TextSelectionTheme support (step 1 of 3) (#62014)

Create a new TextSelectionTheme for text selection properties.

packages/flutter/lib/material.dart

@@ -129,6 +129,7 @@ export 'src/material/text_button_theme.dart';
 export 'src/material/text_field.dart';
 export 'src/material/text_form_field.dart';
 export 'src/material/text_selection.dart';
+export 'src/material/text_selection_theme.dart';
 export 'src/material/text_theme.dart';
 export 'src/material/theme.dart';
 export 'src/material/theme_data.dart';

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

@@ -13,6 +13,7 @@ import 'package:flutter/gestures.dart';
 
 import 'feedback.dart';
 import 'text_selection.dart';
+import 'text_selection_theme.dart';
 import 'theme.dart';
 
 /// An eyeballed value that moves the cursor slightly left of where it is
@@ -584,7 +585,8 @@ class _SelectableTextState extends State<SelectableText> with AutomaticKeepAlive
       'inherit false style must supply fontSize and textBaseline',
     );
 
-    final ThemeData themeData = Theme.of(context);
+    final ThemeData theme = Theme.of(context);
+    final TextSelectionThemeData selectionTheme = TextSelectionTheme.of(context);
     final FocusNode focusNode = _effectiveFocusNode;
 
     TextSelectionControls textSelectionControls;
@@ -592,16 +594,23 @@ class _SelectableTextState extends State<SelectableText> with AutomaticKeepAlive
     bool cursorOpacityAnimates;
     Offset cursorOffset;
     Color cursorColor = widget.cursorColor;
+    Color selectionColor;
     Radius cursorRadius = widget.cursorRadius;
 
-    switch (themeData.platform) {
+    switch (theme.platform) {
       case TargetPlatform.iOS:
       case TargetPlatform.macOS:
         forcePressEnabled = true;
         textSelectionControls = cupertinoTextSelectionControls;
         paintCursorAboveText = true;
         cursorOpacityAnimates = true;
-        cursorColor ??= CupertinoTheme.of(context).primaryColor;
+        if (theme.useTextSelectionTheme) {
+          cursorColor ??= selectionTheme.cursorColor ?? CupertinoTheme.of(context).primaryColor;
+          selectionColor = selectionTheme.selectionColor ?? CupertinoTheme.of(context).primaryColor;
+        } else {
+          cursorColor ??= CupertinoTheme.of(context).primaryColor;
+          selectionColor = theme.textSelectionColor;
+        }
         cursorRadius ??= const Radius.circular(2.0);
         cursorOffset = Offset(iOSHorizontalOffset / MediaQuery.of(context).devicePixelRatio, 0);
         break;
@@ -614,7 +623,13 @@ class _SelectableTextState extends State<SelectableText> with AutomaticKeepAlive
         textSelectionControls = materialTextSelectionControls;
         paintCursorAboveText = false;
         cursorOpacityAnimates = false;
-        cursorColor ??= themeData.cursorColor;
+        if (theme.useTextSelectionTheme) {
+          cursorColor ??= selectionTheme.cursorColor ?? theme.colorScheme.primary;
+          selectionColor = selectionTheme.selectionColor ?? theme.colorScheme.primary;
+        } else {
+          cursorColor ??= theme.cursorColor;
+          selectionColor = theme.textSelectionColor;
+        }
         break;
     }
 
@@ -644,7 +659,7 @@ class _SelectableTextState extends State<SelectableText> with AutomaticKeepAlive
         toolbarOptions: widget.toolbarOptions,
         minLines: widget.minLines,
         maxLines: widget.maxLines ?? defaultTextStyle.maxLines,
-        selectionColor: themeData.textSelectionColor,
+        selectionColor: selectionColor,
         selectionControls: widget.selectionEnabled ? textSelectionControls : null,
         onSelectionChanged: _handleSelectionChanged,
         onSelectionHandleTapped: _handleSelectionHandleTapped,

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

@@ -22,6 +22,7 @@ import 'material_localizations.dart';
 import 'material_state.dart';
 import 'selectable_text.dart' show iOSHorizontalOffset;
 import 'text_selection.dart';
+import 'text_selection_theme.dart';
 import 'theme.dart';
 
 export 'package:flutter/services.dart' show TextInputType, TextInputAction, TextCapitalization, SmartQuotesType, SmartDashesType;
@@ -637,10 +638,22 @@ class TextField extends StatefulWidget {
   /// {@macro flutter.widgets.editableText.cursorRadius}
   final Radius cursorRadius;
 
