RendererBinding mixin Null safety

The glue between the render tree and the Flutter engine.

Superclass Constraints
Mixin Applications


mouseTracker MouseTracker
The object that manages state about currently connected mice, for hover notification.
pipelineOwner PipelineOwner
The render tree's owner, which maintains dirty state for layout, composite, paint, and accessibility semantics.
renderView RenderView
The render tree that's attached to the output surface.
read / write
sendFramesToEngine bool
Whether frames produced by drawFrame are sent to the engine.
window SingletonFlutterWindow
The main window to which this binding is bound.
read-only, inherited
platformDispatcher PlatformDispatcher
The ui.PlatformDispatcher to which this binding is bound.
read-only, inherited
locked bool
Whether lockEvents is currently locking events.
@protected, read-only, inherited
hashCode int
The hash code for this object.
read-only, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited
keyboard HardwareKeyboard
The global singleton instance of HardwareKeyboard, which can be used to query keyboard states.
read-only, inherited
keyEventManager KeyEventManager
The global singleton instance of KeyEventManager, which is used internally to dispatch key messages.
read-only, inherited
defaultBinaryMessenger BinaryMessenger
The default instance of BinaryMessenger.
read-only, inherited
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.
read-only, inherited
restorationManager RestorationManager
The RestorationManager synchronizes the restoration data between engine and framework.
read-only, inherited
schedulingStrategy SchedulingStrategy
The strategy to use when deciding whether to run a task or not.
read / write, inherited
lifecycleState AppLifecycleState?
Whether the application is visible, and if so, whether it is currently interactive.
read-only, inherited
transientCallbackCount int
The current number of transient frame callbacks scheduled.
read-only, inherited
endOfFrame Future<void>
Returns a Future that completes after the frame completes.
read-only, inherited
hasScheduledFrame bool
Whether this scheduler has requested that handleBeginFrame be called soon.
read-only, inherited
schedulerPhase SchedulerPhase
The phase that the scheduler is currently operating under.
read-only, inherited
framesEnabled bool
Whether frames are currently being scheduled when scheduleFrame is called.
read-only, inherited
currentFrameTimeStamp Duration
The time stamp for the frame currently being processed.
read-only, inherited
currentSystemFrameTimeStamp Duration
The raw time stamp as provided by the engine to dart:ui.PlatformDispatcher.onBeginFrame for the frame currently being processed.
read-only, inherited
pointerRouter PointerRouter
A router that routes all pointer events received from the engine.
final, inherited
gestureArena GestureArenaManager
The gesture arenas used for disambiguating the meaning of sequences of pointer events.
final, inherited
pointerSignalResolver PointerSignalResolver
The resolver used for determining which widget handles a PointerSignalEvent.
final, inherited
resamplingEnabled bool
Enable pointer event resampling for touch devices by setting this to true.
read / write, inherited
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.
read / write, inherited
debugSamplingClock SamplingClock?
Overrides the sampling clock for debugging and testing.
@protected, read-only, inherited
accessibilityFeatures AccessibilityFeatures
The currently active set of AccessibilityFeatures.
read-only, inherited
disableAnimations bool
The platform is requesting that animations be disabled or simplified.
read-only, inherited


