Can someone help me with my code?

Im doing a socialmedia app right now and i have an issue.
Its like instagram and everything works but not the timeline, where the posts of the persons you are following is shown. I should be working but it doesnt. Maybe someone can help me with my problem…
The code for the timelinepage :

import ‘package:buddiesgram/models/user.dart’;
import ‘package:buddiesgram/pages/HomePage.dart’;
import ‘package:buddiesgram/widgets/HeaderWidget.dart’;
import ‘package:buddiesgram/widgets/PostWidget.dart’;
import ‘package:buddiesgram/widgets/ProgressWidget.dart’;
import ‘package:cloud_firestore/cloud_firestore.dart’;
import ‘package:flutter/material.dart’;
import ‘package:geolocator/geolocator.dart’;

class TimeLinePage extends StatefulWidget
{
final User gCurrentUser;

TimeLinePage({this.gCurrentUser});

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

class _TimeLinePageState extends State
{
List posts;
List followingsList = ;
final _scaffoldKey = GlobalKey();

retrieveTimeLine() async
{
QuerySnapshot querySnapshot = await timelineReference.document(widget.gCurrentUser.id)
.collection(“timelinePosts”).orderBy(“timestamp”, descending: true).getDocuments();

List<Post> allPosts = querySnapshot.documents.map((document) => Post.fromDocument(document)).toList();

setState(() {
  this.posts = allPosts;
});

}

retrieveFollowings() async
{
QuerySnapshot querySnapshot = await followingReference.document(currentUser.id).collection(“userFollowers”).getDocuments();

setState(() {
  followingsList = querySnapshot.documents.map((document) => document.documentID).toList();
});

}

@override
void initState() {
// TODO: implement initState
super.initState();

retrieveTimeLine();
retrieveFollowings();

}

createUserTimeLine()
{
if(posts == null)
{
return circularProgress();
}
else
{
return ListView(children: posts,);
}
}

@override
Widget build(context) {
return Scaffold(
key: _scaffoldKey,

  appBar: header(context, isAppTitle: true, ),

  body: RefreshIndicator(child: createUserTimeLine(), onRefresh: () => retrieveTimeLine()),
);

}
}

The code for the home(main)page:

import ‘dart:io’;
import ‘package:buddiesgram/models/user.dart’;
import ‘package:buddiesgram/pages/CreateAccountPage.dart’;
import ‘package:buddiesgram/pages/NotificationsPage.dart’;
import ‘package:buddiesgram/pages/ProfilePage.dart’;
import ‘package:buddiesgram/pages/SearchPage.dart’;
import ‘package:buddiesgram/pages/TimeLinePage.dart’;
import ‘package:buddiesgram/pages/UploadPage.dart’;
import ‘package:cloud_firestore/cloud_firestore.dart’;
import ‘package:firebase_messaging/firebase_messaging.dart’;
import ‘package:firebase_storage/firebase_storage.dart’;
import ‘package:flutter/cupertino.dart’;
import ‘package:flutter/material.dart’;
import ‘package:google_sign_in/google_sign_in.dart’;

final GoogleSignIn gSignIn = GoogleSignIn();
final usersReference = Firestore.instance.collection(“users”);
final StorageReference storageReference = FirebaseStorage.instance.ref().child(“Posts Pictures”);
final postsReference = Firestore.instance.collection(“posts”);
final activityFeedReference = Firestore.instance.collection(“feed”);
final commentsReference = Firestore.instance.collection(“comments”);
final followersReference = Firestore.instance.collection(“followers”);
final followingReference = Firestore.instance.collection(“following”);
final timelineReference = Firestore.instance.collection(“timeline”);

final DateTime timestamp = DateTime.now();
User currentUser;

class HomePage extends StatefulWidget {
@override
_HomePageState createState() => _HomePageState();
}

class _HomePageState extends State
{
bool isSignedIn = false;
PageController pageController;
int getPageIndex = 0;
FirebaseMessaging _firebaseMessaging = FirebaseMessaging();
final _scaffoldKey = GlobalKey();

void initState(){
super.initState();

pageController = PageController();

gSignIn.onCurrentUserChanged.listen((gSigninAccount){
  controlSignIn(gSigninAccount);
}, onError: (gError){
  print("Error Message: " + gError);
});

gSignIn.signInSilently(suppressErrors: false).then((gSignInAccount){
  controlSignIn(gSignInAccount);
}).catchError((gError){
  print("Error Message: " + gError);
});

}

controlSignIn(GoogleSignInAccount signInAccount) async
{
if(signInAccount != null)
{
await saveUserInfoToFireStore();

  setState(() {
    isSignedIn = true;
  });

  configureRealTimePushNotifications();
}
else
{
  setState(() {
    isSignedIn = false;
  });
}

