[GREEN] added code for typeahead latar belakang

lib/pages/kyc/biodata_pendukung.dart

 import 'package:flutter/material.dart';
+import 'package:flutter_typeahead/flutter_typeahead.dart';
 import 'package:fundex_app/assets/colors.dart';
 import 'package:fundex_app/main-screen.dart';
 import 'package:fundex_app/pages/kyc/data_identitas.dart';
@@ -23,6 +24,12 @@ class ValidasiEmail {
   }
 }
 
+class ValidasiTempat{
+  static String validate(String value){
+    return value.isEmpty ? 'Harus di isi.' : null;
+  }
+}
+
 class DataPendukung extends StatefulWidget {
   @override
   _DataPendukungState createState() => _DataPendukungState();
@@ -30,6 +37,7 @@ class DataPendukung extends StatefulWidget {
 
 class _DataPendukungState extends State<DataPendukung> {
   final GlobalKey<FormState> _formkey = GlobalKey<FormState>();
+  final TextEditingController _typeAheadController = TextEditingController();
 
   // ignore: unused_field
   String _latarBelakang;
@@ -52,6 +60,7 @@ class _DataPendukungState extends State<DataPendukung> {
   bool valueCheckbox = false;
   bool _checkBox = false;
   var _onPressed;
+  String dropdownValue;
 
   final notifikasiCheckbox = [
     CheckboxNotificationSetting(title: 'Gaji'),
@@ -99,6 +108,20 @@ class _DataPendukungState extends State<DataPendukung> {
       _onPressed = null;
     }
 
+    List<String> listLatarBelakang(String query) {
+      List<String> matches = [];
+      matches.add("SD");
+      matches.add("SMP");
+      matches.add("SMA");
+      matches.add("D3");
+      matches.add("D4");
+      matches.add("S1");
+      matches.add("S2");
+      matches.add("S3");
+      matches.add("Lainnya");
+      matches.retainWhere((s) =>   s.toLowerCase().contains(query.toLowerCase()));
+      return matches;
+    }
 
     return MaterialApp(
         home: Scaffold(
@@ -243,6 +266,34 @@ class _DataPendukungState extends State<DataPendukung> {
                                           style: miniTitleTextStyle(),
                                         ),
                                       ),
+                                      
+                                      Container(
+                                        width: 343,
+                                        child: TypeAheadFormField(
+                                          key: Key('latarBelakangPend'),
+                                          textFieldConfiguration: TextFieldConfiguration(
+                                          controller: this._typeAheadController,
+                                          decoration: formInputDecoration()
+                                          ),
+                                          suggestionsCallback: (pattern) {
+                                            return listLatarBelakang(pattern);
+                                          },
+                                          itemBuilder: (context, suggestion) {
+                                            return ListTile(
+                                              title: Text(suggestion),
+                                            );
+                                          },
+                                          transitionBuilder: (context, suggestionsBox, controller) {
+                                            return suggestionsBox;
+                                          },
+                                          onSuggestionSelected: (suggestion) {
+                                            this._typeAheadController.text = suggestion;
+                                          },
+                                          // ignore: missing_return
+                                          validator: ValidasiTempat.validate,
+                                          onSaved: (value) => this._latarBelakang = value,
+                                          ),
+                                      ),
                                     ])
                                   ],
                                 ),