-  /// The color to use when painting the cursor.
+  /// The color of the cursor.
   ///
-  /// Defaults to [ThemeData.cursorColor] or [CupertinoThemeData.primaryColor]
-  /// depending on [ThemeData.platform].
+  /// The cursor indicates the current location of text insertion point in
+  /// the field.
+  ///
+  /// If this is null it will default to a value based on the following:
+  ///
+  /// * If the ambient [ThemeData.useTextSelectionTheme] is true then it
+  ///   will use the value of the ambient [TextSelectionThemeData.cursorColor].
+  ///   If that is null then if the [ThemeData.platform] is [TargetPlatform.iOS]
+  ///   or [TargetPlatform.macOS] then it will use [CupertinoThemeData.primaryColor].
+  ///   Otherwise it will use the value of [ColorScheme.primary] of [ThemeData.colorScheme].
+  ///
+  /// * If the ambient [ThemeData.useTextSelectionTheme] is false then it
+  ///   will use either [ThemeData.cursorColor] or [CupertinoThemeData.primaryColor]
+  ///   depending on [ThemeData.platform].
   final Color cursorColor;
 
   /// Controls how tall the selection highlight boxes are computed to be.
@@ -1017,6 +1030,11 @@ class _TextFieldState extends State<TextField> implements TextSelectionGestureDe
     }
   }
 
+  Color _defaultSelectionColor(BuildContext context, Color primary) {
+    final bool isDark = Theme.of(context).brightness == Brightness.dark;
+    return primary.withOpacity(isDark ? 0.40 : 0.12);
+  }
+
   @override
   Widget build(BuildContext context) {
     assert(debugCheckHasMaterial(context));
@@ -1028,9 +1046,10 @@ class _TextFieldState extends State<TextField> implements TextSelectionGestureDe
       'inherit false style must supply fontSize and textBaseline',
     );
 
-    final ThemeData themeData = Theme.of(context);
-    final TextStyle style = themeData.textTheme.subtitle1.merge(widget.style);
-    final Brightness keyboardAppearance = widget.keyboardAppearance ?? themeData.primaryColorBrightness;
+    final ThemeData theme = Theme.of(context);
+    final TextSelectionThemeData selectionTheme = TextSelectionTheme.of(context);
+    final TextStyle style = theme.textTheme.subtitle1.merge(widget.style);
+    final Brightness keyboardAppearance = widget.keyboardAppearance ?? theme.primaryColorBrightness;
     final TextEditingController controller = _effectiveController;
     final FocusNode focusNode = _effectiveFocusNode;
     final List<TextInputFormatter> formatters = widget.inputFormatters ?? <TextInputFormatter>[];
@@ -1042,20 +1061,27 @@ class _TextFieldState extends State<TextField> implements TextSelectionGestureDe
     bool cursorOpacityAnimates;
     Offset cursorOffset;
     Color cursorColor = widget.cursorColor;
+    Color selectionColor;
     Color autocorrectionTextRectColor;
     Radius cursorRadius = widget.cursorRadius;
 
-    switch (themeData.platform) {
+    switch (theme.platform) {
       case TargetPlatform.iOS:
       case TargetPlatform.macOS:
         forcePressEnabled = true;
         textSelectionControls = cupertinoTextSelectionControls;
         paintCursorAboveText = true;
         cursorOpacityAnimates = true;
-        cursorColor ??= CupertinoTheme.of(context).primaryColor;
+        if (theme.useTextSelectionTheme) {
+          cursorColor ??= selectionTheme.cursorColor ?? CupertinoTheme.of(context).primaryColor;
+          selectionColor = selectionTheme.selectionColor ?? _defaultSelectionColor(context, CupertinoTheme.of(context).primaryColor);
+        } else {
+          cursorColor ??= CupertinoTheme.of(context).primaryColor;
+          selectionColor = theme.textSelectionColor;
+        }
         cursorRadius ??= const Radius.circular(2.0);
         cursorOffset = Offset(iOSHorizontalOffset / MediaQuery.of(context).devicePixelRatio, 0);
-        autocorrectionTextRectColor = themeData.textSelectionColor;
+        autocorrectionTextRectColor = selectionColor;
         break;
 
