How to recover a list?

Question

hello, I’m making a screen where the user can add new words, edit them and delete them and also can search the words they added. However I want the list of words that the user made appears on the screen but this list is only appearing when I type a word a first time and I want this list to appear even if the user has not typed a word.

import 'package:intl/intl.dart';
import 'package:flutter/material.dart';
import 'package:projeto_tcc/helper/VocabularioHelper.dart';
import 'package:projeto_tcc/model/Vocabulario.dart';
import 'package:intl/date_symbol_data_local.dart';

class Tela_Vocabulario_Coreano extends StatefulWidget {
@override
_Tela_Vocabulario_CoreanoState createState() => _Tela_Vocabulario_CoreanoState();
}

class _Tela_Vocabulario_CoreanoState extends State<Tela_Vocabulario_Coreano> {
TextEditingController _palavraController = TextEditingController();
TextEditingController _traducaoController = TextEditingController();
var _db = VocabularioHelper();
List <Vocabulario> _vocabularios = List<Vocabulario>();
List<Vocabulario> retorno = List<Vocabulario>();



 _exibirTelaCadastro( {Vocabulario vocabulario} ){
String textoSalvarAtualizar = "";
if(vocabulario == null){//salvando

  _palavraController.text = "";
  _traducaoController.text = "";
  textoSalvarAtualizar = "Adicionar";
}
else{//atualizando

  _palavraController.text = vocabulario.palavra;
  _traducaoController.text = vocabulario.traducao;
  textoSalvarAtualizar = "Atualizar";

}

 showDialog(
context: context,
builder: (contex){

  return AlertDialog(
    title: Text("$textoSalvarAtualizar Nova Palavra"),
    content: SingleChildScrollView(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: <Widget>[
          TextField(
            controller: _palavraController,
            autofocus: true,
            decoration: InputDecoration(
              labelText: "Palavra",
              hintText: "Digite a palavra",
              border: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(30)
              ),
              ),
              ),
          SizedBox(height: 5,),
          TextField(
            controller: _traducaoController,
            autofocus: true,
            decoration: InputDecoration(
              labelText: "Significado",
              hintText: "Digite a tradução",
              border: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(30)
              ),
            ),
          ),
        ],
      ),
    ),
    actions: <Widget>[
      RaisedButton(
        shape: new RoundedRectangleBorder(borderRadius:
        new BorderRadius.circular(30.0)),
        color: Color(0xffD9D9D9),
        child: Text("Cancelar", style: TextStyle(color: Colors.black),),
        onPressed:()=> Navigator.pop(context),
      ),
      RaisedButton(
        shape: new RoundedRectangleBorder(borderRadius:
        new BorderRadius.circular(30.0)),
        color: Color(0xff5CE6B8),
        child: Text("$textoSalvarAtualizar", style: TextStyle(color: Colors.black),),
        onPressed:(){
          _salvarAtualizarVocabulario(vocabularioSelecionada: vocabulario);
          Navigator.pop(context);
        },
      ),
    ],
  );
    },
    );

    }

_recuperarPalavras() async {

List vocabulariosRecuperadas = await _db.recuperarPalavras();
List <Vocabulario> listaTemporaria = List<Vocabulario>();
for( var item in vocabulariosRecuperadas ){

  Vocabulario vocabulario = Vocabulario.fromMap(item);
  listaTemporaria.add(vocabulario);

}

setState(() {
  _vocabularios = listaTemporaria;
});
listaTemporaria = null;

print("Lista palavras " + vocabulariosRecuperadas.toString());

  }


 _salvarAtualizarVocabulario({Vocabulario vocabularioSelecionada}) async {

String palavra = _palavraController.text;
String traducao = _traducaoController.text;

if(vocabularioSelecionada == null){//salvar

  Vocabulario vocabulario = Vocabulario(palavra, traducao);
  int resultado = await _db.salvarVocabulario(vocabulario);
}

else{//atualizar

  vocabularioSelecionada.palavra = palavra;
  vocabularioSelecionada.traducao = traducao;
  int resultado = await _db.atualizarVocabulario(vocabularioSelecionada);

}

_palavraController.clear();
_traducaoController.clear();
_recuperarPalavras();

}

_removerVocabulario(int id)async{

await _db.removerVocabulario(id);

_recuperarPalavras();

 }



 @override
 void initState() {
// TODO: implement initState
super.initState();
_recuperarPalavras();
retorno = _vocabularios;
}

