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Unverified Commit 53636374 authored by Tong Mu's avatar Tong Mu Committed by GitHub
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Rewrite MouseTracker's tracking and notifying algorithm (#42031) 

* Redesigns the algorithm with which MouseTracker keeps track of states and dispatches events.
parent ff2fdf40
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Showing with 783 additions and 345 deletions
packages/flutter/lib/src/foundation/diagnostics.dart
View file @ 53636374
......@@ -2435,7 +2435,7 @@ class ObjectFlagProperty<T> extends DiagnosticsProperty<T> {
///
/// See also:
///
/// * [ObjectFlagSummary], which provides similar functionality but accepts
/// * [ObjectFlagProperty], which provides similar functionality but accepts
/// only one flag, and is preferred if there is only one entry.
/// * [IterableProperty], which provides similar functionality describing
/// the values a collection of objects.
......
packages/flutter/lib/src/gestures/mouse_tracking.dart
View file @ 53636374
......@@ -2,9 +2,10 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'dart:collection' show LinkedHashSet;
import 'dart:ui';
import 'package:flutter/foundation.dart' show ChangeNotifier, visibleForTesting;
import 'package:flutter/foundation.dart';
import 'package:flutter/scheduler.dart';
import 'events.dart';
......@@ -48,49 +49,82 @@ class MouseTrackerAnnotation {
@override
String toString() {
final String none = (onEnter == null && onExit == null && onHover == null) ? ' <none>' : '';
return '[$runtimeType${hashCode.toRadixString(16)}$none'
'${onEnter == null ? '' : ' onEnter'}'
'${onHover == null ? '' : ' onHover'}'
'${onExit == null ? '' : ' onExit'}]';
final List<String> callbacks = <String>[];
if (onEnter != null)
callbacks.add('enter');
if (onHover != null)
callbacks.add('hover');
if (onExit != null)
callbacks.add('exit');
final String describeCallbacks = callbacks.isEmpty
? '<none>'
: callbacks.join(' ');
return '${describeIdentity(this)}(callbacks: $describeCallbacks)';
}
}
// Used internally by the MouseTracker for accounting for which annotation is
// active on which devices inside of the MouseTracker.
class _TrackedAnnotation {
_TrackedAnnotation(this.annotation);
final MouseTrackerAnnotation annotation;
/// Tracks devices that are currently active for this annotation.
///
/// If the mouse pointer corresponding to the integer device ID is
/// present in the Set, then it is currently inside of the annotated layer.
///
/// This is used to detect layers that used to have the mouse pointer inside
/// them, but now no longer do (to facilitate exit notification).
Set<int> activeDevices = <int>{};
}
/// Describes a function that finds an annotation given an offset in logical
/// coordinates.
/// Signature for searching for [MouseTrackerAnnotation]s at the given offset.
///
/// It is used by the [MouseTracker] to fetch annotations for the mouse
/// position.
typedef MouseDetectorAnnotationFinder = Iterable<MouseTrackerAnnotation> Function(Offset offset);
/// Keeps state about which objects are interested in tracking mouse positions
/// and notifies them when a mouse pointer enters, moves, or leaves an annotated
/// region that they are interested in.
// Various states of each connected mouse device.
//
// It is used by [MouseTracker] to compute which callbacks should be triggered
// by each event.
class _MouseState {
_MouseState({
@required PointerEvent mostRecentEvent,
}) : assert(mostRecentEvent != null),
_mostRecentEvent = mostRecentEvent;
// The list of annotations that contains this device during the last frame.
//
// It uses [LinkedHashSet] to keep the insertion order.
LinkedHashSet<MouseTrackerAnnotation> lastAnnotations = LinkedHashSet<MouseTrackerAnnotation>();
// The most recent mouse event observed from this device.
//
// The [mostRecentEvent] is never null.
PointerEvent get mostRecentEvent => _mostRecentEvent;
PointerEvent _mostRecentEvent;
set mostRecentEvent(PointerEvent value) {
assert(value != null);
assert(value.device == _mostRecentEvent.device);
_mostRecentEvent = value;
}
int get device => _mostRecentEvent.device;
@override
String toString() {
final String describeEvent = '${_mostRecentEvent.runtimeType}(device: ${_mostRecentEvent.device})';
final String describeAnnotations = '[list of ${lastAnnotations.length}]';
return '${describeIdentity(this)}(event: $describeEvent, annotations: $describeAnnotations)';
}
}
/// Maintains the relationship between mouse devices and
/// [MouseTrackerAnnotation]s, and notifies interested callbacks of the changes
/// thereof.
///
/// This class is a [ChangeNotifier] that notifies its listeners if the value of
/// [mouseIsConnected] changes.
///
/// Owned by the [RendererBinding] class.
/// An instance of [MouseTracker] is owned by the global singleton of
/// [RendererBinding].
class MouseTracker extends ChangeNotifier {
/// Creates a mouse tracker to keep track of mouse locations.
///
/// The first parameter is a [PointerRouter], which [MouseTracker] will
/// subscribe to and receive events from. Usually it is the global singleton
/// instance [GestureBinding.pointerRouter].
///
/// The second parameter is a function with which the [MouseTracker] can
/// search for [MouseTrackerAnnotation]s at a given position.
/// Usually it is [Layer.findAll] of the root layer.
///
/// All of the parameters must not be null.
MouseTracker(this._router, this.annotationFinder)
: assert(_router != null),
......@@ -104,60 +138,67 @@ class MouseTracker extends ChangeNotifier {
_router.removeGlobalRoute(_handleEvent);
}
// The pointer router that the mouse tracker listens to for events.
final PointerRouter _router;
/// Used to find annotations at a given logical coordinate.
