Flutter refresh map after come back from second screen

Question

I have a Flutter app which in home screen I use google map. At the begin, I call Firebase to take the places which I have already input. Then the user can add a new place if double in the map this lead him to SecondScreen. The user input title, story, and photo. I have and another screen where the user can view info for existing marker where can also delete it. My problem is when user input or delete marker and come back to the home page, in the map, the places are not refreshed and I see that the Firebase is not called again. How can I solve this problem? The Firebase is called in MapsDemo class My code:

import 'dart:ui' as ui;
import  'dart:io';
import 'dart:convert';

import 'package:http/http.dart' as http;

import 'package:flutter/material.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';
import 'package:geolocator/geolocator.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_storage/firebase_storage.dart';
import 'package:image_picker/image_picker.dart';
import 'package:uuid/uuid.dart';

import 'infopage.dart';

void main() {

  GoogleMapController.init();
  final size = MediaQueryData.fromWindow(ui.window).size;
  final GoogleMapOverlayController controller =
      GoogleMapOverlayController.fromSize(
    width: size.width,
    height: size.height,
  );

  final mapController = controller.mapController;
////  Set firebase https://www.youtube.com/watch?v=DqJ_KjFzL9I
////  TODO check if every time I come back the above commands call
//  Firestore.instance.collection('Stories').snapshots().listen((data) =>
//      data.documents.forEach((doc) =>
////Read all the markers from firebase and add them to map
//
//          AddMarkers(mapController, ConvertCoordinates(doc["lat"], doc["lng"]),
//              doc["title"], doc["story"], doc["url"])));



  final Widget mapWidget = GoogleMapOverlay(controller: controller);


  runApp(

    MaterialApp(
      home: new Scaffold(
        appBar: AppBar(
          title: TextField(
            decoration: InputDecoration.collapsed(hintText: 'Search'),
          ),
          actions: <Widget>[
            IconButton(
              icon: const Icon(Icons.my_location),
              onPressed: () async {
                Position position = await Geolocator()
                    .getCurrentPosition(desiredAccuracy: LocationAccuracy.high);
//                Get my current position
                final location = LatLng(position.latitude, position.longitude);
                mapController.markers.clear();
                mapController.addMarker(MarkerOptions(
                    position: location,
                    infoWindowText: InfoWindowText("Here you are!", "Add me"),
                    visible: true));
                mapController.animateCamera(
                  CameraUpdate.newLatLngZoom(location, 20.0),
                );
              },
            ),
          ],
        ),
        body: MapsDemo(mapWidget, controller.mapController),
        floatingActionButton: FloatingActionButton(
          onPressed: () {},
          child: const Icon(Icons.my_location),
        ),
      ),
      navigatorObservers: <NavigatorObserver>[controller.overlayController],
    ),
  );
}

class MapsDemo extends StatelessWidget {
  MapsDemo(this.mapWidget, this.controller);

  final Widget mapWidget;
  final GoogleMapController controller;

  @override
  Widget build(BuildContext context) {
//  Set firebase https://www.youtube.com/watch?v=DqJ_KjFzL9I
//  TODO check if every time I come back the above commands call
    Firestore.instance.collection('Stories').snapshots().listen((data) =>
        data.documents.forEach((doc) =>
//Read all the markers from firebase and add them to map

        AddMarkers(controller, ConvertCoordinates(doc["lat"], doc["lng"]),
            doc["title"], doc["story"], doc["url"])));

    controller.onMarkerTapped.add((Marker marker) async {
//Marker listener open new page info page

      String titlos = marker.options.infoWindowText.title;





      if (titlos != "Here you are!") {
        String story = marker.options.infoWindowText.snippet.split("?")[0];
        String url = marker.options.infoWindowText.snippet.split("?")[1];
        String realUrl = await makeRequest(url);
        String downloadUrl =getDownloadUrl(realUrl,url);

        Navigator.push(
//        Parse title to next page/screen

            context,
            new MaterialPageRoute(
                builder: (context) =>
                    new AboutPage(title: titlos, story: story, url: downloadUrl,)));
      } else {

        Navigator.push(
//        Parse title to next page/screen
            context,
            new MaterialPageRoute(builder: (context) => new SecondScreen(
                marker.options.position.latitude.toString(),
                marker.options.position.longitude.toString())));
      }
    });
    return Center(child: mapWidget);
  }
}

LatLng ConvertCoordinates(String lat, String lng) {
// Convert strings coordinates to LatLng
  return LatLng(double.parse(lat), double.parse(lng));
}

void AddMarkers(GoogleMapController map, LatLng coor, String title,
    String story, String url) {
  map.addMarker(MarkerOptions(
      position: coor, infoWindowText: InfoWindowText(title, '$story'+'?'+'$url')));
}