       case TargetPlatform.android:
@@ -1066,7 +1092,13 @@ class _TextFieldState extends State<TextField> implements TextSelectionGestureDe
         textSelectionControls = materialTextSelectionControls;
         paintCursorAboveText = false;
         cursorOpacityAnimates = false;
-        cursorColor ??= themeData.cursorColor;
+        if (theme.useTextSelectionTheme) {
+          cursorColor ??= selectionTheme.cursorColor ?? theme.colorScheme.primary;
+          selectionColor = selectionTheme.selectionColor ?? _defaultSelectionColor(context, theme.colorScheme.primary);
+        } else {
+          cursorColor ??= theme.cursorColor;
+          selectionColor = theme.textSelectionColor;
+        }
         break;
     }
 
@@ -1096,7 +1128,7 @@ class _TextFieldState extends State<TextField> implements TextSelectionGestureDe
         maxLines: widget.maxLines,
         minLines: widget.minLines,
         expands: widget.expands,
-        selectionColor: themeData.textSelectionColor,
+        selectionColor: selectionColor,
         selectionControls: widget.selectionEnabled ? textSelectionControls : null,
         onChanged: widget.onChanged,
         onSelectionChanged: _handleSelectionChanged,

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

@@ -20,6 +20,7 @@ import 'icon_button.dart';
 import 'icons.dart';
 import 'material.dart';
 import 'material_localizations.dart';
+import 'text_selection_theme.dart';
 import 'theme.dart';
 
 const double _kHandleSize = 22.0;
@@ -795,12 +796,16 @@ class _MaterialTextSelectionControls extends TextSelectionControls {
   /// Builder for material-style text selection handles.
   @override
   Widget buildHandle(BuildContext context, TextSelectionHandleType type, double textHeight) {
+    final ThemeData theme = Theme.of(context);
+    final Color handleColor = theme.useTextSelectionTheme ?
+      TextSelectionTheme.of(context).selectionHandleColor ?? theme.colorScheme.primary :
+      theme.textSelectionHandleColor;
     final Widget handle = SizedBox(
       width: _kHandleSize,
       height: _kHandleSize,
       child: CustomPaint(
         painter: _TextSelectionHandlePainter(
-          color: Theme.of(context).textSelectionHandleColor,
+          color: handleColor,
         ),
       ),
     );