/// Find annotations at a given offset in global logical coordinate space
/// in visual order from front to back.
///
/// [MouseTracker] uses this callback to know which annotations are affected
/// by each device.
///
/// The annotations should be returned in visual order from front to
/// back, so that the callbacks are called in an correct order.
final MouseDetectorAnnotationFinder annotationFinder;
// The collection of annotations that are currently being tracked. They may or
// may not be active, depending on the value of _TrackedAnnotation.active.
final Map<MouseTrackerAnnotation, _TrackedAnnotation> _trackedAnnotations = <MouseTrackerAnnotation, _TrackedAnnotation>{};
// The pointer router that the mouse tracker listens to, and receives new
// mouse events from.
final PointerRouter _router;
/// Track an annotation so that if the mouse enters it, we send it events.
///
/// This is typically called when the [AnnotatedRegion] containing this
/// annotation has been added to the layer tree.
void attachAnnotation(MouseTrackerAnnotation annotation) {
_trackedAnnotations[annotation] = _TrackedAnnotation(annotation);
// Schedule a check so that we test this new annotation to see if any mouse
// is currently inside its region. It has to happen after the frame is
// complete so that the annotation layer has been added before the check.
if (mouseIsConnected) {
_scheduleMousePositionCheck();
// Tracks the state of connected mouse devices.
//
// It is the source of truth for the list of connected mouse devices.
final Map<int, _MouseState> _mouseStates = <int, _MouseState>{};
// Returns the mouse state of a device. If it doesn't exist, create one using
// `mostRecentEvent`.
//
// The returned value is never null.
_MouseState _guaranteeMouseState(int device, PointerEvent mostRecentEvent) {
final _MouseState currentState = _mouseStates[device];
if (currentState == null) {
_addMouseDevice(device, mostRecentEvent);
}
final _MouseState result = currentState ?? _mouseStates[device];
assert(result != null);
return result;
}
/// Stops tracking an annotation, indicating that it has been removed from the
/// layer tree.
///
/// An assertion error will be thrown if the associated layer is not removed
/// and receives another mouse hit.
void detachAnnotation(MouseTrackerAnnotation annotation) {
final _TrackedAnnotation trackedAnnotation = _findAnnotation(annotation);
for (int deviceId in trackedAnnotation.activeDevices) {
if (annotation.onExit != null) {
final PointerEvent event = _lastMouseEvent[deviceId] ?? _pendingRemovals[deviceId];
assert(event != null);
annotation.onExit(PointerExitEvent.fromMouseEvent(event));
}
// The collection of annotations that are currently being tracked.
// It is operated on by [attachAnnotation] and [detachAnnotation].
final Set<MouseTrackerAnnotation> _trackedAnnotations = <MouseTrackerAnnotation>{};
bool get _hasAttachedAnnotations => _trackedAnnotations.isNotEmpty;
void _addMouseDevice(int device, PointerEvent event) {
final bool wasConnected = mouseIsConnected;
assert(!_mouseStates.containsKey(device));
_mouseStates[device] = _MouseState(mostRecentEvent: event);
// Schedule a check to enter annotations that might contain this pointer.
_checkDeviceUpdates(device: device);
if (mouseIsConnected != wasConnected) {
notifyListeners();
}
_trackedAnnotations.remove(annotation);
}
bool _scheduledPostFramePositionCheck = false;
// Schedules a position check at the end of this frame for those annotations
// that have been added.
void _scheduleMousePositionCheck() {
// 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 && !_scheduledPostFramePositionCheck) {
_scheduledPostFramePositionCheck = true;
SchedulerBinding.instance.addPostFrameCallback((Duration duration) {
_sendMouseNotifications(_lastMouseEvent.keys);
_scheduledPostFramePositionCheck = false;
});
void _removeMouseDevice(int device, PointerEvent event) {
final bool wasConnected = mouseIsConnected;
assert(_mouseStates.containsKey(device));
final _MouseState disconnectedMouseState = _mouseStates.remove(device);
disconnectedMouseState.mostRecentEvent = event;
// Schedule a check to exit annotations that used to contain this pointer.
_checkDeviceUpdates(
device: device,
disconnectedMouseState: disconnectedMouseState,
);
if (mouseIsConnected != wasConnected) {
notifyListeners();
}
}
......@@ -166,170 +207,199 @@ class MouseTracker extends ChangeNotifier {
if (event.kind != PointerDeviceKind.mouse) {
return;
}
final int deviceId = event.device;
final int device = event.device;
if (event is PointerAddedEvent) {
// If we are adding the device again, then we're not removing it anymore.
_pendingRemovals.remove(deviceId);
_addMouseEvent(deviceId, event);
_sendMouseNotifications(<int>{deviceId});
return;
}
if (event is PointerRemovedEvent) {
_removeMouseEvent(deviceId, event);
// If the mouse was removed, then we need to schedule one more check to
// exit any annotations that were active.
_sendMouseNotifications(<int>{deviceId});
} else {
if (event is PointerMoveEvent || event is PointerHoverEvent || event is PointerDownEvent) {
final PointerEvent lastEvent = _lastMouseEvent[deviceId];
_addMouseEvent(deviceId, event);
if (lastEvent == null ||
lastEvent is PointerAddedEvent || lastEvent.position != event.position) {
// Only schedule a frame if we have our first event, or if the
// location of the mouse has changed, and only if there are tracked annotations.
