Flutter onPressed trigger State of another widget - flutter

Question

I need help with flutter build management. My Goal is to rebuild my side navigation bar with the SmallSideMenu() or the opposite SideMenu().
Do you have an idea how I can trigger the Build process of my LargeView widget, so that it's rebuilt with the correspondent SideMenu?
The button is defined like this:
IconButton(
onPressed: () {
checkState();
},
icon: HeroIcon(
HeroIcons.arrowNarrowRight,
size: 16.0,
),
),
The value of the sideMenuOpen variable and function is set globally;
checkState() {
if (sideMenuOpen == true) {
sideMenuOpen = false;
} else {
sideMenuOpen = true;
}
}
the SideMenu is defined here.
class LargeView extends StatefulWidget {
const LargeView({
Key? key,
}) : super(key: key);
#override
State<LargeView> createState() => _LargeViewState();
}
class _LargeViewState extends State<LargeView> {
#override
Widget build(BuildContext context) {
return Row(
children: [
Expanded(
child: SizedBox(
width: 100,
child: sideMenuOpen ? SideMenu() : SmallSideMenu(),
),
),
Expanded(
flex: 10,
child: Container(
width: double.infinity,
padding: const EdgeInsets.all(20.0),
color: greyColor,
child: Expanded(
child: Container(
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(15.0)),
child: localNavigator())),
),
)
],
);
}
}

Answer 1

make sideMenuOpen a state in stateful widget and use setState as
checkState() {
if (sideMenuOpen == true) {
setState((){
sideMenuOpen = false;
});
} else {
setState((){
sideMenuOpen = true;
});
}
}
if you want to keep state (open/close) of navigation bar globally for that use some state management like provider instead of using global function.

Answer 2

You can use ValueNotifier instead of single bool. And to update UI it can be used on ValueListenableBuilder.
final ValueNotifier<bool> sideMenuOpen = ValueNotifier(false);
And
child: SizedBox(
width: 100,
child: ValueListenableBuilder<bool>(
valueListenable: sideMenuOpen,
builder: (context, value, child) => value
? SideMenu(),
: SmallSideMenu(),
),
),
And change value like
sideMenuOpen.value = true;