import 'package:flutter/material.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Contacts',
      theme: new ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: new MyHomePage(title: 'Contacts App Flutter'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {

  User _newUser = User();
  List<User> _contacts = [];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title)
      ),
      body: Column(
        children: <Widget>[
          Form(
            child: Column(
              children: <Widget>[
                TextFormField(
                  decoration: InputDecoration(
                    hintText: 'Nome do contato',
                    labelText: 'Nome'
                  ),
                  onSaved: (value) => setState(() => _newUser.name = value),
                ),
                TextFormField(
                  keyboardType: TextInputType.numberWithOptions(),
                  decoration: InputDecoration(
                    hintText: '000000000',
                    labelText: 'Número'
                  ),
                  onSaved: (value) => setState(() => _newUser.number = value as int),
                ),
                RaisedButton(
                    child: Text('Add'),
                    onPressed: () => submit()
                )
              ],
            ),
          ),
          Flexible(child: _buildList())
        ],
      )
    );
  }

  submit() {
     setState(() => _contacts.add(_newUser));
  }

  _buildList() {
    return ListView.builder(itemBuilder: (context, index){
      if (index < _contacts.length) {
        return ListTile(
          title: Text(_contacts[index].name),
          subtitle: Text(_contacts[index].number as String),
        );
      } //EndIf
    }
    );
  }
}

class User {
  String name;
  int number;

}