packages/flutter/lib/src/material/text_selection_theme.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.
+
+// @dart = 2.8
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/widgets.dart';
+
+import 'theme.dart';
+
+/// Defines the visual properties needed for text selection in [TextField] and
+/// [SelectableText] widgets.
+///
+/// Used by [TextSelectionTheme] to control the visual properties of text
+/// selection in a widget subtree.
+///
+/// Use [TextSelectionTheme.of] to access the closest ancestor
+/// [TextSelectionTheme] of the current [BuildContext].
+///
+/// See also:
+///
+///  * [TextSelectionTheme], an [InheritedWidget] that propagates the theme down its
+///    subtree.
+///  * [InputDecorationTheme], which defines most other visual properties of
+///    text fields.
+@immutable
+class TextSelectionThemeData with Diagnosticable {
+  /// Creates the set of properties used to configure [TextField]s.
+  const TextSelectionThemeData({
+    this.cursorColor,
+    this.selectionColor,
+    this.selectionHandleColor,
+  });
+
+  /// The color of the cursor in the text field.
+  ///
+  /// The cursor indicates the current location of text insertion point in
+  /// the field.
+  final Color cursorColor;
+
+  /// The background color of selected text.
+  final Color selectionColor;
+
+  /// The color of the selection handles on the text field.
+  ///
+  /// Selection handles are used to indicate the bounds of the selected text,
+  /// or as a handle to drag the cursor to a new location in the text.
+  final Color selectionHandleColor;
+
+  /// Creates a copy of this object with the given fields replaced with the
+  /// specified values.
+  TextSelectionThemeData copyWith({
+    Color cursorColor,
+    Color selectionColor,
+    Color selectionHandleColor,
+  }) {
+    return TextSelectionThemeData(
+      cursorColor: cursorColor ?? this.cursorColor,
+      selectionColor: selectionColor ?? this.selectionColor,
+      selectionHandleColor: selectionHandleColor ?? this.selectionHandleColor,
+    );
+  }
+
+  /// Linearly interpolate between two text field themes.
+  ///
+  /// If both arguments are null, then null is returned.
+  ///
+  /// {@macro dart.ui.shadow.lerp}
+  static TextSelectionThemeData lerp(TextSelectionThemeData a, TextSelectionThemeData b, double t) {
+    if (a == null && b == null)
+      return null;
+    assert(t != null);
+    return TextSelectionThemeData(
+      cursorColor: Color.lerp(a?.cursorColor, b?.cursorColor, t),
+      selectionColor: Color.lerp(a?.selectionColor, b?.selectionColor, t),
+      selectionHandleColor: Color.lerp(a?.selectionHandleColor, b?.selectionHandleColor, t),
+    );
+  }
+
+  @override
+  int get hashCode {
+    return hashValues(
+      cursorColor,
+      selectionColor,
+      selectionHandleColor,
+    );
+  }
+
+  @override
+  bool operator==(Object other) {
+    if (identical(this, other))
+      return true;
+    if (other.runtimeType != runtimeType)
+      return false;
+    return other is TextSelectionThemeData
+      && other.cursorColor == cursorColor
+      && other.selectionColor == selectionColor
+      && other.selectionHandleColor == selectionHandleColor;
+  }
+
+  @override
+  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+    super.debugFillProperties(properties);
+    properties.add(ColorProperty('cursorColor', cursorColor, defaultValue: null));
+    properties.add(ColorProperty('selectionColor', selectionColor, defaultValue: null));
+    properties.add(ColorProperty('selectionHandleColor', selectionHandleColor, defaultValue: null));
+  }
+}
+
+/// An inherited widget that defines the appearance of text selection in
+/// this widget's subtree.
+///
+/// Values specified here are used for [TextField] and [SelectableText]
+/// properties that are not given an explicit non-null value.
+///
+/// {@tool snippet}
+///
+/// Here is an example of a text selection theme that applies a blue cursor
+/// color with light blue selection handles to the child text field.
+///
+/// ```dart
+/// TextSelectionTheme(
+///   data: TextSelectionThemeData(
+///     cursorColor: Colors.blue,
+///     selectionHandleColor: Colors.lightBlue,
+///   ),
+///   child: TextField(),
+/// ),
+/// ```
+/// {@end-tool}
+class TextSelectionTheme extends InheritedTheme {
+  /// Creates a text selection theme widget that specifies the text
+  /// selection properties for all widgets below it in the widget tree.
+  ///
+  /// The data argument must not be null.
+  const TextSelectionTheme({
+    Key key,
+    @required this.data,
+    Widget child,
+  }) : assert(data != null), super(key: key, child: child);
+
+  /// The properties for descendant [TextField] and [SelectableText] widgets.
+  final TextSelectionThemeData data;
+
+  /// Returns the [data] from the closest [TextSelectionTheme] ancestor. If
+  /// there is no ancestor, it returns [ThemeData.textSelectionTheme].
+  /// Applications can assume that the returned value will not be null.
+  ///
+  /// Typical usage is as follows:
+  ///
+  /// ```dart
+  /// TextSelectionThemeData theme = TextSelectionTheme.of(context);
+  /// ```
+  static TextSelectionThemeData of(BuildContext context) {
+    final TextSelectionTheme selectionTheme = context.dependOnInheritedWidgetOfExactType<TextSelectionTheme>();
+    return selectionTheme?.data ?? Theme.of(context).textSelectionTheme;
+  }
+
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final TextSelectionTheme ancestorTheme = context.findAncestorWidgetOfExactType<TextSelectionTheme>();
+    return identical(this, ancestorTheme) ? child : TextSelectionTheme(data: data, child: child);
+  }
+
+  @override
+  bool updateShouldNotify(TextSelectionTheme oldWidget) => data != oldWidget.data;
+}