_sendMouseNotifications(<int>{deviceId});
}
_addMouseDevice(device, event);
} else if (event is PointerRemovedEvent) {
_removeMouseDevice(device, event);
} else if (event is PointerHoverEvent) {
final _MouseState mouseState = _guaranteeMouseState(device, event);
final PointerEvent previousEvent = mouseState.mostRecentEvent;
mouseState.mostRecentEvent = event;
if (previousEvent is PointerAddedEvent || previousEvent.position != event.position) {
// Only send notifications if we have our first event, or if the
// location of the mouse has changed
_checkDeviceUpdates(device: device);
}
}
}
_TrackedAnnotation _findAnnotation(MouseTrackerAnnotation annotation) {
final _TrackedAnnotation trackedAnnotation = _trackedAnnotations[annotation];
assert(
trackedAnnotation != null,
'Unable to find annotation $annotation in tracked annotations. '
'Check that attachAnnotation has been called for all annotated layers.');
return trackedAnnotation;
bool _scheduledPostFramePositionCheck = false;
// Schedules a position check at the end of this frame.
// It is only called during a frame during which annotations have been added.
void _scheduleMousePositionCheck() {
// 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 (!_scheduledPostFramePositionCheck) {
_scheduledPostFramePositionCheck = true;
SchedulerBinding.instance.addPostFrameCallback((Duration duration) {
_checkAllDevicesUpdates();
_scheduledPostFramePositionCheck = false;
});
}
}
/// Checks if the given [MouseTrackerAnnotation] is attached to this
/// [MouseTracker].
///
/// This function is only public to allow for proper testing of the
/// MouseTracker. Do not call in other contexts.
@visibleForTesting
bool isAnnotationAttached(MouseTrackerAnnotation annotation) {
return _trackedAnnotations.containsKey(annotation);
// Collect the latest states of the given mouse device `device`, and call
// interested callbacks.
//
// The enter or exit events are called for annotations that the pointer
// enters or leaves, while hover events are always called for each
// annotations that the pointer stays in, even if the pointer has not moved
// since the last call. Therefore it's caller's responsibility to check if
// the pointer has moved.
//
// If `disconnectedMouseState` is provided, this state will be used instead,
// but this mouse will be hovering no annotations.
void _checkDeviceUpdates({
int device,
_MouseState disconnectedMouseState,
}) {
final _MouseState mouseState = disconnectedMouseState ?? _mouseStates[device];
final bool thisDeviceIsConnected = mouseState != disconnectedMouseState;
assert(mouseState != null);
final LinkedHashSet<MouseTrackerAnnotation> nextAnnotations =
(_hasAttachedAnnotations && thisDeviceIsConnected)
? LinkedHashSet<MouseTrackerAnnotation>.from(
annotationFinder(mouseState.mostRecentEvent.position)
)
: <MouseTrackerAnnotation>{};
_dispatchDeviceCallbacks(
currentState: mouseState,
nextAnnotations: nextAnnotations,
);
mouseState.lastAnnotations = nextAnnotations;
}
// Tells interested objects that a mouse has entered, exited, or moved, given
// a callback to fetch the [MouseTrackerAnnotation] associated with a global
// offset.
// Collect the latest states of all mouse devices, and call interested
// callbacks.
//
// This is called from a post-frame callback when the layer tree has been
// updated, right after rendering the frame.
void _sendMouseNotifications(Iterable<int> deviceIds) {
if (_trackedAnnotations.isEmpty) {
return;
// For detailed behaviors, see [_checkDeviceUpdates].
void _checkAllDevicesUpdates() {
for (final int device in _mouseStates.keys) {
_checkDeviceUpdates(device: device);
}
}
void exitAnnotation(_TrackedAnnotation trackedAnnotation, int deviceId) {
if (trackedAnnotation.annotation?.onExit != null && trackedAnnotation.activeDevices.contains(deviceId)) {
final PointerEvent event = _lastMouseEvent[deviceId] ?? _pendingRemovals[deviceId];
assert(event != null);
trackedAnnotation.annotation.onExit(PointerExitEvent.fromMouseEvent(event));
// Dispatch callbacks related to a device after all necessary information
// has been collected.
//
// This function should not change the provided states, and should not access
// information that is not provided in parameters (hence being static).
static void _dispatchDeviceCallbacks({
@required LinkedHashSet<MouseTrackerAnnotation> nextAnnotations,
@required _MouseState currentState,
}) {
// Order is important for mouse event callbacks. The `findAnnotations`
// returns annotations in the visual order from front to back. We call
// it the "visual order", and the opposite one "reverse visual order".
// The algorithm here is explained in
// https://github.com/flutter/flutter/issues/41420
// The `nextAnnotations` is annotations that contains this device in the
// coming frame in visual order.
// Order is preserved with the help of [LinkedHashSet].
final PointerEvent mostRecentEvent = currentState.mostRecentEvent;
// The `lastAnnotations` is annotations that contains this device in the
// previous frame in visual order.
final LinkedHashSet<MouseTrackerAnnotation> lastAnnotations = currentState.lastAnnotations;
// Send exit events in visual order.
final Iterable<MouseTrackerAnnotation> exitingAnnotations =
lastAnnotations.difference(nextAnnotations);
for (final MouseTrackerAnnotation annotation in exitingAnnotations) {
if (annotation.onExit != null) {
annotation.onExit(PointerExitEvent.fromMouseEvent(mostRecentEvent));
}
trackedAnnotation.activeDevices.remove(deviceId);
}
void exitAllDevices(_TrackedAnnotation trackedAnnotation) {
if (trackedAnnotation.activeDevices.isNotEmpty) {
final Set<int> deviceIds = trackedAnnotation.activeDevices.toSet();
for (int deviceId in deviceIds) {
exitAnnotation(trackedAnnotation, deviceId);
}
// Send enter events in reverse visual order.
