Add mouse cursor property to CupertinoRadio (#149681)

Adds `mouseCursor` property in `Radio` to `CupertinoRadio` and `Radio.adaptive`.

The `mouseCursor` property added is of type `MouseCursor` and not `WidgetStateProperty<MouseCursor>` to match `Radio`'s `mouseCursor`.

Author: victorsanni

packages/flutter/lib/src/cupertino/radio.dart

@@ -71,6 +71,7 @@ class CupertinoRadio<T> extends StatefulWidget {
     required this.value,
     required this.groupValue,
     required this.onChanged,
+    this.mouseCursor,
     this.toggleable = false,
     this.activeColor,
     this.inactiveColor,
@@ -121,6 +122,28 @@ class CupertinoRadio<T> extends StatefulWidget {
   /// ```
   final ValueChanged<T?>? onChanged;
 
+  /// The cursor for a mouse pointer when it enters or is hovering over the
+  /// widget.
+  ///
+  /// If [mouseCursor] is a [WidgetStateMouseCursor],
+  /// [WidgetStateMouseCursor.resolve] is used for the following [WidgetState]s:
+  ///
+  ///  * [WidgetState.selected].
+  ///  * [WidgetState.hovered].
+  ///  * [WidgetState.focused].
+  ///  * [WidgetState.disabled].
+  ///
+  /// If null, then [SystemMouseCursors.basic] is used when this radio button is disabled.
+  /// When this radio button is enabled, [SystemMouseCursors.click] is used on Web, and
+  /// [SystemMouseCursors.basic] is used on other platforms.
+  ///
+  /// See also:
+  ///
+  ///  * [WidgetStateMouseCursor], a [MouseCursor] that implements
+  ///    `WidgetStateProperty` which is used in APIs that need to accept
+  ///    either a [MouseCursor] or a [WidgetStateProperty<MouseCursor>].
+  final MouseCursor? mouseCursor;
+
   /// Set to true if this radio button is allowed to be returned to an
   /// indeterminate state by selecting it again when selected.
   ///
@@ -239,6 +262,15 @@ class _CupertinoRadioState<T> extends State<CupertinoRadio<T>> with TickerProvid
 
     final Color effectiveFillColor = widget.fillColor ?? CupertinoColors.white;
 
+    final WidgetStateProperty<MouseCursor> effectiveMouseCursor =
+      WidgetStateProperty.resolveWith<MouseCursor>((Set<WidgetState> states) {
+        return WidgetStateProperty.resolveAs<MouseCursor?>(widget.mouseCursor, states)
+          ?? (states.contains(WidgetState.disabled)
+              ? SystemMouseCursors.basic
+              : kIsWeb ? SystemMouseCursors.click : SystemMouseCursors.basic
+            );
+      });
+
     final bool? accessibilitySelected;
     // Apple devices also use `selected` to annotate radio button's semantics
     // state.
@@ -258,6 +290,7 @@ class _CupertinoRadioState<T> extends State<CupertinoRadio<T>> with TickerProvid
       checked: widget._selected,
       selected: accessibilitySelected,
       child: buildToggleable(
+        mouseCursor: effectiveMouseCursor,
         focusNode: widget.focusNode,
         autofocus: widget.autofocus,
         onFocusChange: onFocusChange,
@@ -309,7 +342,6 @@ class _RadioPainter extends ToggleablePainter {
 
   @override
   void paint(Canvas canvas, Size size) {
-
     final Offset center = (Offset.zero & size).center;
 
     final Paint paint = Paint()

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

@@ -447,6 +447,7 @@ class _RadioState<T> extends State<Radio<T>> with TickerProviderStateMixin, Togg
               value: widget.value,
               groupValue: widget.groupValue,
               onChanged: widget.onChanged,
+              mouseCursor: widget.mouseCursor,
               toggleable: widget.toggleable,
               activeColor: widget.activeColor,
               focusColor: widget.focusColor,