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

@@ -37,6 +37,7 @@ import 'slider_theme.dart';
 import 'snack_bar_theme.dart';
 import 'tab_bar_theme.dart';
 import 'text_button_theme.dart';
+import 'text_selection_theme.dart';
 import 'text_theme.dart';
 import 'time_picker_theme.dart';
 import 'toggle_buttons_theme.dart';
@@ -281,7 +282,9 @@ class ThemeData with Diagnosticable {
     TextButtonThemeData textButtonTheme,
     ElevatedButtonThemeData elevatedButtonTheme,
     OutlinedButtonThemeData outlinedButtonTheme,
+    TextSelectionThemeData textSelectionTheme,
     bool fixTextFieldOutlineLabel,
+    bool useTextSelectionTheme,
   }) {
     assert(colorScheme?.brightness == null || brightness == null || colorScheme.brightness == brightness);
     final Brightness _brightness = brightness ?? colorScheme?.brightness ?? Brightness.light;
@@ -322,7 +325,6 @@ class ThemeData with Diagnosticable {
     // Spec doesn't specify a dark theme secondaryHeaderColor, this is a guess.
     secondaryHeaderColor ??= isDark ? Colors.grey[700] : primarySwatch[50];
     textSelectionColor ??= isDark ? accentColor : primarySwatch[200];
-    // TODO(hansmuller): We need a TextFieldTheme to handle this instead, https://github.com/flutter/flutter/issues/56082
     cursorColor = cursorColor ?? const Color.fromRGBO(66, 133, 244, 1.0);
     textSelectionHandleColor ??= isDark ? Colors.tealAccent[400] : primarySwatch[300];
     backgroundColor ??= isDark ? Colors.grey[700] : primarySwatch[200];
@@ -397,7 +399,10 @@ class ThemeData with Diagnosticable {
     textButtonTheme ??= const TextButtonThemeData();
     elevatedButtonTheme ??= const ElevatedButtonThemeData();
     outlinedButtonTheme ??= const OutlinedButtonThemeData();
+    textSelectionTheme ??= const TextSelectionThemeData();
+
     fixTextFieldOutlineLabel ??= false;
+    useTextSelectionTheme ??= false;
 
     return ThemeData.raw(
       visualDensity: visualDensity,
@@ -469,7 +474,9 @@ class ThemeData with Diagnosticable {
       textButtonTheme: textButtonTheme,
       elevatedButtonTheme: elevatedButtonTheme,
       outlinedButtonTheme: outlinedButtonTheme,
+      textSelectionTheme: textSelectionTheme,
       fixTextFieldOutlineLabel: fixTextFieldOutlineLabel,
+      useTextSelectionTheme: useTextSelectionTheme,
     );
   }
 
@@ -553,7 +560,9 @@ class ThemeData with Diagnosticable {
     @required this.textButtonTheme,
     @required this.elevatedButtonTheme,
     @required this.outlinedButtonTheme,
+    @required this.textSelectionTheme,
     @required this.fixTextFieldOutlineLabel,
+    @required this.useTextSelectionTheme,
   }) : assert(visualDensity != null),
        assert(primaryColor != null),
        assert(primaryColorBrightness != null),
@@ -620,7 +629,10 @@ class ThemeData with Diagnosticable {
        assert(textButtonTheme != null),
        assert(elevatedButtonTheme != null),
        assert(outlinedButtonTheme != null),
-       assert(fixTextFieldOutlineLabel != null);
+       assert(fixTextFieldOutlineLabel != null),
+       assert(textSelectionTheme != null),
+       assert(fixTextFieldOutlineLabel != null),
+       assert(useTextSelectionTheme != null);
 
   /// Create a [ThemeData] based on the colors in the given [colorScheme] and
   /// text styles of the optional [textTheme].
@@ -1092,6 +1104,9 @@ class ThemeData with Diagnosticable {
   /// [OutlinedButton]s.
   final OutlinedButtonThemeData outlinedButtonTheme;
 
+  /// A theme for customizing the appearance and layout of [TextField] widgets.
+  final TextSelectionThemeData textSelectionTheme;
+
   /// A temporary flag to allow apps to opt-in to a
   /// [small fix](https://github.com/flutter/flutter/issues/54028) for the Y
   /// coordinate of the floating label in a [TextField] [OutlineInputBorder].
@@ -1104,6 +1119,18 @@ class ThemeData with Diagnosticable {
   /// stable release (1.19).
   final bool fixTextFieldOutlineLabel;
 
