handleAppLifecycleStateChanged method
Called when the application lifecycle state changes.
Notifies all the observers using WidgetsBindingObserver.didChangeAppLifecycleState.
This method exposes notifications from SystemChannels.lifecycle.
Implementation
@override
void handleAppLifecycleStateChanged(AppLifecycleState state) {
super.handleAppLifecycleStateChanged(state);
for (ElementsBindingObserver observer in _observers) observer.didChangeAppLifecycleState(state);
}