ElementsBinding mixin

The glue between the elements layer and the Flutter engine.

Superclass constraints
Mixin applications

Properties

accessibilityFeatures → AccessibilityFeatures
The currently active set of ui.AccessibilityFeatures.
no setterinherited
accessibilityFocus → ValueNotifier<int?>
Listenable that notifies when the accessibility focus on the system have changed.
finalinherited
channelBuffers → ChannelBuffers
The low level buffering and dispatch mechanism for messages sent by plugins on the engine side to their corresponding plugin code on the framework side.
no setterinherited
currentFrameTimeStamp → Duration
The time stamp for the frame currently being processed.
no setterinherited
currentSystemFrameTimeStamp → Duration
The raw time stamp as provided by the engine to dart:ui.PlatformDispatcher.onBeginFrame for the frame currently being processed.
no setterinherited
debugDidSendFirstFrameEvent → bool
Whether the first frame has finished building.
no setter
debugOutstandingSemanticsHandles → int
The number of clients registered to listen for semantics.
no setterinherited
debugSamplingClock → SamplingClock?
Overrides the sampling clock for debugging and testing.
no setterinherited
defaultBinaryMessenger → BinaryMessenger
The default instance of BinaryMessenger.
no setterinherited
disableAnimations → bool
The platform is requesting that animations be disabled or simplified.
no setterinherited
endOfFrame → Future<void>
Returns a Future that completes after the frame completes.
no setterinherited
firstFrameRasterized → bool
Whether the Flutter engine has rasterized the first frame.
no setter
framesEnabled → bool
Whether frames are currently being scheduled when scheduleFrame is called.
no setterinherited
gestureArena → GestureArenaManager
The gesture arenas used for disambiguating the meaning of sequences of pointer events.
finalinherited
hashCode → int
The hash code for this object.
no setterinherited
hasScheduledFrame → bool
Whether this scheduler has requested that handleBeginFrame be called soon.
no setterinherited
keyboard → HardwareKeyboard
The global singleton instance of HardwareKeyboard, which can be used to query keyboard states.
no setterinherited
keyEventManager → KeyEventManager
The global singleton instance of KeyEventManager, which is used internally to dispatch key messages.
no setterinherited
lifecycleState → AppLifecycleState?
Whether the application is visible, and if so, whether it is currently interactive.
no setterinherited
locked → bool
Whether lockEvents is currently locking events.
no setterinherited
mouseTracker → MouseTracker
The object that manages state about currently connected mice, for hover notification.
no setterinherited
pipelineOwner → PipelineOwner
Deprecated. Will be removed in a future version of Flutter.
latefinalinherited
platformDispatcher → PlatformDispatcher
The ui.PlatformDispatcher to which this binding is bound.
no setterinherited
pointerRouter → PointerRouter
A router that routes all pointer events received from the engine.
finalinherited
pointerSignalResolver → PointerSignalResolver
The resolver used for determining which widget handles a PointerSignalEvent.
finalinherited
renderView → RenderView
Deprecated. Will be removed in a future version of Flutter.
latefinalinherited
renderViews → Iterable<RenderView>
The RenderViews managed by this binding.
no setterinherited
resamplingEnabled ↔ bool
Enable pointer event resampling for touch devices by setting this to true.
getter/setter pairinherited
restorationManager → RestorationManager
The RestorationManager synchronizes the restoration data between engine and framework.
no setterinherited
rootPipelineOwner → PipelineOwner
The PipelineOwner that is the root of the PipelineOwner tree.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
samplingClock → SamplingClock
Provides access to the current DateTime and StopWatch objects for sampling.
no setterinherited
samplingOffset ↔ Duration
Offset relative to current frame time that should be used for resampling. The samplingOffset is expected to be negative. Non-negative samplingOffset is allowed but will effectively disable resampling.
getter/setter pairinherited
schedulerPhase → SchedulerPhase
The phase that the scheduler is currently operating under.
no setterinherited
schedulingStrategy ↔ SchedulingStrategy
The strategy to use when deciding whether to run a task or not.
getter/setter pairinherited
semanticsEnabled → bool
Whether semantics information must be collected.
no setterinherited
sendFramesToEngine → bool
Whether frames produced by drawFrame are sent to the engine.
no setterinherited
transientCallbackCount → int
The current number of transient frame callbacks scheduled.
no setterinherited
waitUntilFirstFrameRasterized → Future<void>
A future that completes when the Flutter engine has rasterized the first frame.
no setter
window → SingletonFlutterWindow
Deprecated. Will be removed in a future version of Flutter.
no setterinherited

Methods

addObserver(ElementsBindingObserver observer) → void
Registers the given object as a binding observer. Binding observers are notified when various application events occur, for example when the system locale changes. Generally, one element in the element tree registers itself as a binding observer, and converts the system state into inherited elements.
addPersistentFrameCallback(FrameCallback callback) → void
Adds a persistent frame callback.
inherited
addPostFrameCallback(FrameCallback callback, {String debugLabel = 'callback'}) → void
Schedule a callback for the end of this frame.
inherited
addRenderView(RenderView view) → void
Adds a RenderView to this binding.
inherited
addSemanticsEnabledListener(VoidCallback listener) → void
Adds a listener to be called when semanticsEnabled changes.
inherited
addTimingsCallback(TimingsCallback callback) → void
Add a TimingsCallback that receives FrameTiming sent from the engine.
inherited
allowFirstFrame() → void
Called after deferFirstFrame to tell the framework that it is ok to send the first frame to the engine now.
inherited
allowFirstFrameReport() → void
When called after deferFirstFrameReport: tell the framework to report the frame it is building as a "useful" first frame.
cancelFrameCallbackWithId(int id) → void
Cancels the transient frame callback with the given id.
inherited
cancelPointer(int pointer) → void
Dispatch a PointerCancelEvent for the given pointer soon.
inherited
createBinaryMessenger() → BinaryMessenger
Creates a default BinaryMessenger instance that can be used for sending platform messages.
inherited
createCanvas(PictureRecorder recorder) → Canvas
Create a Canvas from a PictureRecorder.
inherited
createPictureRecorder() → PictureRecorder
Create a PictureRecorder.
inherited
createRestorationManager() → RestorationManager
Creates the RestorationManager instance available via restorationManager.
inherited
createRootPipelineOwner() → PipelineOwner
Creates the PipelineOwner that serves as the root of the pipeline owner tree (rootPipelineOwner).
inherited
createSceneBuilder() → SceneBuilder
Create a SceneBuilder.
inherited
createSemanticsUpdateBuilder() → SemanticsUpdateBuilder
Creates an empty semantics update builder.
inherited
createViewConfigurationFor(RenderView renderView) → ViewConfiguration
Returns a ViewConfiguration configured for the provided RenderView based on the current environment.
inherited
debugAssertNoPendingPerformanceModeRequests(String reason) → bool
Asserts that there are no pending performance mode requests in debug mode.
inherited
debugAssertNoTimeDilation(String reason) → bool
Asserts that there is no artificial time dilation in debug mode.
inherited
debugAssertNoTransientCallbacks(String reason) → bool
Asserts that there are no registered transient callbacks; if there are, prints their locations and throws an exception.
inherited
debugCheckZone(String entryPoint) → bool
Checks that the current Zone is the same as that which was used to initialize the binding.
inherited
debugGetRequestedPerformanceMode() → DartPerformanceMode?
Returns the current DartPerformanceMode requested or null if no requests have been made.
inherited
deferFirstFrame() → void
Tell the framework to not send the first frames to the engine until there is a corresponding call to allowFirstFrame.
inherited
deferFirstFrameReport() → void
Tell the framework not to report the frame it is building as a "useful" first frame until there is a corresponding call to allowFirstFrameReport.
dispatchAccessibilityFeaturesChanged() → void
Notify all the observers that the active set of AccessibilityFeatures has changed (using ElementsBindingObserver.didChangeAccessibilityFeatures), giving them the features argument.
dispatchEvent(PointerEvent event, HitTestResult? hitTestResult) → void
Dispatch an event to pointerRouter and the path of a hit test result.
inherited
dispatchLocalesChanged(List<Locale> locales) → void
Notify all the observers that the locale has changed (using ElementsBindingObserver.didChangeLocales), giving them the locales argument.
drawFrame() → void
Pump the rendering pipeline to generate a frame.
inherited
ensureFrameCallbacksRegistered() → void
Ensures callbacks for PlatformDispatcher.onBeginFrame and PlatformDispatcher.onDrawFrame are registered.
inherited
ensureSemantics() → SemanticsHandle
