flutter-pwa-test/lib/Content.dart

import 'package:flutter/material.dart';
import 'package:geolocator/geolocator.dart';

class Content extends StatefulWidget {
  const Content({Key? key}) : super(key: key);

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

class _ContentState extends State<Content> {
  String? _coordinates;

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          ElevatedButton(
            child: Text("Test coordinates"),
            onPressed: () async {
              try {
                _coordinates = (await _getLocationAsync()).toString();
                setState(() {});
              } catch (e) {
                _coordinates = e.toString();
                setState(() {});
              }
            },
          ),
          _coordinates != null
              ? Text(_coordinates!.toString())
              : const SizedBox(),
        ],
      ),
    );
  }

  Future<Position> _getLocationAsync() async {
    bool serviceEnabled;
    LocationPermission permission;

    showDialog<void>(
      context: context,
      builder: (BuildContext dialogContext) {
        return const SimpleDialog(
          children: [
            Center(
              child: CircularProgressIndicator(),
            ),
          ],
        );
      },
    );

    // Test if location services are enabled.
    serviceEnabled = await Geolocator.isLocationServiceEnabled();
    if (!serviceEnabled) {
      // Location services are not enabled don't continue
      // accessing the position and request users of the
      // App to enable the location services.
      return Future.error('Location services are disabled.');
    }

    permission = await Geolocator.checkPermission();
    if (permission == LocationPermission.denied) {
      permission = await Geolocator.requestPermission();
      if (permission == LocationPermission.denied) {
        // Permissions are denied, next time you could try
        // requesting permissions again (this is also where
        // Android's shouldShowRequestPermissionRationale
        // returned true. According to Android guidelines
        // your App should show an explanatory UI now.
        return Future.error('Location permissions are denied');
      }
    }

    if (permission == LocationPermission.deniedForever) {
      // Permissions are denied forever, handle appropriately.
      return Future.error(
          'Location permissions are permanently denied, we cannot request permissions.');
    }

    // When we reach here, permissions are granted and we can
    // continue accessing the position of the device.
    var position = await Geolocator.getCurrentPosition();
    Navigator.pop(context);
    return position;
  }
}