}

configureRealTimePushNotifications()
{
final GoogleSignInAccount gUser = gSignIn.currentUser;

if(Platform.isIOS)
{
  getIOSPermissions();
}

_firebaseMessaging.getToken().then((token){
  usersReference.document(gUser.id).updateData({"androidNotificationToken": token});
});

_firebaseMessaging.configure(
  onMessage: (Map<String, dynamic> msg) async
  {
    final String recipientId = msg["data"]["recipient"];
    final String body = msg["notification"]["body"];

    if(recipientId == gUser.id)
    {
      SnackBar snackBar = SnackBar(
        backgroundColor: Colors.grey,
        content: Text(body, style: TextStyle(color: Colors.black), overflow: TextOverflow.ellipsis,),
      );
      _scaffoldKey.currentState.showSnackBar(snackBar);
    }
  },
);

}

getIOSPermissions()
{
_firebaseMessaging.requestNotificationPermissions(IosNotificationSettings(alert: true, badge: true, sound: true));

_firebaseMessaging.onIosSettingsRegistered.listen((settings){
  print("Settings Registered :  $settings");
});

}

saveUserInfoToFireStore() async {
final GoogleSignInAccount gCurrentUser = gSignIn.currentUser;
DocumentSnapshot documentSnapshot = await usersReference.document(gCurrentUser.id).get();

if(!documentSnapshot.exists){
  final username = await Navigator.push(context, MaterialPageRoute(builder: (context) => CreateAccountPage()));

  usersReference.document(gCurrentUser.id).setData({
    "id": gCurrentUser.id,
    "profileName": gCurrentUser.displayName,
    "username": username,
    "url": gCurrentUser.photoUrl,
    "email": gCurrentUser.email,
    "bio": "",
    "timestamp": timestamp,
  });

  await followersReference.document(gCurrentUser.id).collection("userFollowers").document(gCurrentUser.id).setData({});

  documentSnapshot = await usersReference.document(gCurrentUser.id).get();
}

currentUser = User.fromDocument(documentSnapshot);

}

void dispose(){
pageController.dispose();
super.dispose();
}

loginUser(){
gSignIn.signIn();
}

logoutUser(){
gSignIn.signOut();
}

whenPageChanges(int pageIndex){
setState(() {
this.getPageIndex = pageIndex;
});
}

onTapChangePage(int pageIndex){
pageController.animateToPage(pageIndex, duration: Duration(milliseconds: 400), curve: Curves.bounceInOut,);
}

Scaffold buildHomeScreen(){
return Scaffold(
key: _scaffoldKey,
body: PageView(
children: [
TimeLinePage(gCurrentUser: currentUser,),
SearchPage(),
UploadPage(gCurrentUser: currentUser,),
NotificationsPage(),
ProfilePage(userProfileId: currentUser?.id),
],
controller: pageController,
onPageChanged: whenPageChanges,
physics: NeverScrollableScrollPhysics(),
),
bottomNavigationBar: CupertinoTabBar(
currentIndex: getPageIndex,
onTap: onTapChangePage,
backgroundColor: Theme.of(context).accentColor,
activeColor: Colors.white,
inactiveColor: Colors.blueGrey,
items: [
BottomNavigationBarItem(icon: Icon(Icons.home)),
BottomNavigationBarItem(icon: Icon(Icons.search)),
BottomNavigationBarItem(icon: Icon(Icons.photo_camera, size: 37.0,)),
BottomNavigationBarItem(icon: Icon(Icons.favorite)),
BottomNavigationBarItem(icon: Icon(Icons.person)),
],
),
);
}

Scaffold buildSignInScreen(){
return Scaffold(
body: Container(
decoration: BoxDecoration(
gradient: LinearGradient(
begin: Alignment.topRight,
end: Alignment.bottomLeft,
colors: [Theme.of(context).accentColor, Theme.of(context).primaryColor],
),
),
alignment: Alignment.center,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Text(
“BuddiesGram”,
style: TextStyle(fontSize: 92.0, color: Colors.white, fontFamily: “Signatra”),
),
GestureDetector(
onTap: loginUser,
child: Container(
width: 270.0,
height: 65.0,
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage(“assets/images/google_signin_button.png”),
fit: BoxFit.cover,
),
),
),
),
],
),
),
);
}

@override
Widget build(BuildContext context) {
if(isSignedIn)
{
return buildHomeScreen();
}
else
{
return buildSignInScreen();
}
}
}

idk if someone can help me with these informations but im just a bit annoyed rn

Is there a repository to see the whole project? If not, please create a Gist with proper syntax highlighting.

Im new on Github and i dont know how to highlight the proper syntax. But the important files are TimeLinePage i think and HomePage

Thats not every dartfile, if you need more let me know. And thanks for your help