Re-land: Add support for Tooltip hover (#31699)

This is a re-land of #31561, after fixing performance regressions.

Added change listening to the MouseTracker so that the Listener and tooltip can react to whether or not a mouse is connected at all. Added a change check to make sure Listener only repaints when something changed.

Fixes #22817

dev/benchmarks/microbenchmarks/lib/geometry/rrect_contains_bench.dart

@@ -9,6 +9,7 @@ import '../common.dart';
 const int _kNumIters = 10000;
 
 void main() {
+  assert(false, "Don't run benchmarks in checked mode! Use 'flutter run --release'.");
   final Stopwatch watch = Stopwatch();
   print('RRect contains benchmark...');
   watch.start();

dev/benchmarks/microbenchmarks/lib/gestures/velocity_tracker_bench.dart

@@ -10,6 +10,7 @@ import 'data/velocity_tracker_data.dart';
 const int _kNumIters = 10000;
 
 void main() {
+  assert(false, "Don't run benchmarks in checked mode! Use 'flutter run --release'.");
   final VelocityTracker tracker = VelocityTracker();
   final Stopwatch watch = Stopwatch();
   print('Velocity tracker benchmark...');

dev/benchmarks/microbenchmarks/lib/stocks/animation_bench.dart

@@ -34,7 +34,7 @@ class BenchmarkingBinding extends LiveTestWidgetsFlutterBinding {
 }
 
 Future<void> main() async {
-  assert(false); // don't run this in checked mode! Use --release.
+  assert(false, "Don't run benchmarks in checked mode! Use 'flutter run --release'.");
   stock_data.StockData.actuallyFetchData = false;
 
   final Stopwatch wallClockWatch = Stopwatch();

dev/benchmarks/microbenchmarks/lib/stocks/build_bench.dart

@@ -14,7 +14,7 @@ import '../common.dart';
 const Duration kBenchmarkTime = Duration(seconds: 15);
 
 Future<void> main() async {
-  assert(false); // don't run this in checked mode! Use --release.
+  assert(false, "Don't run benchmarks in checked mode! Use 'flutter run --release'.");
   stock_data.StockData.actuallyFetchData = false;
 
   // We control the framePolicy below to prevent us from scheduling frames in

dev/benchmarks/microbenchmarks/lib/stocks/layout_bench.dart

@@ -15,6 +15,7 @@ import '../common.dart';
 const Duration kBenchmarkTime = Duration(seconds: 15);
 
 Future<void> main() async {
+  assert(false, "Don't run benchmarks in checked mode! Use 'flutter run --release'.");
   stock_data.StockData.actuallyFetchData = false;
 
   // We control the framePolicy below to prevent us from scheduling frames in

packages/flutter/lib/src/gestures/mouse_tracking.dart

@@ -4,7 +4,7 @@
 
 import 'dart:ui';
 
-import 'package:flutter/foundation.dart' show visibleForTesting;
+import 'package:flutter/foundation.dart' show ChangeNotifier, visibleForTesting;
 import 'package:flutter/scheduler.dart';
 
 import 'events.dart';
@@ -84,8 +84,11 @@ typedef MouseDetectorAnnotationFinder = MouseTrackerAnnotation Function(Offset o
 /// and notifies them when a mouse pointer enters, moves, or leaves an annotated
 /// region that they are interested in.
 ///
+/// This class is a [ChangeNotifier] that notifies its listeners if the value of
+/// [mouseIsConnected] changes.
+///
 /// Owned by the [RendererBinding] class.
-class MouseTracker {
+class MouseTracker extends ChangeNotifier {
   /// Creates a mouse tracker to keep track of mouse locations.
   ///
   /// All of the parameters must not be null.
@@ -129,8 +132,13 @@ class MouseTracker {
   }
 
   void _scheduleMousePositionCheck() {
-    SchedulerBinding.instance.addPostFrameCallback((Duration _) => collectMousePositions());
-    SchedulerBinding.instance.scheduleFrame();
+    // If we're not tracking anything, then there is no point in registering a
+    // frame callback or scheduling a frame. By definition there are no active
+    // annotations that need exiting, either.
+    if (_trackedAnnotations.isNotEmpty) {
+      SchedulerBinding.instance.addPostFrameCallback((Duration _) => collectMousePositions());
+      SchedulerBinding.instance.scheduleFrame();
+    }
   }
 