packages/flutter/test/cupertino/radio_test.dart

@@ -4,6 +4,7 @@
 
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
+import 'package:flutter/gestures.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -428,4 +429,129 @@ void main() {
     // Release pointer after widget disappeared.
     await gesture.up();
   });
+
+  testWidgets('Radio configures mouse cursor', (WidgetTester tester) async {
+    await tester.pumpWidget(CupertinoApp(
+      home: Center(
+        child: CupertinoRadio<int>(
+          value: 1,
+          groupValue: 1,
+          onChanged: (int? i) { },
+          mouseCursor: SystemMouseCursors.forbidden,
+        ),
+      ),
+    ));
+    final TestGesture gesture = await tester.createGesture(
+      kind: PointerDeviceKind.mouse,
+      pointer: 1
+    );
+    addTearDown(gesture.removePointer);
+    await gesture.addPointer(location: tester.getCenter(find.byType(CupertinoRadio<int>)));
+    await tester.pump();
+    await gesture.moveTo(tester.getCenter(find.byType(CupertinoRadio<int>)));
+    expect(
+      RendererBinding.instance.mouseTracker.debugDeviceActiveCursor(1),
+      SystemMouseCursors.forbidden
+    );
+  });
+
+  testWidgets('Mouse cursor resolves in disabled/hovered/focused states', (WidgetTester tester) async {
+    final FocusNode focusNode = FocusNode(debugLabel: 'Radio');
+    tester.binding.focusManager.highlightStrategy = FocusHighlightStrategy.alwaysTraditional;
+
+    await tester.pumpWidget(CupertinoApp(
+      home: Center(
+        child: CupertinoRadio<int>(
+          value: 1,
+          groupValue: 1,
+          onChanged: (int? i) { },
+          mouseCursor: const RadioMouseCursor(),
+          focusNode: focusNode
+        ),
+      ),
+    ));
+    final TestGesture gesture = await tester.createGesture(
+      kind: PointerDeviceKind.mouse,
+      pointer: 1
+    );
+    addTearDown(gesture.removePointer);
+    await gesture.addPointer(location: tester.getCenter(find.byType(CupertinoRadio<int>)));
+    await tester.pump();
+
+    // Test hovered case.
+    await gesture.moveTo(tester.getCenter(find.byType(CupertinoRadio<int>)));
+    expect(
+      RendererBinding.instance.mouseTracker.debugDeviceActiveCursor(1),
+      SystemMouseCursors.click
+    );
+
+    // Test focused case.
+    focusNode.requestFocus();
+    await tester.pump();
+    expect(
+      RendererBinding.instance.mouseTracker.debugDeviceActiveCursor(1),
+      SystemMouseCursors.basic
+    );
+
+    // Test disabled case.
+    await tester.pumpWidget(const CupertinoApp(
+      home: Center(
+        child: CupertinoRadio<int>(
+          value: 1,
+          groupValue: 1,
+          onChanged: null,
+          mouseCursor: RadioMouseCursor(),
+        ),
+      ),
+    ));
+
+    await tester.pump();
+    expect(
+      RendererBinding.instance.mouseTracker.debugDeviceActiveCursor(1),
+      SystemMouseCursors.forbidden
+    );
+    focusNode.dispose();
+  });
+
+  testWidgets('Radio default mouse cursor', (WidgetTester tester) async {
+    await tester.pumpWidget(CupertinoApp(
+      home: Center(
+        child: CupertinoRadio<int>(
+          value: 1,
+          groupValue: 1,
+          onChanged: (int? i) { },
+        ),
+      ),
+    ));
+    final TestGesture gesture = await tester.createGesture(
+      kind: PointerDeviceKind.mouse,
+      pointer: 1
+    );
+    addTearDown(gesture.removePointer);
+    await gesture.addPointer(location: tester.getCenter(find.byType(CupertinoRadio<int>)));
+    await tester.pump();
+    await gesture.moveTo(tester.getCenter(find.byType(CupertinoRadio<int>)));
+    expect(
+      RendererBinding.instance.mouseTracker.debugDeviceActiveCursor(1),
+      kIsWeb ? SystemMouseCursors.click : SystemMouseCursors.basic
+    );
+  });
+}
+
+class RadioMouseCursor extends WidgetStateMouseCursor {
+  const RadioMouseCursor();
+
+  @override
+  MouseCursor resolve(Set<WidgetState> states) {
+    if (states.contains(WidgetState.disabled)) {
+      return SystemMouseCursors.forbidden;
+    }
+    if (states.contains(WidgetState.focused)){
+      return SystemMouseCursors.basic;
+    }
+    return SystemMouseCursors.click;
+  }
+
+  @override
+  String get debugDescription => 'RadioMouseCursor()';
 }