Login Screen Flutter

import 'package:bic/data/PreferencesManager.dart';
import 'package:bic/data/tachos_database.dart';
import 'package:bic/home/home_page.dart';
import 'package:bic/login/login_bloc.dart';
import 'package:bic/login/login_event.dart';
import 'package:bic/login/login_state.dart';
import 'package:bic/res/colors.dart';
import 'package:bic/res/strings.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:package_info/package_info.dart';
import 'package:progress_dialog/progress_dialog.dart';

class LoginForm extends StatefulWidget {
  final LoginBloc loginBloc;

  LoginForm({Key key, @required this.loginBloc}) : super(key: key);

  @override
  State<LoginForm> createState() => _LoginFormState();
}

class _LoginFormState extends State<LoginForm> {
  final focus = FocusNode();
  bool _obscurePassword = true;
  final _loginTextContoller = TextEditingController();
  final _passwordTextController = TextEditingController();

  LoginBloc get _loginBloc => widget.loginBloc;

  ProgressDialog _progressDialog;
  String version = "";
  String buildNumber = "";

  @override
  void initState() {
    super.initState();
    String username = PreferencesManager.getPrefWithDefault(PreferencesManager.USER, "");
    String pass = PreferencesManager.getPrefWithDefault(PreferencesManager.PASS, "");
    print('Username - $username , Password - $pass');
    _loginTextContoller.text = username;
    _passwordTextController.text = pass;

    PackageInfo.fromPlatform().then((PackageInfo packageInfo) {
      String appName = packageInfo.appName;
      String packageName = packageInfo.packageName;
      version = packageInfo.version;
      buildNumber = packageInfo.buildNumber;
      setState(() {});
    });
  }

  @override
  Widget build(BuildContext context) {
    return BlocListener(
      bloc: _loginBloc,
      listener: (context, state) {
        print("LoginBlocListener " + state.toString());
        //hide progress bar in anycase
        if (_progressDialog != null && _progressDialog.isShowing()) _progressDialog.hide();

        if (state is LoginLoading) {
          if (_progressDialog == null) _progressDialog = new ProgressDialog(context, ProgressDialogType.Normal);

          if (!_progressDialog.isShowing()) {
            _progressDialog.setMessage(ProjectStrings.LOADING);
            _progressDialog.show();
          }
        }

        if (state is LoginFailure) {
          Scaffold.of(context).showSnackBar(
            SnackBar(
              content: Text('${state.error}'),
              backgroundColor: Colors.red,
            ),
          );
        }

        if (state is LoginFinish) {
          goToNextScreen();
        }

//        Scaffold.of(context).showSnackBar(
//          SnackBar(
//            content: Text(state.toString()),
//            backgroundColor: Colors.red,
//          ),
//        );
      },
      child: BlocBuilder<LoginEvent, LoginState>(
        bloc: _loginBloc,
        condition: (previousState, currentState) {
          if (currentState is LoginLoading || currentState is LoginFailure || currentState is LoginFinish) return false;
          return true;
        },
        builder: (context, state) {
          print("LoingBlocBuilder " + state.toString());
          return Form(
            child: SingleChildScrollView(
              child: Container(
                height: double.maxFinite,
                decoration: new BoxDecoration(color: ProjectColors.COLOR_BACKGROUND),
                child: Column(
                  children: [
                    Padding(
                      padding: const EdgeInsets.only(top: 60.0),
                    ),
                    Image.asset(
                      "data_repo/icon.png",
                      width: 160,
                      height: 160,
                      fit: BoxFit.cover,
                    ),
                    Text(
                      "Version No : ${version}+${buildNumber}",
                      style: TextStyle(color: Colors.green, fontSize: 18),
                    ),
                    Padding(
                      padding: const EdgeInsets.only(top: 40.0),
//                          child: Image(
//                              width: 160,
//                              height: 160,
//                              image: AssetImage(ProjectImages.BIC_LOGO),
//                              fit: BoxFit.contain)
                    ),
                    Padding(
                      padding: EdgeInsetsDirectional.only(start: 50.0, end: 50.0),
                      child: TextFormField(
                        keyboardType: TextInputType.emailAddress,
                        textInputAction: TextInputAction.next,
                        onFieldSubmitted: (v) {
                          FocusScope.of(context).requestFocus(focus);
                        },
                        controller: _loginTextContoller,
                        decoration: new InputDecoration(
                          hintText: ProjectStrings.MAIL,
                        ),
                      ),
                    ),
                    Container(
                      padding: EdgeInsetsDirectional.only(start: 50.0, end: 50.0),
                      child: Row(
                        mainAxisAlignment: MainAxisAlignment.end,
                        crossAxisAlignment: CrossAxisAlignment.center,
                        children: [
                          Flexible(
                            child: TextFormField(
                              focusNode: focus,
                              onFieldSubmitted: (v) {
                                FocusScope.of(context).unfocus();
                              },
                              controller: _passwordTextController,
                              decoration: new InputDecoration(hintText: ProjectStrings.PASSWORD),
                              obscureText: _obscurePassword,
                            ),
                          ),
                          IconButton(
                              icon: _obscurePassword
                                  ? Icon(Icons.remove_red_eye, color: Colors.grey)
                                  : Icon(Icons.remove_red_eye, color: Colors.blue),
                              onPressed: _toggle)
                        ],
                      ),
                    ),
                    Padding(
                      padding: EdgeInsetsDirectional.only(top: 50.0),
                      child: MaterialButton(
                        minWidth: 200,
                        color: ProjectColors.COLOR_ACCENT,
                        child: Text(
                          ProjectStrings.AUTH,
                          style: TextStyle(fontSize: 16.0, color: Colors.white),
                        ),
                        onPressed: _onLoginButtonPressed,
                      ),
                    ),
                  ],
                ),
              ),
            ),
          );
        },
      ),
    );
  }

  void _toggle() {
    setState(() {
      _obscurePassword = !_obscurePassword;
    });
  }

  void goToNextScreen() {
    Navigator.pushReplacement(
      context,
      MaterialPageRoute(builder: (context) {
        return HomePage();
      }),
    );
  }

  _onLoginButtonPressed() {
    //on login clean the db first and create it again.
    
    SystemChannels.textInput.invokeMethod('TextInput.hide').then((_) {
          _loginBloc.dispatch(
            LoginButtonPressed(
              username: _loginTextContoller.text,
              password: _passwordTextController.text,
            ),
          );
        });
    // TachosDatabase.get().refresh(null).then((_) {
    //   TachosDatabase.get().init().then((_) {
        
    //   });
    // });
  }
}