onInit method
Called immediately after the widget is allocated in memory. You might use this to initialize something for the controller.
Implementation
@override
void onInit() {
WidgetsBinding.instance.addObserver(this);
SystemChrome.setPreferredOrientations(
[DeviceOrientation.landscapeLeft, DeviceOrientation.landscapeRight]);
SystemChrome.setEnabledSystemUIMode(SystemUiMode.immersiveSticky,
overlays: [SystemUiOverlay.bottom]);
super.onInit();
}