SchedulerBinding mixin Null safety

Scheduler for running the following:

  • Transient callbacks, triggered by the system's Window.onBeginFrame callback, for synchronizing the application's behavior to the system's display. For example, Tickers and AnimationControllers trigger from these.

  • Persistent callbacks, triggered by the system's Window.onDrawFrame callback, for updating the system's display after transient callbacks have executed. For example, the rendering layer uses this to drive its rendering pipeline.

  • Post-frame callbacks, which are run after persistent callbacks, just before returning from the Window.onDrawFrame callback.

  • Non-rendering tasks, to be run between frames. These are given a priority and are executed in priority order according to a schedulingStrategy.

Superclass Constraints
Implemented by

Constructors

SchedulerBinding()

Properties

schedulingStrategy SchedulingStrategy
The strategy to use when deciding whether to run a task or not. [...]
read / write
lifecycleState AppLifecycleState?
Whether the application is visible, and if so, whether it is currently interactive. [...]
read-only
transientCallbackCount int
The current number of transient frame callbacks scheduled. [...]
read-only
endOfFrame Future<void>
Returns a Future that completes after the frame completes. [...]
read-only
hasScheduledFrame bool
Whether this scheduler has requested that handleBeginFrame be called soon.
read-only
schedulerPhase SchedulerPhase
The phase that the scheduler is currently operating under.
read-only
framesEnabled bool
Whether frames are currently being scheduled when scheduleFrame is called. [...]
read-only
currentFrameTimeStamp Duration
The time stamp for the frame currently being processed. [...]
read-only
currentSystemFrameTimeStamp Duration
The raw time stamp as provided by the engine to Window.onBeginFrame for the frame currently being processed. [...]
read-only
window Window
The window 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

Methods

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
addTimingsCallback(TimingsCallback callback) → void
Add a TimingsCallback that receives FrameTiming sent from the engine. [...]
removeTimingsCallback(TimingsCallback callback) → void
Removes a callback that was earlier added by addTimingsCallback.
initServiceExtensions() → void
Called when the binding is initialized, to register service extensions. [...]
override
handleAppLifecycleStateChanged(AppLifecycleState state) → void
Called when the application lifecycle state changes. [...]
@mustCallSuper, @protected
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. [...]
unlocked() → void
Called by lockEvents when events get unlocked. [...]
override
handleEventLoopCallback() bool
Execute the highest-priority task, if it is of a high enough priority. [...]
@visibleForTesting
scheduleFrameCallback(FrameCallback callback, {bool rescheduling: false}) int
Schedules the given transient frame callback. [...]
cancelFrameCallbackWithId(int id) → void
Cancels the transient frame callback with the given id. [...]
debugAssertNoTransientCallbacks(String reason) bool
Asserts that there are no registered transient callbacks; if there are, prints their locations and throws an exception. [...]
addPersistentFrameCallback(FrameCallback callback) → void
Adds a persistent frame callback. [...]
addPostFrameCallback(FrameCallback callback) → void
Schedule a callback for the end of this frame. [...]
ensureFrameCallbacksRegistered() → void
Ensures callbacks for window.onBeginFrame and window.onDrawFrame are registered.
@protected
ensureVisualUpdate() → void
Schedules a new frame using scheduleFrame if this object is not currently producing a frame. [...]
scheduleFrame() → void
If necessary, schedules a new frame by calling Window.scheduleFrame. [...]
scheduleForcedFrame() → void
Schedules a new frame by calling Window.scheduleFrame. [...]
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. [...]
resetEpoch() → void
Prepares the scheduler for a non-monotonic change to how time stamps are calculated. [...]
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. [...]
lockEvents(Future<void> callback()) Future<void>
Locks the dispatching of asynchronous events and callbacks until the callback's future completes. [...]
@protected, inherited
reassembleApplication() Future<void>
Cause the entire application to redraw, e.g. after a hot reload. [...]
inherited
performReassemble() Future<void>
This method is called by reassembleApplication to actually cause the application to reassemble, e.g. after a hot reload. [...]
@mustCallSuper, @protected, 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. [...]
@protected, 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.) [...]
@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 "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.) [...]
@protected, 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.
@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 "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. [...]
@protected, inherited
registerServiceExtension({required String name, required ServiceExtensionCallback callback}) → void
Registers a service extension method with the given name (full name "ext.flutter.name"). [...]
@protected, inherited
toString() String
Returns a string representation of this object.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
inherited

Operators

operator ==(Object other) bool
The equality operator. [...]
inherited

Static Properties

instance SchedulerBinding?
The current SchedulerBinding, if one has been created.
read-only

Static Methods

debugPrintTransientCallbackRegistrationStack() → void
Prints the stack for where the current transient callback was registered. [...]