final Iterable<MouseTrackerAnnotation> enteringAnnotations =
nextAnnotations.difference(lastAnnotations).toList().reversed;
for (final MouseTrackerAnnotation annotation in enteringAnnotations) {
if (annotation.onEnter != null) {
annotation.onEnter(PointerEnterEvent.fromMouseEvent(mostRecentEvent));
}
}
try {
// This indicates that all mouse pointers were removed, or none have been
// connected yet. If no mouse is connected, then we want to make sure that
// all active annotations are exited.
if (!mouseIsConnected) {
_trackedAnnotations.values.forEach(exitAllDevices);
return;
}
for (int deviceId in deviceIds) {
final PointerEvent lastEvent = _lastMouseEvent[deviceId];
assert(lastEvent != null);
final Iterable<MouseTrackerAnnotation> hits = annotationFinder(lastEvent.position);
// No annotations were found at this position for this deviceId, so send an
// exit to all active tracked annotations, since none of them were hit.
if (hits.isEmpty) {
// Send an exit to all tracked animations tracking this deviceId.
for (_TrackedAnnotation trackedAnnotation in _trackedAnnotations.values) {
exitAnnotation(trackedAnnotation, deviceId);
}
continue;
}
final Set<_TrackedAnnotation> hitAnnotations = hits.map<_TrackedAnnotation>((MouseTrackerAnnotation hit) => _findAnnotation(hit)).toSet();
for (_TrackedAnnotation hitAnnotation in hitAnnotations) {
if (!hitAnnotation.activeDevices.contains(deviceId)) {
// A tracked annotation that just became active and needs to have an enter
// event sent to it.
hitAnnotation.activeDevices.add(deviceId);
if (hitAnnotation.annotation?.onEnter != null) {
hitAnnotation.annotation.onEnter(PointerEnterEvent.fromMouseEvent(lastEvent));
}
}
if (hitAnnotation.annotation?.onHover != null && lastEvent is PointerHoverEvent) {
hitAnnotation.annotation.onHover(lastEvent);
}
// Tell any tracked annotations that weren't hit that they are no longer
// active.
for (_TrackedAnnotation trackedAnnotation in _trackedAnnotations.values) {
if (hitAnnotations.contains(trackedAnnotation)) {
continue;
}
if (trackedAnnotation.activeDevices.contains(deviceId)) {
if (trackedAnnotation.annotation?.onExit != null) {
trackedAnnotation.annotation.onExit(PointerExitEvent.fromMouseEvent(lastEvent));
}
trackedAnnotation.activeDevices.remove(deviceId);
}
}
// Send hover events in reverse visual order.
// For now the order between the hover events is designed this way for no
// solid reasons but to keep it aligned with enter events for simplicity.
if (mostRecentEvent is PointerHoverEvent) {
final Iterable<MouseTrackerAnnotation> hoveringAnnotations =
nextAnnotations.toList().reversed;
for (final MouseTrackerAnnotation annotation in hoveringAnnotations) {
if (annotation.onHover != null) {
annotation.onHover(mostRecentEvent);
}
}
} finally {
_pendingRemovals.clear();
}
}
void _addMouseEvent(int deviceId, PointerEvent event) {
final bool wasConnected = mouseIsConnected;
if (event is PointerAddedEvent) {
// If we are adding the device again, then we're not removing it anymore.
_pendingRemovals.remove(deviceId);
}
_lastMouseEvent[deviceId] = event;
if (mouseIsConnected != wasConnected) {
notifyListeners();
}
/// Checks if the given [MouseTrackerAnnotation] is attached to this
/// [MouseTracker].
///
/// This function is only public to allow for proper testing of the
/// MouseTracker. Do not call in other contexts.
@visibleForTesting
bool isAnnotationAttached(MouseTrackerAnnotation annotation) {
return _trackedAnnotations.contains(annotation);
}
void _removeMouseEvent(int deviceId, PointerEvent event) {
final bool wasConnected = mouseIsConnected;
assert(event is PointerRemovedEvent);
_pendingRemovals[deviceId] = event;
_lastMouseEvent.remove(deviceId);
if (mouseIsConnected != wasConnected) {
notifyListeners();
/// Whether or not a mouse is connected and has produced events.
bool get mouseIsConnected => _mouseStates.isNotEmpty;
/// Notify [MouseTracker] that a new mouse tracker annotation has started to
/// take effect.
///
/// This should be called as soon as the layer that owns this annotation is
/// added to the layer tree.
///
/// This triggers [MouseTracker] to schedule a mouse position check during the
/// post frame to see if this new annotation might trigger enter events.
///
/// The [MouseTracker] also uses this to track the number of attached
/// annotations, and will skip mouse position checks if there is no
/// annotations attached.
void attachAnnotation(MouseTrackerAnnotation annotation) {
// Schedule a check so that we test this new annotation to see if any mouse
// is currently inside its region. It has to happen after the frame is
// complete so that the annotation layer has been added before the check.
_trackedAnnotations.add(annotation);
if (mouseIsConnected) {
_scheduleMousePositionCheck();
}
}
// A list of device IDs that should be removed and notified when scheduling a
// mouse position check.
final Map<int, PointerRemovedEvent> _pendingRemovals = <int, PointerRemovedEvent>{};
/// The most recent mouse event observed for each mouse device ID observed.
/// Notify [MouseTracker] that a mouse tracker annotation that was previously
/// attached has stopped taking effect.
///
/// May be null if no mouse is connected, or hasn't produced an event yet.
final Map<int, PointerEvent> _lastMouseEvent = <int, PointerEvent>{};
/// Whether or not a mouse is connected and has produced events.
bool get mouseIsConnected => _lastMouseEvent.isNotEmpty;
/// This should be called as soon as the layer that owns this annotation is
/// removed from the layer tree. An assertion error will be thrown if the
/// associated layer is not removed and receives another mouse hit.