addPersistentFrameCallback(FrameCallback callback) → void
Adds a persistent frame callback.
addPostFrameCallback(FrameCallback callback) → void
Schedule a callback for the end of this frame.
addTimingsCallback(TimingsCallback callback) → void
Add a TimingsCallback that receives FrameTiming sent from the engine.
allowFirstFrame() → void
Called after deferFirstFrame to tell the framework that it is ok to send the first frame to the engine now.
cancelFrameCallbackWithId(int id) → void
Cancels the transient frame callback with the given id.
cancelPointer(int pointer) → void
Dispatch a PointerCancelEvent for the given pointer soon.
createBinaryMessenger() BinaryMessenger
Creates a default BinaryMessenger instance that can be used for sending platform messages.
@protected, inherited
createRestorationManager() RestorationManager
Creates the RestorationManager instance available via restorationManager.
@protected, inherited
createSemanticsUpdateBuilder() SemanticsUpdateBuilder
Creates an empty semantics update builder.
createViewConfiguration() ViewConfiguration
Returns a ViewConfiguration configured for the RenderView based on the current environment.
debugAssertNoTransientCallbacks(String reason) bool
Asserts that there are no registered transient callbacks; if there are, prints their locations and throws an exception.
deferFirstFrame() → void
Tell the framework to not send the first frames to the engine until there is a corresponding call to allowFirstFrame.
dispatchEvent(PointerEvent event, HitTestResult? hitTestResult) → void
Dispatch an event to pointerRouter and the path of a hit test result.
drawFrame() → void
Pump the rendering pipeline to generate a frame.
ensureFrameCallbacksRegistered() → void
Ensures callbacks for PlatformDispatcher.onBeginFrame and PlatformDispatcher.onDrawFrame are registered.
@protected, inherited
ensureVisualUpdate() → void
Schedules a new frame using scheduleFrame if this object is not currently producing a frame.
evict(String asset) → void
Called in response to the ext.flutter.evict service extension.
@mustCallSuper, @protected, inherited
handleAccessibilityFeaturesChanged() → void
Called when the platform accessibility features change.
@protected, inherited
handleAppLifecycleStateChanged(AppLifecycleState state) → void
Called when the application lifecycle state changes.
@mustCallSuper, @protected, inherited
handleBeginFrame(Duration? rawTimeStamp) → void
Called by the engine to prepare the framework to produce a new frame.
handleDrawFrame() → void
Called by the engine to produce a new frame.
handleEvent(PointerEvent event, HitTestEntry<HitTestTarget> entry) → void
Override this method to receive events.
handleEventLoopCallback() bool
Execute the highest-priority task, if it is of a high enough priority.
@visibleForTesting, inherited
handleMemoryPressure() → void
Called when the operating system notifies the application of a memory pressure situation.
@mustCallSuper, @protected, inherited
handleMetricsChanged() → void
Called when the system metrics change.
handlePlatformBrightnessChanged() → void
Called when the platform brightness changes.
handlePointerEvent(PointerEvent event) → void
Dispatch an event to the targets found by a hit test on its position.
handleSystemMessage(Object systemMessage) Future<void>
Handler called for messages received on the SystemChannels.system message channel.
@mustCallSuper, @protected, inherited
handleTextScaleFactorChanged() → void
Called when the platform text scale factor changes.
hitTest(HitTestResult result, Offset position) → void
Determine which HitTestTarget objects are located at a given position.
initInstances() → void
The initialization method. Subclasses override this method to hook into the platform and otherwise configure their services. Subclasses must call "super.initInstances()".
initLicenses() → void
Adds relevant licenses to the LicenseRegistry.
@mustCallSuper, @protected, inherited
initMouseTracker([MouseTracker? tracker]) → void
Creates a MouseTracker which manages state about currently connected mice, for hover notification.
initRenderView() → void
Creates a RenderView object to be the root of the RenderObject rendering tree, and initializes it so that it will be rendered when the next frame is requested.
initServiceExtensions() → void
Called when the binding is initialized, to register service extensions.
lockEvents(Future<void> callback()) Future<void>
Locks the dispatching of asynchronous events and callbacks until the callback's future completes.
@protected, inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
performReassemble() Future<void>
This method is called by reassembleApplication to actually cause the application to reassemble, e.g. after a hot reload.
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.
@protected, inherited
readInitialLifecycleStateFromNativeWindow() → void
Initializes the lifecycleState with the dart:ui.PlatformDispatcher.initialLifecycleState.
@protected, inherited
reassembleApplication() Future<void>
Cause the entire application to redraw, e.g. after a hot reload.
registerBoolServiceExtension({required String name, required AsyncValueGetter<bool> getter, required AsyncValueSetter<bool> setter}) → void
Registers a service extension method with the given name (full 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.)
@protected, 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 ""), 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.)
@protected, inherited
registerServiceExtension({required String name, required ServiceExtensionCallback callback}) → void
Registers a service extension method with the given name (full name "").
@protected, inherited
registerSignalServiceExtension({required String name, required AsyncCallback callback}) → void
Registers a service extension method with the given name (full name ""), which takes no arguments and returns no value.
@protected, 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 ""), 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.
@protected, inherited
removeTimingsCallback(TimingsCallback callback) → void
Removes a callback that was earlier added by addTimingsCallback.
resetEpoch() → void
Prepares the scheduler for a non-monotonic change to how time stamps are calculated.
resetFirstFrameSent() → void
Call this to pretend that no frames have been sent to the engine yet.
resetGestureBinding() → void
Reset states of GestureBinding.
@protected, inherited
scheduleForcedFrame() → void
Schedules a new frame by calling dart:ui.PlatformDispatcher.scheduleFrame.
scheduleFrame() → void
If necessary, schedules a new frame by calling dart:ui.PlatformDispatcher.scheduleFrame.
scheduleFrameCallback(FrameCallback callback, {bool rescheduling = false}) int
Schedules the given transient frame callback.
scheduleTask<T>(TaskCallback<T> task, Priority priority, {String? debugLabel, Flow? flow}) Future<T>
Schedules the given task with the given priority and returns a Future that completes to the task's eventual return value.
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.
setSemanticsEnabled(bool enabled) → void
Whether the render tree associated with this binding should produce a tree of SemanticsNode objects.
setSystemUiChangeCallback(SystemUiChangeCallback? callback) → void
Sets the callback for the SystemChrome.systemUIChange method call received on the SystemChannels.platform channel.
toString() String
A string representation of this object.
unlocked() → void
Called by lockEvents when events get unlocked.
@mustCallSuper, @protected, inherited


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

Static Properties

instance RendererBinding
The current RendererBinding, if one has been created.
read-only, override