Creates a new SemanticsHandle and requests the collection of semantics information.
inherited
ensureVisualUpdate() → void
Schedules a new frame using scheduleFrame if this object is not currently producing a frame.
inherited
evict(String asset) → void
Called in response to the ext.flutter.evict service extension.
inherited
exitApplication(AppExitType exitType, [int exitCode = 0]) → Future<AppExitResponse>
Exits the application by calling the native application API method for exiting an application cleanly.
inherited
handleAccessibilityFeaturesChanged() → void
Called when the platform accessibility features change.
override
handleAppLifecycleStateChanged(AppLifecycleState state) → void
Called when the application lifecycle state changes.
override
handleBeginFrame(Duration? rawTimeStamp) → void
Called by the engine to prepare the framework to produce a new frame.
inherited
handleDrawFrame() → void
Called by the engine to produce a new frame.
inherited
handleEvent(PointerEvent event, HitTestEntry<HitTestTarget> entry) → void
Override this method to receive events.
inherited
handleEventLoopCallback() → bool
Execute the highest-priority task, if it is of a high enough priority.
inherited
handleLocaleChanged() → void
Called when the system locale changes.
handleMemoryPressure() → void
Called when the operating system notifies the application of a memory pressure situation.
override
handleMetricsChanged() → void
Called when the system metrics change.
override
handlePlatformBrightnessChanged() → void
Called when the platform brightness changes.
override
handlePointerEvent(PointerEvent event) → void
Dispatch an event to the targets found by a hit test on its position.
inherited
handlePopRoute() → Future<void>
Called when the system pops the current route.
handlePushRoute(String route) → Future<void>
Called when the host tells the app to push a new route onto the navigator.
handleRequestAppExit() → Future<AppExitResponse>
Handles any requests for application exit that may be received on the SystemChannels.platform method channel.
inherited
handleSystemMessage(Object systemMessage) → Future<void>
Handler called for messages received on the SystemChannels.system message channel.
override
handleTextScaleFactorChanged() → void
Called when the platform text scale factor changes.
override
handleViewFocusChanged(ViewFocusEvent event) → void
Called whenever the PlatformDispatcher receives a notification that the focus state on a view has changed.
inherited
hitTest(HitTestResult result, Offset position) → void
Deprecated. Use hitTestInView instead.
inherited
hitTestInView(HitTestResult result, Offset position, int viewId) → void
Determine which HitTestTarget objects are located at a given position in the specified view.
inherited
initializationComplete() → Future<void>
Alert the engine that the binding is registered. This instructs the engine to register its top level window handler on Windows. This signals that the app is able to process "System.requestAppExit" signals from the engine.
inherited
initInstances() → void
The initialization method. Subclasses override this method to hook into the platform and otherwise configure their services. Subclasses must call "super.initInstances()".
override
initLicenses() → void
Adds relevant licenses to the LicenseRegistry.
inherited
initMouseTracker([MouseTracker? tracker]) → void
Creates a MouseTracker which manages state about currently connected mice, for hover notification.
inherited
initServiceExtensions() → void
Called when the binding is initialized, to register service extensions.
override
lockEvents(Future<void> callback()) → Future<void>
Locks the dispatching of asynchronous events and callbacks until the callback's future completes.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
performReassemble() → Future<void>
This method is called by reassembleApplication to actually cause the application to reassemble, e.g. after a hot reload.
inherited
performSemanticsAction(SemanticsActionEvent action) → void
Called whenever the platform requests an action to be performed on a SemanticsNode.
inherited
postEvent(String eventKind, Map<String, dynamic> eventData) → void
All events dispatched by a BindingBase use this method instead of calling developer.postEvent directly so that tests for BindingBase can track which events were dispatched by overriding this method.
inherited
readInitialLifecycleStateFromNativeWindow() → void