///
/// This triggers [MouseTracker] to perform a mouse position check immediately
/// to see if this annotation removal triggers any exit events.
///
/// The [MouseTracker] also uses this to track the number of attached
/// annotations, and will skip mouse position checks if there is no
/// annotations attached.
void detachAnnotation(MouseTrackerAnnotation annotation) {
_mouseStates.forEach((int device, _MouseState mouseState) {
if (mouseState.lastAnnotations.contains(annotation)) {
if (annotation.onExit != null) {
final PointerEvent event = mouseState.mostRecentEvent;
assert(event != null);
annotation.onExit(PointerExitEvent.fromMouseEvent(event));
}
mouseState.lastAnnotations.remove(annotation);
}
});
_trackedAnnotations.remove(annotation);
}
}
packages/flutter/test/gestures/mouse_tracking_test.dart
View file @ 53636374
......@@ -16,211 +16,579 @@ import '../flutter_test_alternative.dart';
typedef HandleEventCallback = void Function(PointerEvent event);
class TestGestureFlutterBinding extends BindingBase with ServicesBinding, SchedulerBinding, GestureBinding, SemanticsBinding, RendererBinding {
HandleEventCallback callback;
class _TestGestureFlutterBinding extends BindingBase
with ServicesBinding, SchedulerBinding, GestureBinding, SemanticsBinding, RendererBinding {
@override
void initInstances() {
super.initInstances();
postFrameCallbacks = <void Function(Duration)>[];
}
List<void Function(Duration)> postFrameCallbacks;
// Proxy post-frame callbacks
@override
void handleEvent(PointerEvent event, HitTestEntry entry) {
super.handleEvent(event, entry);
if (callback != null) {
callback(event);
void addPostFrameCallback(void Function(Duration) callback) {
postFrameCallbacks.add(callback);
}
void flushPostFrameCallbacks(Duration duration) {
for (final void Function(Duration) callback in postFrameCallbacks) {
callback(duration);
}
postFrameCallbacks.clear();
}
}
TestGestureFlutterBinding _binding = TestGestureFlutterBinding();
_TestGestureFlutterBinding _binding = _TestGestureFlutterBinding();
MouseTracker get _mouseTracker => RendererBinding.instance.mouseTracker;
void ensureTestGestureBinding() {
_binding ??= TestGestureFlutterBinding();
void _ensureTestGestureBinding() {
_binding ??= _TestGestureFlutterBinding();
assert(GestureBinding.instance != null);
}
void main() {
setUp(ensureTestGestureBinding);
final List<PointerEvent> events = <PointerEvent>[];
final MouseTrackerAnnotation annotation = MouseTrackerAnnotation(
onEnter: (PointerEnterEvent event) => events.add(event),
onHover: (PointerHoverEvent event) => events.add(event),
onExit: (PointerExitEvent event) => events.add(event),
);
// Only respond to some mouse events.
final MouseTrackerAnnotation partialAnnotation = MouseTrackerAnnotation(
onEnter: (PointerEnterEvent event) => events.add(event),
onHover: (PointerHoverEvent event) => events.add(event),
);
bool isInHitRegionOne;
bool isInHitRegionTwo;
void _setUpMouseAnnotationFinder(MouseDetectorAnnotationFinder annotationFinder) {
final MouseTracker mouseTracker = MouseTracker(
GestureBinding.instance.pointerRouter,
annotationFinder,
);
RendererBinding.instance.initMouseTracker(mouseTracker);
}
void clear() {
events.clear();
// Set up a trivial test environment that includes one annotation, which adds
// the enter, hover, and exit events it received to [logEvents].
MouseTrackerAnnotation _setUpWithOneAnnotation({List<PointerEvent> logEvents}) {
final MouseTrackerAnnotation annotation = MouseTrackerAnnotation(
onEnter: (PointerEnterEvent event) => logEvents.add(event),
onHover: (PointerHoverEvent event) => logEvents.add(event),
onExit: (PointerExitEvent event) => logEvents.add(event),
);
_setUpMouseAnnotationFinder(
(Offset position) sync* {
yield annotation;
},
);
_mouseTracker.attachAnnotation(annotation);
return annotation;
}
setUp(() {
clear();
isInHitRegionOne = true;
isInHitRegionTwo = false;
RendererBinding.instance.initMouseTracker(
MouseTracker(
GestureBinding.instance.pointerRouter,
(Offset position) sync* {
if (isInHitRegionOne)
yield annotation;
else if (isInHitRegionTwo) {
yield partialAnnotation;
}
},
),
);
_ensureTestGestureBinding();
_binding.postFrameCallbacks.clear();
PointerEventConverter.clearPointers();
});
test('receives and processes mouse hover events', () {
final ui.PointerDataPacket packet1 = ui.PointerDataPacket(data: <ui.PointerData>[
// Will implicitly also add a PointerAdded event.
