MemoryCachePressureWatcher<K, V> class final

Listens to OS memory pressure signals and evicts MemoryCache entries.

Uses Flutter's WidgetsBindingObserver — no custom platform channel needed. Flutter wires didHaveMemoryPressure to:

  • iOS: UIApplicationDidReceiveMemoryWarningNotification
  • Android: onTrimMemory (all trim levels coalesced into one signal)

Usage

final watcher = MemoryCachePressureWatcher(cache: myCache)..attach();

// When your widget/service is disposed:
watcher.detach();

Attaching multiple caches

Create one watcher per cache, or extend this class to evict a list of caches.

Mixed-in types

Constructors

MemoryCachePressureWatcher({required MemoryCache<K, V> cache, MemoryPressureConfig config = const MemoryPressureConfig()})

Properties

cache → MemoryCache<K, V>
The cache to evict entries from under memory pressure.
final
config → MemoryPressureConfig
Eviction fractions and backgrounding behaviour.
final
hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

attach() → void
Registers this watcher with the Flutter WidgetsBinding. Call this once, typically in initState or a service constructor.
detach() → void
Unregisters this watcher. Call in dispose to prevent memory leaks.
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.
override
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.
override
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
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
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
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

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