+  /// A temporary flag to allow apps to opt-in to the new [TextSelectionTheme], with
+  /// its new defaults for the [cursorColor] and [textSelectionHandleColor].
+  ///
+  /// Setting this flag to true will cause the [textSelectionTheme] to be used
+  /// instead of the [cursorColor] and [textSelectionHandleColor] by [TextField]
+  /// and [SelectableText] widgets. In addition, the default values of these
+  /// colors have changed to [ColorScheme.primary].
+  ///
+  /// The flag is currently false by default. It will be removed after migration
+  /// to the [TextSelectionTheme] has been completed.
+  final bool useTextSelectionTheme;
+
   /// Creates a copy of this theme but with the given fields replaced with the new values.
   ///
   /// The [brightness] value is applied to the [colorScheme].
@@ -1178,7 +1205,9 @@ class ThemeData with Diagnosticable {
     TextButtonThemeData textButtonTheme,
     ElevatedButtonThemeData elevatedButtonTheme,
     OutlinedButtonThemeData outlinedButtonTheme,
+    TextSelectionThemeData textSelectionTheme,
     bool fixTextFieldOutlineLabel,
+    bool useTextSelectionTheme,
   }) {
     cupertinoOverrideTheme = cupertinoOverrideTheme?.noDefault();
     return ThemeData.raw(
@@ -1251,7 +1280,9 @@ class ThemeData with Diagnosticable {
       textButtonTheme: textButtonTheme ?? this.textButtonTheme,
       elevatedButtonTheme: elevatedButtonTheme ?? this.elevatedButtonTheme,
       outlinedButtonTheme: outlinedButtonTheme ?? this.outlinedButtonTheme,
+      textSelectionTheme: textSelectionTheme ?? this.textSelectionTheme,
       fixTextFieldOutlineLabel: fixTextFieldOutlineLabel ?? this.fixTextFieldOutlineLabel,
+      useTextSelectionTheme: useTextSelectionTheme ?? this.useTextSelectionTheme,
     );
   }
 
@@ -1402,7 +1433,9 @@ class ThemeData with Diagnosticable {
       textButtonTheme: TextButtonThemeData.lerp(a.textButtonTheme, b.textButtonTheme, t),
       elevatedButtonTheme: ElevatedButtonThemeData.lerp(a.elevatedButtonTheme, b.elevatedButtonTheme, t),
       outlinedButtonTheme: OutlinedButtonThemeData.lerp(a.outlinedButtonTheme, b.outlinedButtonTheme, t),
+      textSelectionTheme: TextSelectionThemeData .lerp(a.textSelectionTheme, b.textSelectionTheme, t),
       fixTextFieldOutlineLabel: t < 0.5 ? a.fixTextFieldOutlineLabel : b.fixTextFieldOutlineLabel,
+      useTextSelectionTheme: t < 0.5 ? a.useTextSelectionTheme : b.useTextSelectionTheme,
     );
   }
 
@@ -1481,7 +1514,9 @@ class ThemeData with Diagnosticable {
         && other.textButtonTheme == textButtonTheme
         && other.elevatedButtonTheme == elevatedButtonTheme
         && other.outlinedButtonTheme == outlinedButtonTheme
-        && other.fixTextFieldOutlineLabel == fixTextFieldOutlineLabel;
+        && other.textSelectionTheme == textSelectionTheme
+        && other.fixTextFieldOutlineLabel == fixTextFieldOutlineLabel
+        && other.useTextSelectionTheme == useTextSelectionTheme;
   }
 