_pointerData(PointerChange.hover, const Offset(0.0, 0.0)),
]);
final ui.PointerDataPacket packet2 = ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(1.0, 101.0)),
]);
final ui.PointerDataPacket packet3 = ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.remove, const Offset(1.0, 201.0)),
]);
final ui.PointerDataPacket packet4 = ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(1.0, 301.0)),
]);
final ui.PointerDataPacket packet5 = ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(1.0, 401.0), device: 1),
]);
RendererBinding.instance.mouseTracker.attachAnnotation(annotation);
isInHitRegionOne = true;
ui.window.onPointerDataPacket(packet1);
test('MouseTrackerAnnotation has correct toString', () {
final MouseTrackerAnnotation annotation1 = MouseTrackerAnnotation(
onEnter: (_) {},
onExit: (_) {},
onHover: (_) {},
);
expect(
annotation1.toString(),
equals('MouseTrackerAnnotation#${shortHash(annotation1)}(callbacks: enter hover exit)'),
);
const MouseTrackerAnnotation annotation2 = MouseTrackerAnnotation();
expect(
annotation2.toString(),
equals('MouseTrackerAnnotation#${shortHash(annotation2)}(callbacks: <none>)'),
);
});
test('should detect enter, hover, and exit from Added, Hover, and Removed events', () {
final List<PointerEvent> events = <PointerEvent>[];
_setUpWithOneAnnotation(logEvents: events);
final List<bool> listenerLogs = <bool>[];
_mouseTracker.addListener(() {
listenerLogs.add(_mouseTracker.mouseIsConnected);
});
expect(_mouseTracker.mouseIsConnected, isFalse);
// Enter
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(1.0, 0.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerEnterEvent(position: Offset(0.0, 0.0)),
const PointerHoverEvent(position: Offset(0.0, 0.0)),
const PointerEnterEvent(position: Offset(1.0, 0.0)),
const PointerHoverEvent(position: Offset(1.0, 0.0)),
]));
clear();
expect(listenerLogs, <bool>[true]);
events.clear();
listenerLogs.clear();
ui.window.onPointerDataPacket(packet2);
// Hover
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(1.0, 101.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerHoverEvent(position: Offset(1.0, 101.0)),
]));
clear();
expect(_mouseTracker.mouseIsConnected, isTrue);
expect(listenerLogs, <bool>[]);
events.clear();
ui.window.onPointerDataPacket(packet3);
// Remove
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.remove, const Offset(1.0, 201.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerHoverEvent(position: Offset(1.0, 201.0)),
const PointerExitEvent(position: Offset(1.0, 201.0)),
]));
expect(listenerLogs, <bool>[false]);
events.clear();
listenerLogs.clear();
clear();
ui.window.onPointerDataPacket(packet4);
// Add again
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(1.0, 301.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerEnterEvent(position: Offset(1.0, 301.0)),
const PointerHoverEvent(position: Offset(1.0, 301.0)),
]));
expect(listenerLogs, <bool>[true]);
events.clear();
listenerLogs.clear();
});
test('should correctly handle multiple devices', () {
final List<PointerEvent> events = <PointerEvent>[];
_setUpWithOneAnnotation(logEvents: events);
expect(_mouseTracker.mouseIsConnected, isFalse);
// First mouse
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 1.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerEnterEvent(position: Offset(0.0, 1.0)),
const PointerHoverEvent(position: Offset(0.0, 1.0)),
]));
expect(_mouseTracker.mouseIsConnected, isTrue);
events.clear();
// add in a second mouse simultaneously.
clear();
ui.window.onPointerDataPacket(packet5);
// Second mouse
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(1.0, 401.0), device: 1),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerEnterEvent(position: Offset(1.0, 401.0), device: 1),
const PointerHoverEvent(position: Offset(1.0, 401.0), device: 1),
]));
expect(_mouseTracker.mouseIsConnected, isTrue);
events.clear();
// First mouse hover
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 101.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerHoverEvent(position: Offset(0.0, 101.0)),
]));
expect(_mouseTracker.mouseIsConnected, isTrue);
events.clear();
// Second mouse hover
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(1.0, 501.0), device: 1),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerHoverEvent(position: Offset(1.0, 501.0), device: 1),
]));
expect(_mouseTracker.mouseIsConnected, isTrue);
events.clear();
// First mouse remove
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.remove, const Offset(0.0, 101.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerExitEvent(position: Offset(0.0, 101.0)),
]));
expect(_mouseTracker.mouseIsConnected, isTrue);
events.clear();
// Second mouse hover
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(1.0, 601.0), device: 1),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerHoverEvent(position: Offset(1.0, 601.0), device: 1),
]));
expect(_mouseTracker.mouseIsConnected, isTrue);
events.clear();
// Second mouse remove
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.remove, const Offset(1.0, 601.0), device: 1),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerExitEvent(position: Offset(1.0, 601.0), device: 1),
]));
expect(_mouseTracker.mouseIsConnected, isFalse);
events.clear();
});
test('detects exit when annotated layer no longer hit', () {
final ui.PointerDataPacket packet1 = ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 0.0)),
_pointerData(PointerChange.hover, const Offset(1.0, 101.0)),
]);
final ui.PointerDataPacket packet2 = ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(1.0, 201.0)),
]);
isInHitRegionOne = true;
RendererBinding.instance.mouseTracker.attachAnnotation(annotation);
test('should handle detaching during the callback of exiting', () {
bool isInHitRegion;
final List<PointerEvent> events = <PointerEvent>[];
final MouseTrackerAnnotation annotation = MouseTrackerAnnotation(
onEnter: (PointerEnterEvent event) => events.add(event),
onHover: (PointerHoverEvent event) => events.add(event),
onExit: (PointerExitEvent event) => events.add(event),
);
_setUpMouseAnnotationFinder((Offset position) sync* {
if (isInHitRegion) {
yield annotation;
}
});
ui.window.onPointerDataPacket(packet1);
isInHitRegion = true;
_mouseTracker.attachAnnotation(annotation);
// Enter
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(1.0, 0.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerEnterEvent(position: Offset(0.0, 0.0)),
const PointerHoverEvent(position: Offset(0.0, 0.0)),
const PointerHoverEvent(position: Offset(1.0, 101.0)),
const PointerEnterEvent(position: Offset(1.0, 0.0)),
const PointerHoverEvent(position: Offset(1.0, 0.0)),
]));
// Simulate layer going away by detaching it.
clear();
isInHitRegionOne = false;
expect(_mouseTracker.mouseIsConnected, isTrue);
events.clear();
ui.window.onPointerDataPacket(packet2);
// Remove
_mouseTracker.addListener(() {
if (!_mouseTracker.mouseIsConnected) {
_mouseTracker.detachAnnotation(annotation);
isInHitRegion = false;
}
});
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.remove, const Offset(1.0, 0.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerExitEvent(position: Offset(1.0, 201.0)),
const PointerExitEvent(position: Offset(1.0, 0.0)),
]));
expect(_mouseTracker.mouseIsConnected, isFalse);
events.clear();
});
// Actually detach annotation. Shouldn't receive hit.
