Mouse onEnter and onExit now support hovering stylus

packages/flutter/lib/src/rendering/mouse_tracker.dart

@@ -300,7 +300,7 @@ class MouseTracker extends ChangeNotifier {
   /// The [updateWithEvent] is one of the two ways of updating mouse
   /// states, the other one being [updateAllDevices].
   void updateWithEvent(PointerEvent event, HitTestResult? hitTestResult) {
-    if (event.kind != PointerDeviceKind.mouse) {
+    if (event.kind != PointerDeviceKind.mouse && event.kind != PointerDeviceKind.stylus) {
       return;
     }
     if (event is PointerSignalEvent) {

packages/flutter/test/material/text_button_test.dart

@@ -2300,6 +2300,52 @@ void main() {
     // The icon is aligned to the left of the button.
     expect(buttonTopLeft.dx, iconTopLeft.dx - 16.0); // 16.0 - padding between icon and button edge.
   });
+
+  testWidgets('treats a hovering stylus like a mouse', (WidgetTester tester) async {
+    final FocusNode focusNode = FocusNode();
+    final ThemeData theme = ThemeData(useMaterial3: true);
+    bool hasBeenHovered = false;
+
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: theme,
+        home: Scaffold(
+          body: Center(
+            child: Builder(
+              builder: (BuildContext context) {
+                return TextButton(
+                  onPressed: () {},
+                  onHover: (bool entered) {
+                    hasBeenHovered = true;
+                  },
+                  focusNode: focusNode,
+                  child: const Text('TextButton'),
+                );
+              },
+            ),
+          ),
+        ),
+      ),
+    );
+
+    RenderObject overlayColor() {
+      return tester.allRenderObjects.firstWhere((RenderObject object) => object.runtimeType.toString() == '_RenderInkFeatures');
+    }
+
+    final Offset center = tester.getCenter(find.byType(TextButton));
+    final TestGesture gesture = await tester.createGesture(
+      kind: PointerDeviceKind.stylus,
+    );
+    await gesture.addPointer();
+    await tester.pumpAndSettle();
+
+    expect(hasBeenHovered, isFalse);
+
+    await gesture.moveTo(center);
+    await tester.pumpAndSettle();
+    expect(overlayColor(), paints..rect(color: theme.colorScheme.primary.withOpacity(0.08)));
+    expect(hasBeenHovered, isTrue);
+  });
 }
 
 TextStyle? _iconStyle(WidgetTester tester, IconData icon) {

packages/flutter/test/rendering/mouse_tracker_test.dart

@@ -72,63 +72,81 @@ void main() {
 
   final Matrix4 translate10by20 = Matrix4.translationValues(10, 20, 0);
 
-  test('should detect enter, hover, and exit from Added, Hover, and Removed events', () {
-    final List<PointerEvent> events = <PointerEvent>[];
-    setUpWithOneAnnotation(logEvents: events);
+  for (final ui.PointerDeviceKind pointerDeviceKind in <ui.PointerDeviceKind>[ui.PointerDeviceKind.mouse, ui.PointerDeviceKind.stylus]) {
+    test('should detect enter, hover, and exit from Added, Hover, and Removed events for stylus', () {
+      final List<PointerEvent> events = <PointerEvent>[];
+      setUpWithOneAnnotation(logEvents: events);
+
+      final List<bool> listenerLogs = <bool>[];
+      _mouseTracker.addListener(() {
+        listenerLogs.add(_mouseTracker.mouseIsConnected);
+      });
 
