flutter dynamic navigation bar: identify which icon/button is tapped - flutter

Question

I am creating a dynamic list of BottomNavigationBarItem and assigning it to 'items' of BottomNavigationBar. So based on a condition (here is my case, checks and add one more BottomNavigationBarItem if it is not billed. So the number of Icons displayed change.
Normally for a fixed number of items, ontap provide index of the icon tapped. As the order/sequence of icons change, their index also differs.
Now how do I read the label of selected BottomNavigationBarItem and respond in onTap handler instead of tapped index value ?
(Of course in this particular case, I can add the additional button as last one and done with. Need a better solution.)
List<BottomNavigationBarItem> getNavbarItems() {
List<BottomNavigationBarItem> navItems = [];
navItems.add(
const BottomNavigationBarItem(
icon: Icon(Icons.delete_outline,), label: 'Delete',),
);
if (widget.invStatus.isBilled == 0) {
navItems.add(
const BottomNavigationBarItem(
icon: Icon(Icons.receipt), label: 'Bill it ?'),
);
}
navItems.add(
const BottomNavigationBarItem(
icon: Icon(Icons.category_rounded), label: 'Add a Product !'),
);
return navItems;
}
Thanks.

Answer 1

If I understand you correctly, you can use the following approach to get the "label".
Call:
getNavbarItems()[index].label
And have a button to dynamically toggle isBilled.
Complete example:
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: Center(
child: Nav(),
),
),
);
}
}
class Nav extends StatefulWidget {
#override
createState() => NavState();
}
class NavState extends State<Nav> {
var _selectedIndex = 0;
var billIt = false;
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Nav'),
),
body: Center(
child: TextButton(
child: Text('Toggle `billIt`'),
onPressed: () {
setState(() {
billIt = !billIt;
});
},
),
),
bottomNavigationBar: BottomNavigationBar(
currentIndex: _selectedIndex,
items: getNavbarItems(),
onTap: (int index) {
setState(() {
_selectedIndex = index;
print('label: ${getNavbarItems()[index].label}');
});
},
),
);
}
List<BottomNavigationBarItem> getNavbarItems() {
List<BottomNavigationBarItem> navItems = [];
navItems.add(
const BottomNavigationBarItem(
icon: Icon(
Icons.delete_outline,
),
label: 'Delete',
),
);
if (billIt) {
navItems.add(
const BottomNavigationBarItem(
icon: Icon(Icons.receipt), label: 'Bill it ?'),
);
}
navItems.add(
const BottomNavigationBarItem(
icon: Icon(Icons.category_rounded), label: 'Add a Product !'),
);
return navItems;
}
}