ObservedPollingStreamService<TData extends Object> class abstract

An ObservedService that polls an external source on a fixed interval (via PollingStreamServiceMixin) and exposes it as a broadcast stream.

Inheritance
Mixed-in types

Properties

didEverInitAndSuccessfully → bool
true once init has completed successfully at least once for this service instance. Stays true even after a subsequent error or dispose.
no setterinherited
hashCode → int
The hash code for this object.
no setterinherited
initialData → Option<Resolvable<TData>>
Resolves with the first data point emitted on the stream after init. Becomes Some(Err) if the stream is stopped before any data arrives, so callers don't hang forever.
no setterinherited
isObserverRegistered → bool
Whether this service is currently registered as a WidgetsBindingObserver. Becomes true after registerObserver runs successfully and false after unregisterObserver.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
state → ServiceState
The current state of the service.
no setterinherited
stream → Option<Stream<Result<TData>>>
The broadcast stream of Result<TData> events. None before init and after dispose; otherwise wraps a broadcast controller's stream.
no setterinherited

Methods

didChangeAccessibilityFeatures() → void
Called when the system changes the set of currently active accessibility features.
inherited
didChangeAppLifecycleState(AppLifecycleState state) → void
Called when the system puts the app in the background or returns the app to the foreground.
inherited
didChangeLocales(List<Locale>? locales) → void
Called when the system tells the app that the user's locale has changed. For example, if the user changes the system language settings.
inherited
didChangeMetrics() → void
Called when the application's dimensions change. For example, when a phone is rotated.
inherited
didChangePlatformBrightness() → void
Called when the platform brightness changes.
inherited
didChangeTextScaleFactor() → void
Called when the platform's text scale factor changes.
inherited
didChangeViewFocus(ViewFocusEvent event) → void
Called whenever the PlatformDispatcher receives a notification that the focus state on a view has changed.
inherited
didHaveMemoryPressure() → void
Called when the system is running low on memory.
inherited
didPopRoute() → Future<bool>
Called when the system tells the app to pop the current route, such as after a system back button press or back gesture.
inherited
didPushRoute(String route) → Future<bool>
Called when the host tells the application to push a new route onto the navigator.
inherited
didPushRouteInformation(RouteInformation routeInformation) → Future<bool>
Called when the host tells the application to push a new RouteInformation and a restoration state onto the router.
inherited
didRequestAppExit() → Future<AppExitResponse>
Called when a request is received from the system to exit the application.
inherited
dispose({bool eagerError = false}) → Resolvable<Unit>
Drives the service into ServiceState.DISPOSE_SUCCESS by running listeners from provideDisposeListeners.
inherited
handleCancelBackGesture() → void
Called when a predictive back gesture is canceled, indicating that no navigation should occur.
inherited
handleCommitBackGesture() → void
Called when a predictive back gesture is finished successfully, indicating that the current route should be popped.
inherited
handleDetachedState() → bool
Return true to have the service dispose when the app enters AppLifecycleState.detached. Defaults to false (opt-in).
inherited
handleHiddenState() → bool
Return true to have the service pause when the app enters AppLifecycleState.hidden. Defaults to false (opt-in).
inherited
handleInactiveState() → bool
Return true to have the service pause when the app enters AppLifecycleState.inactive. Defaults to false (opt-in).
inherited
handlePausedState() → bool
Return true to have the service pause when the app enters AppLifecycleState.paused. Defaults to false (opt-in).
inherited
handleResumedState() → bool
Return true to have the service resume when the app enters AppLifecycleState.resumed. Defaults to false (opt-in).
inherited
handleStartBackGesture(PredictiveBackEvent backEvent) → bool
Called at the start of a predictive back gesture.
inherited
handleStatusBarTap() → void
Called when the user taps the status bar on iOS, to scroll a scroll view to the top.
inherited
handleUpdateBackGestureProgress(PredictiveBackEvent backEvent) → void
Called when a predictive back gesture moves.
inherited
init({bool eagerError = true}) → Resolvable<Unit>
Drives the service from ServiceState.NOT_INITIALIZED to ServiceState.RUN_SUCCESS by running every listener from provideInitListeners sequentially.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
onPoll() → Resolvable<TData>
Subclasses implement the actual polling call (fetch / read / refresh). Invoked once on subscription and then every providePollingInterval.
inherited
pause({bool eagerError = false}) → Resolvable<Unit>
Transitions the service into ServiceState.PAUSE_SUCCESS by running listeners from providePauseListeners.
inherited
provideDisposeListeners(void _) → TServiceResolvables<Unit>
Subclasses return the listeners to run when dispose is called. Mixins must call super.provideDisposeListeners(null) and prepend/append their own listeners (typically prepending teardown ahead of super's base cleanup).
override
provideInitListeners(void _) → TServiceResolvables<Unit>
Subclasses return the listeners to run when init is called. Mixins must call super.provideInitListeners(null) and prepend/append their own listeners.
override
provideInputStream() → TResultStream<TData>
Subclasses return the upstream input that feeds this service. Called once per restartStream / init. May return a single-subscription or broadcast stream.
inherited
provideOnPushToStreamListeners() → TServiceResolvables<Result<TData>>
Subclasses return per-emission listeners that observe every value pushed via pushToStream (in arrival order). Mixins must call super.provideOnPushToStreamListeners() and prepend/append their own listeners.
inherited
providePauseListeners(void _) → TServiceResolvables<Unit>
Subclasses return the listeners to run when pause is called. Mixins must call super.providePauseListeners(null) and prepend/append their own listeners.
inherited
providePollingInterval() → Duration
Subclasses return the interval between consecutive onPoll invocations. The first poll fires immediately on subscription; subsequent polls fire every providePollingInterval() thereafter.
inherited
provideResumeListeners(void _) → TServiceResolvables<Unit>
Subclasses return the listeners to run when resume is called. Mixins must call super.provideResumeListeners(null) and prepend/append their own listeners.
inherited
pushToStream(Result<TData> data, {bool eagerError = false}) → Resolvable<Option<Object>>
Forwards a data event into the broadcast controller and runs every listener from provideOnPushToStreamListeners in arrival order via the single per-service _pushSequencer (so emissions never interleave with each other's listener chains).
inherited
registerObserver() → Resolvable<Unit>
Adds this service as a global WidgetsBindingObserver. Idempotent — safe to call multiple times within a single lifetime.
inherited
restartStream() → Resolvable<Unit>
Tears down the current stream and immediately starts a fresh one. Increments the internal epoch so in-flight pushes from the old stream are dropped instead of landing in the new controller/completer.
inherited
resume({bool eagerError = false}) → Resolvable<Unit>
Transitions the service into ServiceState.RESUME_SUCCESS by running listeners from provideResumeListeners.
inherited
stopStream() → Resolvable<Unit>
Cancels the current input subscription, closes the broadcast controller, and resolves initialData with an Err (so awaiters don't hang forever). Safe to call repeatedly: subsequent calls become no-ops.
inherited
toString() → String
A string representation of this object.
inherited
unregisterObserver() → Resolvable<Unit>
Removes this service as a global WidgetsBindingObserver. Idempotent — safe to call multiple times.
inherited

Operators

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