Best practice to update value from another class - flutter

Question

I am new to flutter, so please excuse my experience.
I have 2 classes, both stateful widgets.
One class contains the tiles for a listview.
Each tile class has a checkbox with a state bool for alternating true or false.
The other class (main) contains the body for creating the listview.
What I'd like to do is retrieve the value for the checkbox in the main class, and then update a counter for how many checkbboxes from the listview tiles have been checked, once a checkbox value is updated. I am wondering what the best practices are for doing this.
Tile class
class ListTile extends StatefulWidget {
#override
_ListTileState createState() => _ListTileState();
}
class _ListTileState extends State<ListTile> {
#override
Widget build(BuildContext context) {
bool selected = false;
return Container(
child: Row(
children: [Checkbox(value: selected, onChanged: (v) {
// Do something here
})],
),
);
}
}
Main Class
class OtherClass extends StatefulWidget {
#override
_OtherClassState createState() => _OtherClassState();
}
class _OtherClassState extends State<OtherClass> {
#override
Widget build(BuildContext context) {
return Container(
child: Column(
children: [
Text("Checkbox selected count <count here>"),
ListView.builder(itemBuilder: (context, index) {
// Do something to get the selected checkbox count from the listview
return ListTile();
}),
],
),
);
}
}

Answer 1

Hope this is you are waiting for
class OtherClass extends StatefulWidget {
#override
_OtherClassState createState() => _OtherClassState();
}
class _OtherClassState extends State<OtherClass> {
bool selected = false;
#override
void initState() {
super.initState();
}
var items = [
Animal("1", "Buffalo", false),
Animal("2", "Cow", false),
];
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text("title")),
body: Container(
child: ListView.builder(
itemCount: items.length,
shrinkWrap: true,
itemBuilder: (ctx, i) {
return Row(
children: [
Text(items[i].name),
ListTile(
id: items[i].id,
index: i,
)
],
);
}),
));
}
}
ListTileClass
class ListTile extends StatefulWidget {
final String? id;
final int? index;
final bool? isSelected;
const ListTile ({Key? key, this.id, this.index, this.isSelected})
: super(key: key);
#override
_ListTileState createState() => _ListTileState();
}
class _ListTileState extends State<ListTile> {
bool? selected = false;
#override
void initState() {
super.initState();
}
#override
Widget build(BuildContext context) {
return Container(
width: 20,
child: Checkbox(
value: selected,
onChanged: (bool? value) {
setState(() {
selected = value;
});
}));
}
}

Answer 2

I'd recommend using a design pattern such as BLoC or using the Provider package. I personally use the Provider Package. There are plenty of tutorials on youtube which can help get you started.