RendererBinding.instance.mouseTracker.detachAnnotation(annotation);
clear();
isInHitRegionOne = false;
test('should not handle non-hover events', () {
final List<PointerEvent> events = <PointerEvent>[];
_setUpWithOneAnnotation(logEvents: events);
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.down, const Offset(0.0, 101.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
// This Enter event is triggered by the [PointerAddedEvent] that was
// synthesized during the event normalization of pointer event converter.
// The [PointerDownEvent] is ignored by [MouseTracker].
const PointerEnterEvent(position: Offset(0.0, 101.0)),
]));
events.clear();
ui.window.onPointerDataPacket(packet2);
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.move, const Offset(0.0, 201.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
]));
events.clear();
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.up, const Offset(0.0, 301.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
]));
events.clear();
});
test("don't flip out if not all mouse events are listened to", () {
test('should detect enter or exit when annotations are attached or detached on the pointer', () {
bool isInHitRegion;
final List<PointerEvent> events = <PointerEvent>[];
final MouseTrackerAnnotation annotation = MouseTrackerAnnotation(
onEnter: (PointerEnterEvent event) => events.add(event),
onHover: (PointerHoverEvent event) => events.add(event),
onExit: (PointerExitEvent event) => events.add(event),
);
_setUpMouseAnnotationFinder((Offset position) sync* {
if (isInHitRegion) {
yield annotation;
}
});
isInHitRegion = false;
// Connect a mouse when there is no annotation
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.add, const Offset(0.0, 100.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
]));
expect(_mouseTracker.mouseIsConnected, isTrue);
events.clear();
// Attach an annotation
isInHitRegion = true;
_mouseTracker.attachAnnotation(annotation);
// No callbacks are triggered immediately
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
]));
expect(_binding.postFrameCallbacks, hasLength(1));
_binding.flushPostFrameCallbacks(Duration.zero);
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerEnterEvent(position: Offset(0.0, 100.0)),
]));
events.clear();
// Detach the annotation
isInHitRegion = false;
_mouseTracker.detachAnnotation(annotation);
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerExitEvent(position: Offset(0.0, 100.0)),
]));
expect(_binding.postFrameCallbacks, hasLength(0));
});
test('should correctly stay quiet when annotations are attached or detached not on the pointer', () {
final List<PointerEvent> events = <PointerEvent>[];
final MouseTrackerAnnotation annotation = MouseTrackerAnnotation(
onEnter: (PointerEnterEvent event) => events.add(event),
onHover: (PointerHoverEvent event) => events.add(event),
onExit: (PointerExitEvent event) => events.add(event),
);
_setUpMouseAnnotationFinder((Offset position) sync* {
// This annotation is never in the region
});
// Connect a mouse when there is no annotation
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.add, const Offset(0.0, 100.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
]));
expect(_mouseTracker.mouseIsConnected, isTrue);
events.clear();
// Attach an annotation out of region
_mouseTracker.attachAnnotation(annotation);
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
]));
expect(_binding.postFrameCallbacks, hasLength(1));
_binding.flushPostFrameCallbacks(Duration.zero);
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
]));
events.clear();
// Detach the annotation
_mouseTracker.detachAnnotation(annotation);
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
]));
expect(_binding.postFrameCallbacks, hasLength(0));
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.remove, const Offset(0.0, 100.0)),
]));
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
]));
});
test('should not flip out if not all mouse events are listened to', () {
bool isInHitRegionOne = true;
bool isInHitRegionTwo = false;
final MouseTrackerAnnotation annotation1 = MouseTrackerAnnotation(
onEnter: (PointerEnterEvent event) {}
);
final MouseTrackerAnnotation annotation2 = MouseTrackerAnnotation(
onExit: (PointerExitEvent event) {}
);
_setUpMouseAnnotationFinder((Offset position) sync* {
if (isInHitRegionOne)
yield annotation1;
else if (isInHitRegionTwo)
yield annotation2;
});
final ui.PointerDataPacket packet = ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(1.0, 101.0)),
]);
isInHitRegionOne = false;
isInHitRegionTwo = true;
RendererBinding.instance.mouseTracker.attachAnnotation(partialAnnotation);
_mouseTracker.attachAnnotation(annotation2);
ui.window.onPointerDataPacket(packet);
RendererBinding.instance.mouseTracker.detachAnnotation(partialAnnotation);
_mouseTracker.detachAnnotation(annotation2);
isInHitRegionTwo = false;
// Passes if no errors are thrown
});
test('detects exit when mouse goes away', () {
final ui.PointerDataPacket packet1 = ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 0.0)),
_pointerData(PointerChange.hover, const Offset(1.0, 101.0)),
]);
final ui.PointerDataPacket packet2 = ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.remove, const Offset(1.0, 201.0)),
]);
isInHitRegionOne = true;
RendererBinding.instance.mouseTracker.attachAnnotation(annotation);
ui.window.onPointerDataPacket(packet1);
ui.window.onPointerDataPacket(packet2);
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerEnterEvent(position: Offset(0.0, 0.0)),
const PointerHoverEvent(position: Offset(0.0, 0.0)),
const PointerHoverEvent(position: Offset(1.0, 101.0)),
const PointerHoverEvent(position: Offset(1.0, 201.0)),
const PointerExitEvent(position: Offset(1.0, 201.0)),
test('should not call annotationFinder when no annotations are attached', () {
final MouseTrackerAnnotation annotation = MouseTrackerAnnotation(
onEnter: (PointerEnterEvent event) {},
);
int finderCalled = 0;
_setUpMouseAnnotationFinder((Offset position) sync* {
finderCalled++;
// This annotation is never in the region
});
// When no annotations are attached, hovering should not call finder.