Future<String> makeRequest(String n) async {
  String baseUrl = 'https://firebasestorage.googleapis.com/v0/b/storymap-da000.appspot.com/o/';
  String url = '$baseUrl' + '$n';
  var client = new http.Client();
  final response = await client.get(url);


return response.body;
}


String getDownloadUrl(String url, String name){
  String baseUrl = 'https://firebasestorage.googleapis.com/v0/b/storymap-da000.appspot.com/o/';
  String token =  url.replaceAll("{", "").replaceAll("}", "").split('"downloadTokens": ')[1].replaceAll('"', '');
  return '$baseUrl'+'$name'+"?alt=media&token="+'$token';

}

class SecondScreen extends StatelessWidget {
  final String lat;
  final String lng;
//  final String image_name;
  final titleC = TextEditingController();
  final storyC = TextEditingController();
  static final String image_name = Uuid().v1();




  SecondScreen(this.lat, this.lng,);
  Future getImage() async {
    var image = await ImagePicker.pickImage(source: ImageSource.camera);
    final StorageReference firebaseStorageRef =
    FirebaseStorage.instance.ref().child(image_name);
    final StorageUploadTask task =
    firebaseStorageRef.putFile(image);
  }

  uploadFirebase(){

    var map= {
      "title":titleC.text,
      "story":storyC.text,
      "url":image_name,
      "lat":lat,
      "lng":lng
    };

    Firestore.instance.collection('Stories').document()
        .setData(map);
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Second Screen"),
      ),
      body: Center(
        child: new Column(
    mainAxisAlignment: MainAxisAlignment.center,
    children: <Widget>[
          new TextField (
            controller: titleC,
          ),
      new TextField(
        controller: storyC,
      ),
          new RaisedButton(
            onPressed: () => getImage(),
            child: new Text('Take photo'),

          ),
          new RaisedButton(
            onPressed: () => uploadFirebase(),
            child: new Text('Confirm'),

          )

    ])
      ),
    );
  }
}

[Edit] I change my code to this,

import 'dart:ui' as ui;
import  'dart:io';
import 'dart:convert';

import 'package:http/http.dart' as http;

import 'package:flutter/material.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';
import 'package:geolocator/geolocator.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_storage/firebase_storage.dart';
import 'package:image_picker/image_picker.dart';
import 'package:uuid/uuid.dart';

import 'infopage.dart';

void main() {

  GoogleMapController.init();
  final size = MediaQueryData.fromWindow(ui.window).size;
  final GoogleMapOverlayController controller =
  GoogleMapOverlayController.fromSize(
    width: size.width,
    height: size.height,
  );

  final mapController = controller.mapController;
////  Set firebase https://www.youtube.com/watch?v=DqJ_KjFzL9I
////  TODO check if every time I come back the above commands call
//  Firestore.instance.collection('Stories').snapshots().listen((data) =>
//      data.documents.forEach((doc) =>
////Read all the markers from firebase and add them to map
//
//          AddMarkers(mapController, ConvertCoordinates(doc["lat"], doc["lng"]),
//              doc["title"], doc["story"], doc["url"])));



  final Widget mapWidget = GoogleMapOverlay(controller: controller);


  runApp(

    MaterialApp(
      home: new Scaffold(
        appBar: AppBar(
          title: TextField(
            decoration: InputDecoration.collapsed(hintText: 'Search'),
          ),
          actions: <Widget>[
            IconButton(
              icon: const Icon(Icons.my_location),
              onPressed: () async {
                Position position = await Geolocator()
                    .getCurrentPosition(desiredAccuracy: LocationAccuracy.high);
//                Get my current position
                final location = LatLng(position.latitude, position.longitude);
                mapController.markers.clear();
                mapController.addMarker(MarkerOptions(
                    position: location,
                    infoWindowText: InfoWindowText("Here you are!", "Add me"),
                    visible: true,draggable: true));
                mapController.animateCamera(
                  CameraUpdate.newLatLngZoom(location, 20.0),
                );
              },
            ),
            IconButton(
              icon: const Icon(Icons.refresh),
              onPressed: () {RefreshIt(mapController);},
            )
          ],
        ),
        body: _MapDemo(mapWidget:mapWidget, controller:controller.mapController),

      ),
      navigatorObservers: <NavigatorObserver>[controller.overlayController],
    ),
  );
}
class _MapDemo extends StatefulWidget{
final Widget mapWidget;
final GoogleMapController controller;

const _MapDemo({Key key, this.mapWidget, this.controller}) : super(key: key);
@override
MapsDemo createState() => MapsDemo(this.mapWidget, this.controller);



}
class MapsDemo extends State<_MapDemo> {
  MapsDemo(this.mapWidget, this.controller);

  final Widget mapWidget;
  final GoogleMapController controller;