   // Handler for events coming from the PointerRouter.
@@ -139,15 +147,12 @@ class MouseTracker {
       return;
     }
     final int deviceId = event.device;
-    if (_trackedAnnotations.isEmpty) {
-      // If we're not tracking anything, then there is no point in registering a
-      // frame callback or scheduling a frame. By definition there are no active
-      // annotations that need exiting, either.
-      _lastMouseEvent.remove(deviceId);
+    if (event is PointerAddedEvent) {
+      _addMouseEvent(deviceId, event);
       return;
     }
     if (event is PointerRemovedEvent) {
-      _lastMouseEvent.remove(deviceId);
+      _removeMouseEvent(deviceId);
       // If the mouse was removed, then we need to schedule one more check to
       // exit any annotations that were active.
       _scheduleMousePositionCheck();
@@ -155,10 +160,10 @@ class MouseTracker {
       if (event is PointerMoveEvent || event is PointerHoverEvent || event is PointerDownEvent) {
         if (!_lastMouseEvent.containsKey(deviceId) || _lastMouseEvent[deviceId].position != event.position) {
           // Only schedule a frame if we have our first event, or if the
-          // location of the mouse has changed.
+          // location of the mouse has changed, and only if there are tracked annotations.
           _scheduleMousePositionCheck();
         }
-        _lastMouseEvent[deviceId] = event;
+        _addMouseEvent(deviceId, event);
       }
     }
   }
@@ -260,6 +265,22 @@ class MouseTracker {
     }
   }
 
+  void _addMouseEvent(int deviceId, PointerEvent event) {
+    final bool wasConnected = mouseIsConnected;
+    _lastMouseEvent[deviceId] = event;
+    if (mouseIsConnected != wasConnected) {
+      notifyListeners();
+    }
+  }
+
+  void _removeMouseEvent(int deviceId) {
+    final bool wasConnected = mouseIsConnected;
+    _lastMouseEvent.remove(deviceId);
+    if (mouseIsConnected != wasConnected) {
+      notifyListeners();
+    }
+  }
+
   /// The most recent mouse event observed for each mouse device ID observed.
   ///
   /// May be null if no mouse is connected, or hasn't produced an event yet.

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

@@ -2565,12 +2565,13 @@ class RenderPointerListener extends RenderProxyBoxWithHitTestBehavior {
   MouseTrackerAnnotation get hoverAnnotation => _hoverAnnotation;
 
   void _updateAnnotations() {
-    assert(_onPointerEnter != _hoverAnnotation.onEnter || _onPointerHover != _hoverAnnotation.onHover || _onPointerExit != _hoverAnnotation.onExit,
-    "Shouldn't call _updateAnnotations if nothing has changed.");
+    bool changed = false;
     if (_hoverAnnotation != null && attached) {
       RendererBinding.instance.mouseTracker.detachAnnotation(_hoverAnnotation);
+      changed = true;
     }
-    if (_onPointerEnter != null || _onPointerHover != null || _onPointerExit != null) {
+    if (RendererBinding.instance.mouseTracker.mouseIsConnected &&
+        (_onPointerEnter != null || _onPointerHover != null || _onPointerExit != null)) {
       _hoverAnnotation = MouseTrackerAnnotation(
         onEnter: _onPointerEnter,
         onHover: _onPointerHover,
@@ -2578,18 +2579,21 @@ class RenderPointerListener extends RenderProxyBoxWithHitTestBehavior {
       );
       if (attached) {
         RendererBinding.instance.mouseTracker.attachAnnotation(_hoverAnnotation);
+        changed = true;
       }
     } else {
       _hoverAnnotation = null;
     }
-    // Needs to paint in any case, in order to insert/remove the annotation
-    // layer associated with the updated _hoverAnnotation.
-    markNeedsPaint();
+    if (changed) {
+      markNeedsPaint();
+    }
   }
 