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 101.0)),
]));
expect(finderCalled, 0);
// Attaching should call finder during the post frame.
_mouseTracker.attachAnnotation(annotation);
expect(finderCalled, 0);
_binding.flushPostFrameCallbacks(Duration.zero);
expect(finderCalled, 1);
finderCalled = 0;
// When annotations are attached, hovering should call finder.
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 201.0)),
]));
expect(finderCalled, 1);
finderCalled = 0;
// Detaching an annotation should not call finder (because only history
// records are needed).
_mouseTracker.detachAnnotation(annotation);
expect(finderCalled, 0);
// When all annotations are detached, hovering should not call finder.
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 201.0)),
]));
expect(finderCalled, 0);
});
test('handles mouse down and move', () {
final ui.PointerDataPacket packet1 = ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 0.0)),
_pointerData(PointerChange.hover, const Offset(1.0, 101.0)),
]);
final ui.PointerDataPacket packet2 = ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.down, const Offset(1.0, 101.0)),
_pointerData(PointerChange.move, const Offset(1.0, 201.0)),
]);
isInHitRegionOne = true;
RendererBinding.instance.mouseTracker.attachAnnotation(annotation);
ui.window.onPointerDataPacket(packet1);
ui.window.onPointerDataPacket(packet2);
expect(events, _equalToEventsOnCriticalFields(<PointerEvent>[
const PointerEnterEvent(position: Offset(0.0, 0.0), delta: Offset(0.0, 0.0)),
const PointerHoverEvent(position: Offset(0.0, 0.0), delta: Offset(0.0, 0.0)),
const PointerHoverEvent(position: Offset(1.0, 101.0), delta: Offset(1.0, 101.0)),
test('should trigger callbacks between parents and children in correct order', () {
// This test simulates the scenario of a layer being the child of another.
//
// ———————————
// |A |
// | —————— |
// | |B | |
// | —————— |
// ———————————
bool isInB;
final List<String> logs = <String>[];
final MouseTrackerAnnotation annotationA = MouseTrackerAnnotation(
onEnter: (PointerEnterEvent event) => logs.add('enterA'),
onExit: (PointerExitEvent event) => logs.add('exitA'),
onHover: (PointerHoverEvent event) => logs.add('hoverA'),
);
final MouseTrackerAnnotation annotationB = MouseTrackerAnnotation(
onEnter: (PointerEnterEvent event) => logs.add('enterB'),
onExit: (PointerExitEvent event) => logs.add('exitB'),
onHover: (PointerHoverEvent event) => logs.add('hoverB'),
);
_setUpMouseAnnotationFinder((Offset position) sync* {
// Children's annotations come before parents'
if (isInB) {
yield annotationB;
yield annotationA;
}
});
_mouseTracker.attachAnnotation(annotationA);
_mouseTracker.attachAnnotation(annotationB);
// Starts out of A
isInB = false;
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 1.0)),
]));
expect(logs, <String>[]);
// Moves into B within one frame
isInB = true;
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 10.0)),
]));
expect(logs, <String>['enterA', 'enterB', 'hoverA', 'hoverB']);
logs.clear();
// Moves out of A within one frame
isInB = false;
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 20.0)),
]));
expect(logs, <String>['exitB', 'exitA']);
});
test('should trigger callbacks between disjoint siblings in correctly order', () {
// This test simulates the scenario of 2 sibling layers that do not overlap
// with each other.
//
// ———————— ————————
// |A | |B |
// | | | |
// ———————— ————————
bool isInA;
bool isInB;
final List<String> logs = <String>[];
final MouseTrackerAnnotation annotationA = MouseTrackerAnnotation(
onEnter: (PointerEnterEvent event) => logs.add('enterA'),
onExit: (PointerExitEvent event) => logs.add('exitA'),
onHover: (PointerHoverEvent event) => logs.add('hoverA'),
);
final MouseTrackerAnnotation annotationB = MouseTrackerAnnotation(
onEnter: (PointerEnterEvent event) => logs.add('enterB'),
onExit: (PointerExitEvent event) => logs.add('exitB'),
onHover: (PointerHoverEvent event) => logs.add('hoverB'),
);
_setUpMouseAnnotationFinder((Offset position) sync* {
if (isInA) {
yield annotationA;
} else if (isInB) {
yield annotationB;
}
});
_mouseTracker.attachAnnotation(annotationA);
_mouseTracker.attachAnnotation(annotationB);
// Starts within A
isInA = true;
isInB = false;
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 1.0)),
]));
expect(logs, <String>['enterA', 'hoverA']);
logs.clear();
// Moves into B within one frame
isInA = false;
isInB = true;
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 10.0)),
]));
expect(logs, <String>['exitA', 'enterB', 'hoverB']);
logs.clear();
// Moves into A within one frame
isInA = true;
isInB = false;
ui.window.onPointerDataPacket(ui.PointerDataPacket(data: <ui.PointerData>[
_pointerData(PointerChange.hover, const Offset(0.0, 1.0)),
]));
expect(logs, <String>['exitB', 'enterA', 'hoverA']);
});
}
......
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