simple_filter_listview

import 'package:flutter/material.dart';
import 'dart:convert';
import 'package:http/http.dart' as http;


const Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: EmpData(),
    );
  }
}



class EmpData extends StatefulWidget {

  @override
  _EmpDataState createState() => _EmpDataState();
}

class _EmpDataState extends State<EmpData> {
  int currentPage = 1;
  List empList = [];
  List filteredList = [];
  //ConfigFile confObj = new ConfigFile();

  //todo: get the data in a list of Strings
  Future<List> getEmpData() async {
   
     // faking making an HTTP call (since I don't have access to your backend)
    return Future.delayed(const Duration(seconds: 2), () {
       
      return [
        {'emp_code': '12212',
         'first_name': 'Roman',
         'last_name': 'Jaquez',
         'photo': 'photo_url'
        },
        {'emp_code': '12213',
         'first_name': 'Salim',
         'last_name': 'Dziri',
         'photo': 'photo_url'
        },
         {'emp_code': '12214',
         'first_name': 'John',
         'last_name': 'Doe',
         'photo': 'photo_url'
        },
         {'emp_code': '12215',
         'first_name': 'Jane',
         'last_name': 'Smith',
         'photo': 'photo_url'
        }
      ];
    });
  }

final TextEditingController editingController = TextEditingController();
  
ValueNotifier<String> empName = ValueNotifier('');

void changed(String query) {

  filteredList = empList.where((e) => e['first_name'].toString().toLowerCase() == query.toLowerCase()).toList();
  empName.value = query;
}
  


@override
Widget build(BuildContext context) {
  return Scaffold(
      appBar: AppBar(
        title: Text("Employees List"),
        centerTitle: true,
    ),
    body: Column(
      children: <Widget>[
        //todo: chearch field
        SizedBox(height: 20),
        TextField(
          controller: editingController,
          onChanged: changed,
          decoration: InputDecoration(
              labelText: "Search",
              hintText: "Search",
              prefixIcon: Icon(Icons.search),
              border: OutlineInputBorder(
                  borderRadius: BorderRadius.all(Radius.circular(25.0)))),
        ),
        
        FutureBuilder<List>(
            future: getEmpData(),
            builder: (ctx,ss){
              if(ss.hasData){
                empList = ss.data!;
                return Expanded(
                  child: ValueListenableBuilder<String>(
                    valueListenable: empName,
                    builder: (context, value, child) {

                    var listViewList = value.isEmpty ? empList : filteredList;
                      
                      return ListView.builder(
                    itemCount: listViewList.length,
                    itemBuilder: (ctx,i){
                      return ListTile(
                        onTap: (){
                          // do whatever you want here
                        },

                        subtitle: Text("id: #${listViewList[i]['emp_code']}"),
                        title: Text("${listViewList[i]['first_name']}  ${listViewList[i]['last_name']}"),
                      );
                    });
                }));
                
              }else{
                return Center(child: CircularProgressIndicator());
              }
            }
        )

      ],
    )
);

}
}

hello, thank you for your help, i got a problem that whenever i type anything in the search bar i got an empty list and when i delete everything the previous list return normal, so i tried to print(listViewList) and it became empty after i search anything here's what i get without searching anything :

i also want to search with full name (first_name + last_name) as well as emp_code