 @override
 Widget build(BuildContext context) {

_recuperarPalavras();

Size size = MediaQuery.of(context).size;
return Scaffold(
  backgroundColor: Color(0xff5CE6B8),
  appBar: AppBar(
    elevation: 0,
    backgroundColor: Color(0xff5CE6B8),
  ),

  body: SafeArea(
      child: Column(
        children: <Widget>[
          Text(
            "VOCABULÁRIO",
            style: TextStyle(
                fontSize: 20,
                fontWeight: FontWeight.bold
            ),
          ),
          Expanded(
            child: Stack(
              children: <Widget>[
                Container(
                  decoration: BoxDecoration(
                    color: Colors.white,
                    borderRadius: BorderRadius.only(
                        topLeft: Radius.circular(40),
                        topRight: Radius.circular(40)
                    ),

                  ),
                ),
                Container(
                  margin: EdgeInsets.all(20),
                  decoration: BoxDecoration(
                      borderRadius: BorderRadius.circular(30),
                      color: Colors.grey[200]
                  ),
                  child: TextField(
                    decoration: InputDecoration(
                      border: InputBorder.none,
                      contentPadding: EdgeInsets.all(10),
                      hintText: "Digite uma palavra",
                    ),
                    onChanged: (string) {
                      setState(() {
                        retorno = _vocabularios.where((u) => (u.palavra.toLowerCase().contains(string.toLowerCase()) ||
                            u.traducao.toLowerCase().contains(string.toLowerCase()))).toList();
                      });

                    },
                  ),
                ),
                Padding(
                  padding: EdgeInsets.only(top: 60),
                  child: Column(
                    children: <Widget>[
                      Expanded(
                          child: ListView.builder(
                              itemCount: retorno.length,
                              itemBuilder: (context, index){

                                final vocabulario = _vocabularios[index];

                                return Card(
                                  child: ListTile(
                                    title: Text( vocabulario.palavra.toLowerCase() ),
                                    subtitle: Text(vocabulario.traducao.toLowerCase()) ,
                                    trailing: Row(
                                      mainAxisSize: MainAxisSize.min,
                                      children: <Widget>[
                                        GestureDetector(
                                          onTap: (){
                                            _exibirTelaCadastro(vocabulario: vocabulario);
                                          },
                                          child: Padding(
                                              padding: EdgeInsets.only(right: 16),
                                            child: Icon(
                                                Icons.edit,
                                              color: Color(0xff9CE6B9),
                                            ),
                                          ),
                                        ),
                                        GestureDetector(
                                          onTap: (){
                                            return DateFormat.s(showDialog(
                                              context: context,
                                              builder: (contex){

                                                return AlertDialog(
                                                  title: Text("Deletar Palavra"),
                                                  content: Text("Deseja deletar esse item?"),
                                                  actions: <Widget>[
                                                    RaisedButton(
                                                      shape: new RoundedRectangleBorder(borderRadius:
                                                      new BorderRadius.circular(30.0)),
                                                      color: Color(0xffD9D9D9),
                                                      child: Text("Cancelar", style: TextStyle(color: Colors.black),),
                                                      onPressed:()=> Navigator.pop(context),
                                                    ),
                                                    RaisedButton(
                                                      shape: new RoundedRectangleBorder(borderRadius:
                                                      new BorderRadius.circular(30.0)),
                                                      color: Color(0xff5CE6B8),
                                                      child: Text("Deletar", style: TextStyle(color: Colors.black),),
                                                      onPressed:(){
                                                        _removerVocabulario(vocabulario.id);                                                            Navigator.pop(context);
                                                      },
                                                    ),
                                                  ],
                                                );
                                              },
                                            )
                                            );
                                          },
                                          child: Padding(
                                            padding: EdgeInsets.only(right: 0),
                                            child: Icon(
                                              Icons.delete,
                                              color: Colors.grey,
                                            ),
                                          ),
                                        ),
                                      ],
                                    ),
                                  ),
                                );
                              }
                          )
                      )
                    ],
                  ),
                ),



              ],
            ),
          )
        ],
      )
  ),
  floatingActionButton: FloatingActionButton(
      backgroundColor: Color(0xff5CE6B8),
      foregroundColor: Colors.white,
      child: Icon(Icons.add),
      onPressed: (){
        _exibirTelaCadastro();
      }
  ),
);
}
 }