   @override
   void attach(PipelineOwner owner) {
     super.attach(owner);
+    // Add a listener to listen for changes in mouseIsConnected.
+    RendererBinding.instance.mouseTracker.addListener(_updateAnnotations);
     if (_hoverAnnotation != null) {
       RendererBinding.instance.mouseTracker.attachAnnotation(_hoverAnnotation);
     }
@@ -2600,6 +2604,7 @@ class RenderPointerListener extends RenderProxyBoxWithHitTestBehavior {
     if (_hoverAnnotation != null) {
       RendererBinding.instance.mouseTracker.detachAnnotation(_hoverAnnotation);
     }
+    RendererBinding.instance.mouseTracker.removeListener(_updateAnnotations);
     super.detach();
   }
 

packages/flutter_test/lib/src/controller.dart

@@ -539,12 +539,13 @@ abstract class WidgetController {
   /// You can use [startGesture] instead if your gesture begins with a down
   /// event.
   Future<TestGesture> createGesture({int pointer, PointerDeviceKind kind = PointerDeviceKind.touch}) async {
-    return TestGesture(
+    final TestGesture gesture = TestGesture(
       hitTester: hitTestOnBinding,
       dispatcher: sendEventToBinding,
       kind: kind,
       pointer: pointer ?? _getNextPointer(),
     );
+    return gesture;
   }
 
   /// Creates a gesture with an initial down gesture at a particular point, and

packages/flutter_test/lib/src/test_pointer.dart

@@ -22,9 +22,31 @@ class TestPointer {
   ///
   /// Multiple [TestPointer]s created with the same pointer identifier will
   /// interfere with each other if they are used in parallel.
-  TestPointer([this.pointer = 1, this.kind = PointerDeviceKind.touch])
-      : assert(kind != null),
-        assert(pointer != null);
+  TestPointer([
+    this.pointer = 1,
+    this.kind = PointerDeviceKind.touch,
+    this._device,
+  ])  : assert(kind != null),
+        assert(pointer != null) {
+    switch (kind) {
+      case PointerDeviceKind.mouse:
+        _device ??= 1;
+        break;
+      case PointerDeviceKind.stylus:
+      case PointerDeviceKind.invertedStylus:
+      case PointerDeviceKind.touch:
+      case PointerDeviceKind.unknown:
+        _device ??= 0;
+        break;
+    }
+  }
+
+  /// The device identifier used for events generated by this object.
+  ///
+  /// Set when the object is constructed. Defaults to 1 if the [kind] is
+  /// [PointerDeviceKind.mouse], and 0 otherwise.
+  int get device => _device;
+  int _device;
 
   /// The pointer identifier used for events generated by this object.
   ///
@@ -63,7 +85,8 @@ class TestPointer {
         assert(isDown);
         _isDown = false;
         break;
-      default: break;
+      default:
+        break;
     }
     return isDown;
   }
@@ -72,7 +95,7 @@ class TestPointer {
   ///
   /// By default, the time stamp on the event is [Duration.zero]. You can give a
   /// specific time stamp by passing the `timeStamp` argument.
-  PointerDownEvent down(Offset newLocation, {Duration timeStamp = Duration.zero}) {
+  PointerDownEvent down(Offset newLocation, { Duration timeStamp = Duration.zero }) {
     assert(!isDown);
     _isDown = true;
     _location = newLocation;
@@ -91,7 +114,7 @@ class TestPointer {
   ///
   /// [isDown] must be true when this is called, since move events can only
   /// be generated when the pointer is down.
-  PointerMoveEvent move(Offset newLocation, {Duration timeStamp = Duration.zero}) {
+  PointerMoveEvent move(Offset newLocation, { Duration timeStamp = Duration.zero }) {
     assert(
         isDown,
         'Move events can only be generated when the pointer is down. To '
@@ -114,7 +137,7 @@ class TestPointer {
   /// specific time stamp by passing the `timeStamp` argument.
   ///
   /// The object is no longer usable after this method has been called.
-  PointerUpEvent up({Duration timeStamp = Duration.zero}) {
+  PointerUpEvent up({ Duration timeStamp = Duration.zero }) {
     assert(isDown);
     _isDown = false;
     return PointerUpEvent(
@@ -131,7 +154,7 @@ class TestPointer {
   /// specific time stamp by passing the `timeStamp` argument.
   ///
   /// The object is no longer usable after this method has been called.
-  PointerCancelEvent cancel({Duration timeStamp = Duration.zero}) {
+  PointerCancelEvent cancel({ Duration timeStamp = Duration.zero }) {
     assert(isDown);
     _isDown = false;
     return PointerCancelEvent(
@@ -142,6 +165,43 @@ class TestPointer {
     );
   }
 
