedium!.color, dark);
+    expect(textTheme.displaySmall!.color, dark);
+    expect(textTheme.headlineLarge!.color, dark);
+    expect(textTheme.headlineMedium!.color, dark);
+    expect(textTheme.headlineSmall!.color, dark);
+    expect(textTheme.titleLarge!.color, dark);
+    expect(textTheme.titleMedium!.color, dark);
+    expect(textTheme.titleSmall!.color, dark);
+    expect(textTheme.bodyLarge!.color, dark);
+    expect(textTheme.bodyMedium!.color, dark);
+    expect(textTheme.bodySmall!.color, dark);
+    expect(textTheme.labelLarge!.color, dark);
+    expect(textTheme.labelMedium!.color, dark);
+    expect(textTheme.labelSmall!.color, dark);
+  });
+
+  test('Default M3 dark textTheme styles all use onSurface', () {
+    final ThemeData theme = ThemeData(useMaterial3: true, brightness: Brightness.dark);
+    final TextTheme textTheme = theme.textTheme;
+    final Color light = theme.colorScheme.onSurface;
+    expect(textTheme.displayLarge!.color, light);
+    expect(textTheme.displayMedium!.color, light);
+    expect(textTheme.displaySmall!.color, light);
+    expect(textTheme.headlineLarge!.color, light);
+    expect(textTheme.headlineMedium!.color, light);
+    expect(textTheme.headlineSmall!.color, light);
+    expect(textTheme.titleLarge!.color, light);
+    expect(textTheme.titleMedium!.color, light);
+    expect(textTheme.titleSmall!.color, light);
+    expect(textTheme.bodyLarge!.color, light);
+    expect(textTheme.bodyMedium!.color, light);
+    expect(textTheme.bodySmall!.color, light);
+    expect(textTheme.labelLarge!.color, light);
+    expect(textTheme.labelMedium!.color, light);
+    expect(textTheme.labelSmall!.color, light);
+  });
 }