HomeScreenState.dart

import 'package:flutter/services.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';
import 'dart:async';
import 'HomeScreenPage.dart';
import 'package:location/location.dart' as LocationMgr;

class HomeScreenState extends State<HomeScreenPage> {
  static const platformChannelGeolocator = const MethodChannel('geolocator');
  
  ...
  
  Future tapInMap(LatLng latLng) async {
    if (readingLocationOfCourse) {
      try {
        final String result = await platformChannelGeolocator.invokeMethod(
            'geolocator', <String, dynamic>{
              'latitude': latLng.latitude,
              'longitude': latLng.longitude
            });
        print('Geolocator is $result.');
      } on PlatformException catch (e) {
        print('Geolocator with problem: ${e.message}.');
      }
    }

  }

  ...
}