  @override
  Widget build(BuildContext context) {
//  Set firebase https://www.youtube.com/watch?v=DqJ_KjFzL9I
  controller.markers.clear();
//  TODO check if every time I come back the above commands call
    Firestore.instance.collection('Stories').snapshots().listen((data) =>
        data.documents.forEach((doc) =>
//Read all the markers from firebase and add them to map

        AddMarkers(controller, ConvertCoordinates(doc["lat"], doc["lng"]),
            doc["title"], doc["story"], doc["url"])));

    controller.onMarkerTapped.add((Marker marker) async {
//Marker listener open new page info page

      String titlos = marker.options.infoWindowText.title;





      if (titlos != "Here you are!") {
        String story = marker.options.infoWindowText.snippet.split("?")[0];
        String url = marker.options.infoWindowText.snippet.split("?")[1];
        String realUrl = await makeRequest(url);
        String downloadUrl =getDownloadUrl(realUrl,url);

        Navigator.push(
//        Parse title to next page/screen

            context,
            new MaterialPageRoute(
                builder: (context) =>
                new AboutPage(title: titlos, story: story, url: downloadUrl,)));
      } else {

        Navigator.push(
//        Parse title to next page/screen
            context,
            new MaterialPageRoute(builder: (context) => new _SecondScreen(
                lat:marker.options.position.latitude.toString(),
                lng:marker.options.position.longitude.toString())));
      }
    });
    return Center(child: mapWidget);
  }
}

LatLng ConvertCoordinates(String lat, String lng) {
// Convert strings coordinates to LatLng
  return LatLng(double.parse(lat), double.parse(lng));
}

void AddMarkers(GoogleMapController map, LatLng coor, String title,
    String story, String url) {
  map.addMarker(MarkerOptions(
      position: coor, infoWindowText: InfoWindowText(title, '$story'+'?'+'$url')));
}

void RefreshIt(GoogleMapController mapController){
//TODO Refresh the map via this float button



}

Future<String> makeRequest(String n) async {
  String baseUrl = 'https://firebasestorage.googleapis.com/v0/b/storymap-da000.appspot.com/o/';
  String url = '$baseUrl' + '$n';
  var client = new http.Client();
  final response = await client.get(url);


  return response.body;
}


String getDownloadUrl(String url, String name){
  String baseUrl = 'https://firebasestorage.googleapis.com/v0/b/storymap-da000.appspot.com/o/';
  String token =  url.replaceAll("{", "").replaceAll("}", "").split('"downloadTokens": ')[1].replaceAll('"', '');
  return '$baseUrl'+'$name'+"?alt=media&token="+'$token';

}
class _SecondScreen extends StatefulWidget{
  final String lat;
  final String lng;

  const _SecondScreen({Key key, this.lat, this.lng}) : super(key: key);
  @override
  SecondScreen createState() => SecondScreen(this.lat, this.lng);



}
class SecondScreen extends State<_SecondScreen> {
  final String lat;
  final String lng;
//  final String image_name;
  final titleC = TextEditingController();
  final storyC = TextEditingController();
  static final String image_name = Uuid().v1();




  SecondScreen(this.lat, this.lng,);
  Future getImage() async {
    var image = await ImagePicker.pickImage(source: ImageSource.camera);
    final StorageReference firebaseStorageRef =
    FirebaseStorage.instance.ref().child(image_name);
    final StorageUploadTask task =
    firebaseStorageRef.putFile(image);
  }

  uploadFirebase(){

    var map= {
      "title":titleC.text,
      "story":storyC.text,
      "url":image_name,
      "lat":lat,
      "lng":lng
    };

    Firestore.instance.collection('Stories').document()
        .setData(map);
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Input Screen"),
      ),
      body: Center(
          child: new Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                new TextField (
                  controller: titleC,
                ),
                new TextField(
                  controller: storyC,
                ),
                new RaisedButton(
                  onPressed: () => getImage(),
                  child: new Text('Take photo'),

                ),
                new RaisedButton(
                  onPressed: () => uploadFirebase(),
                  child: new Text('Confirm'),

                )

              ])
      ),
    );
  }
}

My firebase is shared with a website with the same concept, when I add something in the website the new marker is appeared in my Flutter app, but not when I delete a marker. On the other hand, when I add or remove marker from my Flutter app I don't get any refresh in my map... Any idea?

Answer 1

I set the mapStyle after resuming app from background and it worked for me:

mapController.setMapStyle("[]");

Answer 2

All of your widgets are Stateless which means they won't be able to update or change upon user interaction. This tutorial from the Flutter documentation goes through how to add interactivity to your app using Stateful widgets which will solve your problem.