WidgetsBindingObserver class Null safety
Interface for classes that register with the Widgets layer binding.
When used as a mixin, provides no-op method implementations.
See WidgetsBinding.addObserver and WidgetsBinding.removeObserver.
This class can be extended directly, to get default behaviors for all of the
handlers, or can used with the implements keyword, in which case all the
handlers must be implemented (and the analyzer will list those that have
been omitted).
This sample shows how to implement parts of the State and
WidgetsBindingObserver protocols necessary to react to application
lifecycle messages. See didChangeAppLifecycleState.
To create a local project with this code sample, run:
flutter create --sample=widgets.WidgetsBindingObserver.1 mysample
flutter create --sample=widgets.WidgetsBindingObserver.1 mysample
To respond to other notifications, replace the didChangeAppLifecycleState method above with other methods from this class.
Constructors
Properties
- hashCode → int
-
The hash code for this object.
read-onlyinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
read-onlyinherited
Methods
-
didChangeAccessibilityFeatures(
) → void - Called when the system changes the set of currently active accessibility features.
-
didChangeAppLifecycleState(
AppLifecycleState state) → void - Called when the system puts the app in the background or returns the app to the foreground.
-
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.
-
didChangeMetrics(
) → void - Called when the application's dimensions change. For example, when a phone is rotated.
-
didChangePlatformBrightness(
) → void - Called when the platform brightness changes.
-
didChangeTextScaleFactor(
) → void - Called when the platform's text scale factor changes.
-
didHaveMemoryPressure(
) → void - Called when the system is running low on memory.
-
didPopRoute(
) → Future< bool> - Called when the system tells the app to pop the current route. For example, on Android, this is called when the user presses the back button.
-
didPushRoute(
String route) → Future< bool> - Called when the host tells the application to push a new route onto the navigator.
-
didPushRouteInformation(
RouteInformation routeInformation) → Future< bool> - Called when the host tells the application to push a new RouteInformation and a restoration state onto the router.
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed.
inherited
-
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited