import 'package:flutter/material.dart';


class CredentialsForm extends StatefulWidget {
  CredentialsForm({Key key}) : super(key: key);

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

class _CredentialsState extends State<CredentialsForm> {
  String username;
  String password;
  bool _hidden = true;
  final _credFormKey = GlobalKey<FormState>();
  InputDecoration _textFieldDecoration(String label, IconData icon) {
    return InputDecoration(
      labelText: label,
      icon: Icon(icon),
      hintText: 'Please, insert your zucchetti account $label',
    );
  }

  String validateUsername(String username) {
    if (username.isEmpty) {
      return 'Username must not be empty';
    }
    return null;
  }

  String validatePassword(String password) {
    if (password.isEmpty) {
      return 'Password must not be empty';
    }
    return null;
  }

  @override
  Widget build(BuildContext context) {
    return Form(
        key: _credFormKey,
        child: Column(children: <Widget>[
          TextFormField(
              autofocus: true,
              autocorrect: false,
              decoration:
                  this._textFieldDecoration("username", Icons.alternate_email),
              validator: this.validateUsername),
          TextFormField(
              autocorrect: false,
              decoration: this._textFieldDecoration("password", Icons.lock),
              validator: this.validatePassword,
              obscureText: this._hidden),
          Row(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: <Widget>[
            RaisedButton(
              onPressed: () {
                if (_credFormKey.currentState.validate()) {
                  Scaffold.of(context)
                      .showSnackBar(SnackBar(content: Text('Processing Data')));
                }
              },
              child: Text('Validate'),
            ),
            Row(children: <Widget>[
              Text('Reveal password'),
              Checkbox(
                  value: !this._hidden,
                  onChanged: (bool value) {
                    setState(() {
                      _hidden = !value;
                    });
                    return;
                  })
            ])
          ]),
        ]));
  }
}