Initializes the lifecycleState with the dart:ui.PlatformDispatcher.initialLifecycleState.
inherited
reassembleApplication() → Future<void>
Cause the entire application to redraw, e.g. after a hot reload.
inherited
registerBoolServiceExtension({required String name, required AsyncValueGetter<bool> getter, required AsyncValueSetter<bool> setter}) → void
Registers a service extension method with the given name (full name "ext.flutter.name"), which takes a single argument "enabled" which can have the value "true" or the value "false" or can be omitted to read the current value. (Any value other than "true" is considered equivalent to "false". Other arguments are ignored.)
inherited
registerNumericServiceExtension({required String name, required AsyncValueGetter<double> getter, required AsyncValueSetter<double> setter}) → void
Registers a service extension method with the given name (full name "ext.flutter.name"), which takes a single argument with the same name as the method which, if present, must have a value that can be parsed by double.parse, and can be omitted to read the current value. (Other arguments are ignored.)
inherited
registerServiceExtension({required String name, required ServiceExtensionCallback callback}) → void
Registers a service extension method with the given name (full name "ext.flutter.name").
inherited
registerSignalServiceExtension({required String name, required AsyncCallback callback}) → void
Registers a service extension method with the given name (full name "ext.flutter.name"), which takes no arguments and returns no value.
inherited
registerStringServiceExtension({required String name, required AsyncValueGetter<String> getter, required AsyncValueSetter<String> setter}) → void
Registers a service extension method with the given name (full name "ext.flutter.name"), which optionally takes a single argument with the name "value". If the argument is omitted, the value is to be read, otherwise it is to be set. Returns the current value.
inherited
removeObserver(ElementsBindingObserver observer) → bool
Unregisters the given observer. This should be used sparingly as it is relatively expensive (O(N) in the number of registered observers).
removeRenderView(RenderView view) → void
Removes a RenderView previously added with addRenderView from the binding.
inherited
removeSemanticsEnabledListener(VoidCallback listener) → void
Removes a listener added by addSemanticsEnabledListener.
inherited
removeTimingsCallback(TimingsCallback callback) → void
Removes a callback that was earlier added by addTimingsCallback.
inherited
requestPerformanceMode(DartPerformanceMode mode) → PerformanceModeRequestHandle?
Request a specific DartPerformanceMode.
inherited
resetEpoch() → void
Prepares the scheduler for a non-monotonic change to how time stamps are calculated.
inherited
resetFirstFrameSent() → void
Call this to pretend that no frames have been sent to the engine yet.
inherited
resetGestureBinding() → void
Reset states of GestureBinding.
inherited
resetInternalState() → void
Allows the test framework to reset the lifecycle state and framesEnabled back to their initial values.
inherited
scheduleForcedFrame() → void
Schedules a new frame by calling dart:ui.PlatformDispatcher.scheduleFrame.
inherited
scheduleFrame() → void
If necessary, schedules a new frame by calling dart:ui.PlatformDispatcher.scheduleFrame.
inherited
scheduleFrameCallback(FrameCallback callback, {bool rescheduling = false}) → int
Schedules the given transient frame callback.
inherited
scheduleTask<T>(TaskCallback<T> task, Priority priority, {String? debugLabel, Flow? flow}) → Future<T>
Schedules the given task with the given priority.
inherited
scheduleWarmUpFrame() → void
Schedule a frame to run as soon as possible, rather than waiting for the engine to request a frame in response to a system "Vsync" signal.
inherited
setSystemUiChangeCallback(SystemUiChangeCallback? callback) → void
Sets the callback for the SystemChrome.systemUIChange method call received on the SystemChannels.platform channel.
inherited
toString() → String
A string representation of this object.
inherited
unlocked() → void
Called by lockEvents when events get unlocked.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Static Properties

instance → ElementsBinding?
The current ElementsBinding, if one has been created.
no setter