LogIn screen skipped on flutter - user-interface

Question

Currently I am designing my UI for the login screen and Firebase authentication is already in effect as I can see the username on the firebase console, however I try to edit my UI for the login screen, but the login screen is skipped and is continuously logged in, so I cannot see the changes I am making for the UI of my login screen, here is my code:
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';
import 'package:fluttertoast/fluttertoast.dart';
import 'package:google_sign_in/google_sign_in.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'home.dart';
class Login extends StatefulWidget {
#override
_LoginState createState() => _LoginState();
}
class _LoginState extends State<Login> {
final GoogleSignIn googleSignIn = new GoogleSignIn();
final FirebaseAuth firebaseAuth = FirebaseAuth.instance;
SharedPreferences preferences;
bool loading = false;
bool isLogedin = false;
#override
void initState() {
super.initState();
isSignedIn();
}
void isSignedIn() async {
setState(() {
loading = true;
});
preferences = await SharedPreferences.getInstance();
isLogedin = await googleSignIn.isSignedIn();
if (isLogedin) {
Navigator.pushReplacement(
context, MaterialPageRoute(builder: (context) => HomePage()));
}
setState(() {
loading = false;
});
}
Future handleSignIn() async {
preferences = await SharedPreferences.getInstance();
setState(() {
loading = true;
});
GoogleSignInAccount googleUser = await googleSignIn.signIn();
GoogleSignInAuthentication googleSignInAuthentication =
await googleUser.authentication;
AuthCredential credential = GoogleAuthProvider.getCredential(
idToken: googleSignInAuthentication.idToken,
accessToken: googleSignInAuthentication.accessToken);
FirebaseUser firebaseUser =
(await firebaseAuth.signInWithCredential(credential)).user;
if (firebaseUser != null) {
final QuerySnapshot result = await Firestore.instance
.collection("users")
.where("id", isEqualTo: firebaseUser.uid)
.getDocuments();
final List<DocumentSnapshot> documents = result.documents;
if (documents.length == 0) {
//insert the user to our collection
Firestore.instance
.collection("users")
.document(firebaseUser.uid)
.setData({
"id": firebaseUser.uid,
"username": firebaseUser.displayName,
"profilePicture": firebaseUser.photoUrl
});
await preferences.setString("id", firebaseUser.uid);
await preferences.setString("username", firebaseUser.displayName);
await preferences.setString("photUrl", firebaseUser.displayName);
} else {
await preferences.setString("id", documents[0]['id']);
await preferences.setString("username", documents[0]['username']);
await preferences.setString("photoUrl", documents[0]['photoUrl']);
}
Fluttertoast.showToast(msg: "Login was successful");
setState(() {
loading = false;
});
Navigator.pushReplacement(
context, MaterialPageRoute(builder: (context) => HomePage()));
} else {
Fluttertoast.showToast(msg: "Login failed :(");
}
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.white,
centerTitle: true,
title: new Text(
"Login",
style: TextStyle(color: Colors.red.shade900),
),
elevation: 0.1,
),
body: Stack(children: <Widget>[
Visibility(
visible: loading ?? true,
child: Center(
child: Container(
alignment: Alignment.center,
color: Colors.white.withOpacity(0.9),
child: CircularProgressIndicator(
valueColor: AlwaysStoppedAnimation<Color>(Colors.red),
))))
,
]),
bottomNavigationBar: Container(
child: Padding(
padding: const EdgeInsets.only(left:12.0, right: 12, top: 12, bottom: 12),
child: FlatButton(
color: Colors.red.shade900,
onPressed: () {
handleSignIn();
},
child: Text(
'Sign in/ Sign up with Google',
style: TextStyle(color: Colors.white),
)),
),
),
);
}
}
This is my code for the UI of login, however I cannot see the edits I am making on this on my emulator, as the login screen just skips (actually it appears for like 0.5 seconds and goes directly to the homepage). Could someone help me out?

Answer 1

You are navigating the logged-in user to the home page.
void isSignedIn() async {
setState(() {
loading = true;
});
preferences = await SharedPreferences.getInstance();
isLogedin = await googleSignIn.isSignedIn();
if (isLogedin) {
Navigator.pushReplacement(
context, MaterialPageRoute(builder: (context) => HomePage()));
}
setState(() {
loading = false;
});
}
Either you can implement Logout in the app or just comment out the auto logged in part until your testing finish.