+  /// Create a [PointerAddedEvent] with the [PointerDeviceKind] the pointer was
+  /// created with.
+  ///
+  /// By default, the time stamp on the event is [Duration.zero]. You can give a
+  /// specific time stamp by passing the `timeStamp` argument.
+  ///
+  /// [isDown] must be false, since hover events can't be sent when the pointer
+  /// is up.
+  PointerAddedEvent addPointer({
+    Duration timeStamp = Duration.zero,
+  }) {
+    assert(timeStamp != null);
+    return PointerAddedEvent(
+      timeStamp: timeStamp,
+      kind: kind,
+      device: _device,
+    );
+  }
+
+  /// Create a [PointerRemovedEvent] with the kind the pointer was created with.
+  ///
+  /// By default, the time stamp on the event is [Duration.zero]. You can give a
+  /// specific time stamp by passing the `timeStamp` argument.
+  ///
+  /// [isDown] must be false, since hover events can't be sent when the pointer
+  /// is up.
+  PointerRemovedEvent removePointer({
+    Duration timeStamp = Duration.zero,
+  }) {
+    assert(timeStamp != null);
+    return PointerRemovedEvent(
+      timeStamp: timeStamp,
+      kind: kind,
+      device: _device,
+    );
+  }
+
   /// Create a [PointerHoverEvent] to the given location.
   ///
   /// By default, the time stamp on the event is [Duration.zero]. You can give a
@@ -160,12 +220,13 @@ class TestPointer {
         'Hover events can only be generated when the pointer is up. To '
         'simulate movement when the pointer is down, use move() instead.');
     assert(kind != PointerDeviceKind.touch, "Touch pointers can't generate hover events");
-    final Offset delta = location != null ?  newLocation - location : Offset.zero;
+    final Offset delta = location != null ? newLocation - location : Offset.zero;
     _location = newLocation;
     return PointerHoverEvent(
       timeStamp: timeStamp,
       kind: kind,
       position: newLocation,
+      device: _device,
       delta: delta,
     );
   }
@@ -267,12 +328,26 @@ class TestGesture {
     });
   }
 
+  /// In a test, send a pointer add event for this pointer.
+  Future<void> addPointer({ Duration timeStamp = Duration.zero }) {
+    return TestAsyncUtils.guard<void>(() {
+      return _dispatcher(_pointer.addPointer(timeStamp: timeStamp), null);
+    });
+  }
+
+  /// In a test, send a pointer remove event for this pointer.
+  Future<void> removePointer({ Duration timeStamp = Duration.zero }) {
+    return TestAsyncUtils.guard<void>(() {
+      return _dispatcher(_pointer.removePointer(timeStamp: timeStamp), null);
+    });
+  }
+
   /// Send a move event moving the pointer by the given offset.
   ///
   /// If the pointer is down, then a move event is dispatched. If the pointer is
   /// up, then a hover event is dispatched. Touch devices are not able to send
   /// hover events.
-  Future<void> moveBy(Offset offset, {Duration timeStamp = Duration.zero}) {
+  Future<void> moveBy(Offset offset, { Duration timeStamp = Duration.zero }) {
     return moveTo(_pointer.location + offset, timeStamp: timeStamp);
   }
 
@@ -281,7 +356,7 @@ class TestGesture {
   /// If the pointer is down, then a move event is dispatched. If the pointer is
   /// up, then a hover event is dispatched. Touch devices are not able to send
   /// hover events.
-  Future<void> moveTo(Offset location, {Duration timeStamp = Duration.zero}) {
+  Future<void> moveTo(Offset location, { Duration timeStamp = Duration.zero }) {
     return TestAsyncUtils.guard<void>(() {
       if (_pointer._isDown) {
         assert(_result != null,