TextField should support disabled input text style (flutter#119216)

Co-authored-by: Renzo Olivares <roliv@google.com>

Author: Renzo-Olivares

dev/tools/gen_defaults/lib/text_field_template.dart

@@ -9,6 +9,13 @@ class TextFieldTemplate extends TokenTemplate {
 
   @override
   String generate() => '''
+TextStyle? _m3StateInputStyle(BuildContext context) => MaterialStateTextStyle.resolveWith((Set<MaterialState> states) {
+  if (states.contains(MaterialState.disabled)) {
+    return TextStyle(color: ${textStyle("md.comp.filled-text-field.label-text")}!.color?.withOpacity(0.38));
+  }
+  return TextStyle(color: ${textStyle("md.comp.filled-text-field.label-text")}!.color);
+});
+
 TextStyle _m3InputStyle(BuildContext context) => ${textStyle("md.comp.filled-text-field.label-text")}!;
 
 TextStyle _m3CounterErrorStyle(BuildContext context) =>

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

@@ -11,6 +11,7 @@ import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
 
 import 'adaptive_text_selection_toolbar.dart';
+import 'color_scheme.dart';
 import 'colors.dart';
 import 'debug.dart';
 import 'desktop_text_selection.dart';
@@ -1191,6 +1192,22 @@ class _TextFieldState extends State<TextField> with RestorationMixin implements
   }
   // AutofillClient implementation end.
 
+  Set<MaterialState> get _materialState {
+    return <MaterialState>{
+      if (!_isEnabled) MaterialState.disabled,
+      if (_isHovering) MaterialState.hovered,
+      if (_effectiveFocusNode.hasFocus) MaterialState.focused,
+      if (_hasError) MaterialState.error,
+    };
+  }
+
+  TextStyle _getInputStyleForState(TextStyle style) {
+    final ThemeData theme = Theme.of(context);
+    final TextStyle stateStyle = MaterialStateProperty.resolveAs(theme.useMaterial3 ? _m3StateInputStyle(context)! : _m2StateInputStyle(context)!, _materialState);
+    final TextStyle providedStyle = MaterialStateProperty.resolveAs(style, _materialState);
+    return providedStyle.merge(stateStyle);
+  }
+
   @override
   Widget build(BuildContext context) {
     assert(debugCheckHasMaterial(context));
@@ -1204,7 +1221,7 @@ class _TextFieldState extends State<TextField> with RestorationMixin implements
 
     final ThemeData theme = Theme.of(context);
     final DefaultSelectionStyle selectionStyle = DefaultSelectionStyle.of(context);
-    final TextStyle style = (theme.useMaterial3 ? _m3InputStyle(context) : theme.textTheme.titleMedium!).merge(widget.style);
+    final TextStyle style = _getInputStyleForState(theme.useMaterial3 ? _m3InputStyle(context) : theme.textTheme.titleMedium!).merge(widget.style);
     final Brightness keyboardAppearance = widget.keyboardAppearance ?? theme.brightness;
     final TextEditingController controller = _effectiveController;
     final FocusNode focusNode = _effectiveFocusNode;
@@ -1402,12 +1419,7 @@ class _TextFieldState extends State<TextField> with RestorationMixin implements
     }
     final MouseCursor effectiveMouseCursor = MaterialStateProperty.resolveAs<MouseCursor>(
       widget.mouseCursor ?? MaterialStateMouseCursor.textable,
-      <MaterialState>{
-        if (!_isEnabled) MaterialState.disabled,
-        if (_isHovering) MaterialState.hovered,
-        if (focusNode.hasFocus) MaterialState.focused,
-        if (_hasError) MaterialState.error,
-      },
+      _materialState,
     );
 
     final int? semanticsMaxValueLength;
@@ -1453,6 +1465,14 @@ class _TextFieldState extends State<TextField> with RestorationMixin implements
   }
 }
 
+TextStyle? _m2StateInputStyle(BuildContext context) => MaterialStateTextStyle.resolveWith((Set<MaterialState> states) {
+  final ThemeData theme = Theme.of(context);
+  if (states.contains(MaterialState.disabled)) {
+    return TextStyle(color: theme.disabledColor);
+  }
+  return TextStyle(color: theme.textTheme.titleMedium?.color);
+});
+
 TextStyle _m2CounterErrorStyle(BuildContext context) =>
   Theme.of(context).textTheme.bodySmall!.copyWith(color: Theme.of(context).colorScheme.error);
 
@@ -1465,6 +1485,13 @@ TextStyle _m2CounterErrorStyle(BuildContext context) =>
 
 // Token database version: v0_162
 
+TextStyle? _m3StateInputStyle(BuildContext context) => MaterialStateTextStyle.resolveWith((Set<MaterialState> states) {
+  if (states.contains(MaterialState.disabled)) {
+    return TextStyle(color: Theme.of(context).textTheme.bodyLarge!.color?.withOpacity(0.38));
+  }
+  return TextStyle(color: Theme.of(context).textTheme.bodyLarge!.color);
+});
+
 TextStyle _m3InputStyle(BuildContext context) => Theme.of(context).textTheme.bodyLarge!;
 
 TextStyle _m3CounterErrorStyle(BuildContext context) =>

packages/flutter/test/material/text_field_test.dart

@@ -6071,6 +6071,51 @@ void main() {
     expect(errorWidget.style!.color, equals(Colors.transparent));
   });
 
+  testWidgets('Disabled text field has default M2 disabled text style for the input text', (WidgetTester tester) async {
+    final TextEditingController controller = TextEditingController(
+      text: 'Atwater Peel Sherbrooke Bonaventure',
+    );
+
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Material(
+          child: Center(
+            child: TextField(
+              controller: controller,
+              enabled: false,
+            ),
+          ),
+        ),
+      ),
+    );
+    final EditableText editableText = tester.widget(find.byType(EditableText));
+    expect(editableText.style.color, Colors.black38); // Colors.black38 is the default disabled color for ThemeData.light().
+  });
+
+  testWidgets('Disabled text field has default M3 disabled text style for the input text', (WidgetTester tester) async {
+    final TextEditingController controller = TextEditingController(
+      text: 'Atwater Peel Sherbrooke Bonaventure',
+    );
+
+    final ThemeData theme = ThemeData.light(useMaterial3: true);
+
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: theme,
+        home: Material(
+          child: Center(
+            child: TextField(
+              controller: controller,
+              enabled: false,
+            ),
+          ),
+        ),
+      ),
+    );
+    final EditableText editableText = tester.widget(find.byType(EditableText));
+    expect(editableText.style.color, theme.textTheme.bodyLarge!.color!.withOpacity(0.38));
+  });
+
   testWidgets('currentValueLength/maxValueLength are in the tree', (WidgetTester tester) async {
     final SemanticsTester semantics = SemanticsTester(tester);
     final TextEditingController controller = TextEditingController();
@@ -8355,7 +8400,11 @@ void main() {
     // Empty TextStyle is overridden by theme
     await tester.pumpWidget(buildFrame(const TextStyle()));
     EditableText editableText = tester.widget(find.byType(EditableText));
+
+    // According to material 3 spec, the input text should be the color of onSurface.
+    // https://github.com/flutter/flutter/issues/107686 is tracking this issue.
     expect(editableText.style.color, themeData.textTheme.bodyLarge!.color);
+
     expect(editableText.style.background, themeData.textTheme.bodyLarge!.background);
     expect(editableText.style.shadows, themeData.textTheme.bodyLarge!.shadows);
     expect(editableText.style.decoration, themeData.textTheme.bodyLarge!.decoration);