Google Authentication with Flutter

dependencies: flutter: sdk: flutter google_sign_in: ^4.0.2 

import 'package:flutter/material.dart'; import 'package:google_sign_in/google_sign_in.dart'; void main() => runApp(MyApp()); class MyApp extends StatefulWidget { @override State<StatefulWidget> createState() { // TODO: implement createState return _MyAppState(); } } class _MyAppState extends State<MyApp> { bool _isLoggedIn = false; GoogleSignIn _googleSignIn = GoogleSignIn(scopes: ['email']); _login() async{ try{ await _googleSignIn.signIn(); setState(() { _isLoggedIn = true; }); } catch (err){ print(err); } } _logout(){ _googleSignIn.signOut(); setState(() { _isLoggedIn = false; }); } @override Widget build(BuildContext context) { // TODO: implement build return MaterialApp( home: Scaffold( body: Center( child: _isLoggedIn ? Column( mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[ Image.network(_googleSignIn.currentUser.photoUrl, height: 50.0, width: 50.0,), Text(_googleSignIn.currentUser.displayName), OutlineButton( child: Text("Logout"), onPressed: (){ _logout(); },) ], ) : Center( child: OutlineButton( child: Text("Login with Google"), onPressed: () { _login(); }, ), )), ), ); } }