   @override
@@ -1559,7 +1594,9 @@ class ThemeData with Diagnosticable {
       textButtonTheme,
       elevatedButtonTheme,
       outlinedButtonTheme,
+      textSelectionTheme,
       fixTextFieldOutlineLabel,
+      useTextSelectionTheme,
     ];
     return hashList(values);
   }
@@ -1630,6 +1667,8 @@ class ThemeData with Diagnosticable {
     properties.add(DiagnosticsProperty<DividerThemeData>('dividerTheme', dividerTheme, defaultValue: defaultData.dividerTheme, level: DiagnosticLevel.debug));
     properties.add(DiagnosticsProperty<ButtonBarThemeData>('buttonBarTheme', buttonBarTheme, defaultValue: defaultData.buttonBarTheme, level: DiagnosticLevel.debug));
     properties.add(DiagnosticsProperty<TimePickerThemeData>('timePickerTheme', timePickerTheme, defaultValue: defaultData.timePickerTheme, level: DiagnosticLevel.debug));
+    properties.add(DiagnosticsProperty<TextSelectionThemeData>('textSelectionTheme', textSelectionTheme, defaultValue: defaultData.textSelectionTheme, level: DiagnosticLevel.debug));
+    properties.add(DiagnosticsProperty<TextSelectionThemeData>('textSelectionTheme', textSelectionTheme, defaultValue: defaultData.textSelectionTheme, level: DiagnosticLevel.debug));
     properties.add(DiagnosticsProperty<BottomNavigationBarThemeData>('bottomNavigationBarTheme', bottomNavigationBarTheme, defaultValue: defaultData.bottomNavigationBarTheme, level: DiagnosticLevel.debug));
     properties.add(DiagnosticsProperty<TextButtonThemeData>('textButtonTheme', textButtonTheme, defaultValue: defaultData.textButtonTheme, level: DiagnosticLevel.debug));
     properties.add(DiagnosticsProperty<ElevatedButtonThemeData>('elevatedButtonTheme', elevatedButtonTheme, defaultValue: defaultData.elevatedButtonTheme, level: DiagnosticLevel.debug));

packages/flutter/test/material/theme_data_test.dart

@@ -287,7 +287,9 @@ void main() {
       textButtonTheme: TextButtonThemeData(style: TextButton.styleFrom(primary: Colors.red)),
       elevatedButtonTheme: ElevatedButtonThemeData(style: ElevatedButton.styleFrom(primary: Colors.green)),
       outlinedButtonTheme: OutlinedButtonThemeData(style: OutlinedButton.styleFrom(primary: Colors.blue)),
+      textSelectionTheme: const TextSelectionThemeData(cursorColor: Colors.black),
       fixTextFieldOutlineLabel: false,
+      useTextSelectionTheme: false,
     );
 
     final SliderThemeData otherSliderTheme = SliderThemeData.fromPrimaryColors(
@@ -373,7 +375,9 @@ void main() {
       textButtonTheme: const TextButtonThemeData(),
       elevatedButtonTheme: const ElevatedButtonThemeData(),
       outlinedButtonTheme: const OutlinedButtonThemeData(),
+      textSelectionTheme: const TextSelectionThemeData(cursorColor: Colors.white),
       fixTextFieldOutlineLabel: true,
+      useTextSelectionTheme: true,
     );
 
     final ThemeData themeDataCopy = theme.copyWith(
@@ -445,7 +449,9 @@ void main() {
       textButtonTheme: otherTheme.textButtonTheme,
       elevatedButtonTheme: otherTheme.elevatedButtonTheme,
       outlinedButtonTheme: otherTheme.outlinedButtonTheme,
+      textSelectionTheme: otherTheme.textSelectionTheme,
       fixTextFieldOutlineLabel: otherTheme.fixTextFieldOutlineLabel,
+      useTextSelectionTheme: otherTheme.useTextSelectionTheme,
     );
 
     expect(themeDataCopy.brightness, equals(otherTheme.brightness));
@@ -516,7 +522,9 @@ void main() {
     expect(themeDataCopy.textButtonTheme, equals(otherTheme.textButtonTheme));
     expect(themeDataCopy.elevatedButtonTheme, equals(otherTheme.elevatedButtonTheme));
     expect(themeDataCopy.outlinedButtonTheme, equals(otherTheme.outlinedButtonTheme));
+    expect(themeDataCopy.textSelectionTheme, equals(otherTheme.textSelectionTheme));
     expect(themeDataCopy.fixTextFieldOutlineLabel, equals(otherTheme.fixTextFieldOutlineLabel));
+    expect(themeDataCopy.useTextSelectionTheme, equals(otherTheme.useTextSelectionTheme));
   });
 
   testWidgets('ThemeData.toString has less than 200 characters output', (WidgetTester tester) async {