Add WidgetStateMouseCursor example and tests for it. (#155552)

Fixes https://github.com/flutter/flutter/issues/155551

### Description
- Adds example for `WidgetStateMouseCursor`
- Adds tests for `examples/api/lib/widgets/widget_state/widget_state_mouse_cursor.0.dart`

examples/api/lib/widgets/widget_state/widget_state_mouse_cursor.0.dart

@@ -0,0 +1,85 @@
+// 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.
+
+import 'package:flutter/material.dart';
+
+/// Flutter code sample for [WidgetStateMouseCursor].
+
+void main() {
+  runApp(const WidgetStateMouseCursorExampleApp());
+}
+
+class WidgetStateMouseCursorExampleApp extends StatelessWidget {
+  const WidgetStateMouseCursorExampleApp({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      home: Scaffold(
+        appBar: AppBar(title: const Text('WidgetStateMouseCursor Sample')),
+        body: const WidgetStateMouseCursorExample(),
+      ),
+    );
+  }
+}
+
+class ListTileCursor extends WidgetStateMouseCursor {
+  const ListTileCursor();
+
+  @override
+  MouseCursor resolve(Set<WidgetState> states) {
+    if (states.contains(WidgetState.disabled)) {
+      return SystemMouseCursors.forbidden;
+    }
+
+    return SystemMouseCursors.click;
+  }
+
+  @override
+  String get debugDescription => 'ListTileCursor()';
+}
+
+class WidgetStateMouseCursorExample extends StatefulWidget {
+  const WidgetStateMouseCursorExample({super.key});
+
+  @override
+  State<WidgetStateMouseCursorExample> createState() => _WidgetStateMouseCursorExampleState();
+}
+
+class _WidgetStateMouseCursorExampleState extends State<WidgetStateMouseCursorExample> {
+  bool _enabled = false;
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      mainAxisAlignment: MainAxisAlignment.center,
+      children: <Widget>[
+        ListTile(
+          title: const Text('ListTile'),
+          enabled: _enabled,
+          onTap: () {},
+          mouseCursor: const ListTileCursor(),
+        ),
+        const SizedBox(height: 10),
+        Row(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: <Widget>[
+            Text(
+              'Enabled: ',
+              style: Theme.of(context).textTheme.titleSmall,
+            ),
+            Switch(
+              value: _enabled,
+              onChanged: (_) {
+                setState(() {
+                  _enabled = !_enabled;
+                });
+              },
+            ),
+          ],
+        ),
+      ],
+    );
+  }
+}

examples/api/test/widgets/widget_state/widget_state_mouse_cursor.0_test.dart

@@ -0,0 +1,71 @@
+// 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.
+
+import 'dart:ui';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
+import 'package:flutter_api_samples/widgets/widget_state/widget_state_mouse_cursor.0.dart'
+    as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('ListTile displays correct mouse cursor when disabled', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const example.WidgetStateMouseCursorExampleApp(),
+    );
+
+    final TestGesture gesture = await tester.createGesture(
+      kind: PointerDeviceKind.mouse,
+    );
+    await gesture.addPointer(
+      location: tester.getCenter(find.byType(ListTile)),
+    );
+    addTearDown(gesture.removePointer);
+
+    expect(
+      RendererBinding.instance.mouseTracker.debugDeviceActiveCursor(1),
+      SystemMouseCursors.forbidden,
+    );
+  });
+
+  testWidgets('Switch enables ListTile', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const example.WidgetStateMouseCursorExampleApp(),
+    );
+
+    ListTile listTile = tester.widget(find.byType(ListTile));
+    expect(listTile.enabled, isFalse);
+
+    // Enable ListTile using Switch.
+    await tester.tap(find.byType(Switch));
+    await tester.pumpAndSettle();
+
+    listTile = tester.widget(find.byType(ListTile));
+    expect(listTile.enabled, isTrue);
+  });
+
+  testWidgets('ListTile displays correct mouse cursor when enabled', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const example.WidgetStateMouseCursorExampleApp(),
+    );
+
+    // Enable ListTile using Switch.
+    await tester.tap(find.byType(Switch));
+    await tester.pumpAndSettle();
+
+    final TestGesture gesture = await tester.createGesture(
+      kind: PointerDeviceKind.mouse,
+    );
+    await gesture.addPointer(
+      location: tester.getCenter(find.byType(ListTile)),
+    );
+    addTearDown(gesture.removePointer);
+
+    expect(
+      RendererBinding.instance.mouseTracker.debugDeviceActiveCursor(1),
+      SystemMouseCursors.click,
+    );
+  });
+}

packages/flutter/lib/src/widgets/widget_state.dart

@@ -390,7 +390,7 @@ class _WidgetStateColorMapper extends _WidgetStateColorTransparent {
 /// This example defines a mouse cursor that resolves to
 /// [SystemMouseCursors.forbidden] when its widget is disabled.
 ///
-/// ** See code in examples/api/lib/material/material_state/material_state_mouse_cursor.0.dart **
+/// ** See code in examples/api/lib/widgets/widget_state/widget_state_mouse_cursor.0.dart **
 /// {@end-tool}
 ///
 /// This class should only be used for parameters which are documented to take