Flutter replace static List with Firebase Query - flutter

Question

can anybody show me how to replace the static list (_dataFromQuerySnapShot) with Firestore Firebase QuerySnapshot? Thank you!
`
import 'dart:async';
import 'package:flutter/material.dart';
class SearchWidget extends StatelessWidget {
const SearchWidget({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return SingleChildScrollView(
child: Column(
children: <Widget>[
const TextField(onChanged: _filter),
StreamBuilder<List<User>>(
stream: _stream,
builder: (context, snapshot) {
return StreamBuilder<List<User>>(
key: ValueKey(snapshot.data),
initialData: snapshot.data,
stream: _stream,
builder: (context, snapshot) {
return ListView.builder(
shrinkWrap: true,
itemCount: snapshot.data?.length,
itemBuilder: (BuildContext context, int index) {
final data = snapshot.data?[index]?.name;
return Text(data!);
},
);
},
);
},
)
],
),
);
}
}
StreamController<List<MyUser>> _streamController = StreamController<List<MyUser>>();
Stream<List<MyUser>> get _stream => _streamController.stream;
_filter(String searchQuery) async {
List<MyUser> _dataFromQuerySnapShot = await getData();
List<MyUser> _filteredList = _dataFromQuerySnapShot.where((MyUser user) => user.firstName!.toLowerCase().contains(searchQuery.toLowerCase())).toList();
_streamController.sink.add(_filteredList);
}
Future<List<MyUser>> getData() async {
List<MyUser> dataList = [];
CollectionReference myRef = FirebaseFirestore.instance.collection('users');
QuerySnapshot querySnapshot = await myRef.get();
dataList.addAll(querySnapshot.docs.map((d) => MyUser.fromJson(d.data() as Map<String, dynamic>)));
return dataList;
}
`
I tried to get data by Future<List> getData() {...} but List _filteredList = getData(); doesn't work as well as a lot of other tries. I only need to see a simple solution of my example working with firebase (StreamController a.s.o.) please. The best solution will include instead of searching in name searching in a String of 'firstName', 'lastName', and 'nickName'...