show warning worker name empty

lib/presentation/screens/actions/nursery/sc_edit_action_nursery.dart

   int selectedSupplyId = -1;
   List<String> filePaths = List<String>();
   var changeFileController = Get.put(ChangeFileController());
-  GlobalKey<FormState> _formWorkerKey = GlobalKey();
 
   Future<Null> getSharedPrefs() async {
     var currentFullName = await pref.getString(DATA_CONST.CURRENT_FULL_NAME);
                 color: Colors.white,
                 border: Border.all(color: COLOR_CONST.DEFAULT)),
             child: Form(
-              key: _formWorkerKey,
               child: Column(
                 children: [
                   TextFormField(
                             shape: RoundedRectangleBorder(
                                 borderRadius: new BorderRadius.circular(8.0)),
                             onPressed: () {
-                              if (_formWorkerKey.currentState.validate()) {
-                                _formWorkerKey.currentState.save();
+                              if (Validators.stringNotNullOrEmpty(
+                                  _workerNameController.text)) {
                                 NurseryDetail _nurseryDetail = NurseryDetail()
                                   ..workerName = _workerNameController.text
                                   ..trayNumber = _trayNumberController.text;
                                 }
                                 context.bloc<StatusAddFormBloc>().add(Reset());
                               } else {
-                                //
+                                Utils.showSnackBarWarning(
+                                    message: "Vui lòng nhập tên công nhân");
                               }
                             },
                             child: Text(