error in implementing search feature in Listview builder - flutter

Question

I'm trying to implement search functionality in the list view builder But I don't have an idea to implement it.
this is model class
class Contacts {
String? id;
String? name;
String? display_name;
Contacts({this.id, this.name, this.display_name});
factory Contacts.fromJson(Map<String?, dynamic> json) {
return Contacts(
id: json['id'], name: json['name'], display_name: json['display_name']);
}
Map toJson() => {'id': id, 'name': name, "display_name": display_name};
}
this is the future class
late Future<List<Contacts>> c;
void onInit() async {
c = getContacts();
}
Future<List<Contacts>> getContacts() async {
print("<<<<<GETTING CONTACTS>>>>>>");
// SERVER API URL
Uri url = Uri.parse('http://localhost:8000/get-contacts');
// Store all data with Param Name.
var data = {'sender': id};
//json encode
String? body = json.encode(data);
// Starting Web API Call.
var response = await http.post(url,
headers: <String, String>{
'Content-Type': 'application/json; charset=UTF-8',
},
body: body);
// If Web call Success than Hide the CircularProgressIndicator.
if (response.statusCode == 200) {
final datas = json.decode(response.body).cast<Map<String, dynamic>>();
contacts = datas.map<Contacts>((json) {
return Contacts.fromJson(json);
}).toList();
print(contacts);
return contacts;
} else {
return contacts = [];
}
}
this is view class
FutureBuilder<List<Contacts>>(
future: controller.c,
builder: (context, snapshot) {
if (!snapshot.hasData) {
return Center(
child: CircularProgressIndicator(),
);
} else {
return ListView.builder(
itemCount: snapshot.data?.length,
itemBuilder: (context, index) {
return Card(
child: CheckboxListTile(
title: Text(
snapshot.data![index].name ?? "name"),
value: controller.isChecked[index],
onChanged: (val) {
setState(
() {
print(snapshot.data![index]);
controller.selectContact(
index, val, snapshot.data![index]);
},
);
},
),
);
},
);
}
}),
anyone, please help me to filter the records from the snapshot data.
I successfully implemented it in listview but not in listviewBuildr