-    final List<bool> listenerLogs = <bool>[];
-    _mouseTracker.addListener(() {
-      listenerLogs.add(_mouseTracker.mouseIsConnected);
+      expect(_mouseTracker.mouseIsConnected, isFalse);
+
+      // Pointer enters the annotation.
+      RendererBinding.instance.platformDispatcher.onPointerDataPacket!(ui.PointerDataPacket(data: <ui.PointerData>[
+        _pointerData(
+          PointerChange.add,
+          Offset.zero,
+          kind: pointerDeviceKind,
+        ),
+      ]));
+      addTearDown(() => dispatchRemoveDevice());
+
+      expect(events, _equalToEventsOnCriticalFields(<BaseEventMatcher>[
+        EventMatcher<PointerEnterEvent>(const PointerEnterEvent()),
+      ]));
+      expect(listenerLogs, <bool>[true]);
+      events.clear();
+      listenerLogs.clear();
+
+      // Pointer hovers the annotation.
+      RendererBinding.instance.platformDispatcher.onPointerDataPacket!(ui.PointerDataPacket(data: <ui.PointerData>[
+        _pointerData(
+          PointerChange.hover,
+          const Offset(1.0, 101.0),
+          kind: pointerDeviceKind,
+        ),
+      ]));
+      expect(events, _equalToEventsOnCriticalFields(<BaseEventMatcher>[
+        EventMatcher<PointerHoverEvent>(const PointerHoverEvent(position: Offset(1.0, 101.0))),
+      ]));
+      expect(_mouseTracker.mouseIsConnected, isTrue);
+      expect(listenerLogs, isEmpty);
+      events.clear();
+
+      // Pointer is removed while on the annotation.
+      RendererBinding.instance.platformDispatcher.onPointerDataPacket!(ui.PointerDataPacket(data: <ui.PointerData>[
+        _pointerData(
+          PointerChange.remove,
+          const Offset(1.0, 101.0),
+          kind: pointerDeviceKind,
+        ),
+      ]));
+      expect(events, _equalToEventsOnCriticalFields(<BaseEventMatcher>[
+        EventMatcher<PointerExitEvent>(const PointerExitEvent(position: Offset(1.0, 101.0))),
+      ]));
+      expect(listenerLogs, <bool>[false]);
+      events.clear();
+      listenerLogs.clear();
+
+      // Pointer is added on the annotation.
+      RendererBinding.instance.platformDispatcher.onPointerDataPacket!(ui.PointerDataPacket(data: <ui.PointerData>[
+        _pointerData(
+          PointerChange.add,
+          const Offset(0.0, 301.0),
+          kind: pointerDeviceKind,
+        ),
+      ]));
+      expect(events, _equalToEventsOnCriticalFields(<BaseEventMatcher>[
+        EventMatcher<PointerEnterEvent>(const PointerEnterEvent(position: Offset(0.0, 301.0))),
+      ]));
+      expect(listenerLogs, <bool>[true]);
+      events.clear();
+      listenerLogs.clear();
     });
-
-    expect(_mouseTracker.mouseIsConnected, isFalse);
-
-    // Pointer enters the annotation.
-    RendererBinding.instance.platformDispatcher.onPointerDataPacket!(ui.PointerDataPacket(data: <ui.PointerData>[
-      _pointerData(PointerChange.add, Offset.zero),
-    ]));
-    addTearDown(() => dispatchRemoveDevice());
-
-    expect(events, _equalToEventsOnCriticalFields(<BaseEventMatcher>[
-      EventMatcher<PointerEnterEvent>(const PointerEnterEvent()),
-    ]));
-    expect(listenerLogs, <bool>[true]);
-    events.clear();
-    listenerLogs.clear();
-
-    // Pointer hovers the annotation.
-    RendererBinding.instance.platformDispatcher.onPointerDataPacket!(ui.PointerDataPacket(data: <ui.PointerData>[
-      _pointerData(PointerChange.hover, const Offset(1.0, 101.0)),
-    ]));
-    expect(events, _equalToEventsOnCriticalFields(<BaseEventMatcher>[
-      EventMatcher<PointerHoverEvent>(const PointerHoverEvent(position: Offset(1.0, 101.0))),
-    ]));
-    expect(_mouseTracker.mouseIsConnected, isTrue);
-    expect(listenerLogs, isEmpty);
-    events.clear();
-
-    // Pointer is removed while on the annotation.
-    RendererBinding.instance.platformDispatcher.onPointerDataPacket!(ui.PointerDataPacket(data: <ui.PointerData>[
-      _pointerData(PointerChange.remove, const Offset(1.0, 101.0)),
-    ]));
-    expect(events, _equalToEventsOnCriticalFields(<BaseEventMatcher>[
-      EventMatcher<PointerExitEvent>(const PointerExitEvent(position: Offset(1.0, 101.0))),
-    ]));
-    expect(listenerLogs, <bool>[false]);
-    events.clear();
-    listenerLogs.clear();
-
-    // Pointer is added on the annotation.
-    RendererBinding.instance.platformDispatcher.onPointerDataPacket!(ui.PointerDataPacket(data: <ui.PointerData>[
-      _pointerData(PointerChange.add, const Offset(0.0, 301.0)),
-    ]));
-    expect(events, _equalToEventsOnCriticalFields(<BaseEventMatcher>[
-      EventMatcher<PointerEnterEvent>(const PointerEnterEvent(position: Offset(0.0, 301.0))),
-    ]));
-    expect(listenerLogs, <bool>[true]);
-    events.clear();
-    listenerLogs.clear();
-  });
+  }
 
   // Regression test for https://github.com/flutter/flutter/issues/90838
   test('should not crash if the first event is a Removed event', () {
@@ -623,7 +641,10 @@ class BaseEventMatcher extends Matcher {
   bool matches(dynamic untypedItem, Map<dynamic, dynamic> matchState) {
     final PointerEvent actual = untypedItem as PointerEvent;
     if (!(
-      _matchesField(matchState, 'kind', actual.kind, PointerDeviceKind.mouse) &&
+      (
+        _matchesField(matchState, 'kind', actual.kind, PointerDeviceKind.mouse) ||
+        _matchesField(matchState, 'kind', actual.kind, PointerDeviceKind.stylus)
+      ) &&
       _matchesField(matchState, 'position', actual.position, expected.position) &&
       _matchesField(matchState, 'device', actual.device, expected.device) &&
       _matchesField(matchState, 'localPosition', actual.localPosition, expected.localPosition)

packages/flutter/test/widgets/mouse_region_test.dart

@@ -1868,6 +1868,47 @@ void main() {
     await gesture.cancel();
     expect(tester.takeException(), isNull);
   });
+
+  testWidgets('stylus input works', (WidgetTester tester) async {
+    bool onEnter = false;
+    bool onExit = false;
+    bool onHover = false;
+    await tester.pumpWidget(MaterialApp(
+      home: Scaffold(
+        body: MouseRegion(
+          onEnter: (_) => onEnter = true,
+          onExit: (_) => onExit = true,
+          onHover: (_) => onHover = true,
+          child: const SizedBox(
+            width: 10.0,
+            height: 10.0,
+          ),
+        ),
+      ),
+    ));
+
+    final TestGesture gesture = await tester.createGesture(kind: PointerDeviceKind.stylus);
+    await gesture.addPointer(location: const Offset(20.0, 20.0));
+    await tester.pump();
+
+    expect(onEnter, false);
+    expect(onHover, false);
+    expect(onExit, false);
+
+    await gesture.moveTo(const Offset(5.0, 5.0));
+    await tester.pump();
+
+    expect(onEnter, true);
+    expect(onHover, true);
+    expect(onExit, false);
+
+    await gesture.moveTo(const Offset(20.0, 20.0));
+    await tester.pump();
+
+    expect(onEnter, true);
+    expect(onHover, true);
+    expect(onExit, true);
+  });
 }
 
 // Render widget `topLeft` at the top-left corner, stacking on top of the widget