Geolocator didChangeAppLifecycleState loop issue

main.dart

import 'dart:async';

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

/// Defines the main theme color.
final MaterialColor themeMaterialColor =
BaseflowPluginExample.createMaterialColor(
    const Color.fromRGBO(48, 49, 60, 1));

void main() {
  runApp(BaseflowPluginExample(
    pluginName: 'Geolocator',
    githubURL: 'https://github.com/Baseflow/flutter-geolocator',
    pubDevURL: 'https://pub.dev/packages/geolocator',
    pages: [GeolocatorWidget.createPage()],
  ));
}

/// Example [Widget] showing the functionalities of the geolocator plugin
class GeolocatorWidget extends StatefulWidget {
  /// Utility method to create a page with the Baseflow templating.
  static ExamplePage createPage() {
    return ExamplePage(Icons.location_on, (context) => GeolocatorWidget());
  }

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

class _GeolocatorWidgetState extends State<GeolocatorWidget> with WidgetsBindingObserver {
  final List<_PositionItem> _positionItems = <_PositionItem>[];
  StreamSubscription<Position> _positionStreamSubscription;

  @override
  void initState() {
    WidgetsBinding.instance.addObserver(this);
    super.initState();
  }



  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Theme.of(context).backgroundColor,
      body: ListView.builder(
        itemCount: _positionItems.length,
        itemBuilder: (context, index) {
          final positionItem = _positionItems[index];

          if (positionItem.type == _PositionItemType.permission) {
            return ListTile(
              title: Text(positionItem.displayValue,
                  textAlign: TextAlign.center,
                  style: TextStyle(
                    color: Colors.white,
                    fontWeight: FontWeight.bold,
                  )),
            );
          } else {
            return Card(
              child: ListTile(
                tileColor: themeMaterialColor,
                title: Text(
                  positionItem.displayValue,
                  style: TextStyle(color: Colors.white),
                ),
              ),
            );
          }
        },
      ),
      floatingActionButton: Stack(
        children: <Widget>[
          Positioned(
            bottom: 10.0,
            right: 10.0,
            child: FloatingActionButton.extended(
              onPressed: () => setState(_positionItems.clear),
              label: Text("clear"),
            ),
          ),
          Positioned(
            bottom: 80.0,
            right: 10.0,
            child: FloatingActionButton.extended(
              onPressed: () async {
                await Geolocator.getLastKnownPosition().then((value) => {
                  _positionItems.add(_PositionItem(
                      _PositionItemType.position, value.toString()))
                });

                setState(
                      () {},
                );
              },
              label: Text("Last Position"),
            ),
          ),
          Positioned(
            bottom: 150.0,
            right: 10.0,
            child: FloatingActionButton.extended(
                onPressed: () async {
                  await Geolocator.getCurrentPosition().then((value) => {
                    _positionItems.add(_PositionItem(
                        _PositionItemType.position, value.toString()))
                  });

                  setState(
                        () {},
                  );
                },
                label: Text("Current Position")),
          ),
          Positioned(
            bottom: 220.0,
            right: 10.0,
            child: FloatingActionButton.extended(
              onPressed: _toggleListening,
              label: Text(() {
                if (_positionStreamSubscription == null) {
                  return "Start stream";
                } else {
                  final buttonText = _positionStreamSubscription.isPaused
                      ? "Resume"
                      : "Pause";

                  return "$buttonText stream";
                }
              }()),
              backgroundColor: _determineButtonColor(),
            ),
          ),
          Positioned(
            bottom: 290.0,
            right: 10.0,
            child: FloatingActionButton.extended(
              onPressed: () async {
                await Geolocator.checkPermission().then((value) => {
                  _positionItems.add(_PositionItem(
                      _PositionItemType.permission, value.toString()))
                });
                setState(() {});
              },
              label: Text("Check Permission"),
            ),
          ),
          Positioned(
            bottom: 360.0,
            right: 10.0,
            child: FloatingActionButton.extended(
              onPressed: () async {
                await Geolocator.requestPermission().then((value) => {
                  _positionItems.add(_PositionItem(
                      _PositionItemType.permission, value.toString()))
                });
                setState(() {});
              },
              label: Text("Request Permission"),
            ),
          ),
        ],
      ),
    );
  }

  bool _isListening() => (_positionStreamSubscription == null ||
      _positionStreamSubscription.isPaused);

  Color _determineButtonColor() {
    return _isListening() ? Colors.green : Colors.red;
  }

  void _toggleListening() {
    if (_positionStreamSubscription == null) {
      final positionStream = Geolocator.getPositionStream();
      _positionStreamSubscription = positionStream.handleError((error) {
        _positionStreamSubscription?.cancel();
        _positionStreamSubscription = null;
      }).listen((position) => setState(() => _positionItems.add(
          _PositionItem(_PositionItemType.position, position.toString()))));
      _positionStreamSubscription?.pause();
    }

    setState(() {
      if (_positionStreamSubscription == null) {
        return;
      }

      if (_positionStreamSubscription.isPaused) {
        _positionStreamSubscription.resume();
      } else {
        _positionStreamSubscription.pause();
      }
    });
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    if (_positionStreamSubscription = null) {
      _positionStreamSubscription.cancel();
      _positionStreamSubscription = null;
    }

    super.dispose();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    print("_didChangeAppLifecycleState: $state");
  }
}

enum _PositionItemType {
  permission,
  position,
}

class _PositionItem {
  _PositionItem(this.type, this.displayValue);

  final _PositionItemType type;
  final String displayValue;
}

pubspec.yaml

name: flutter_sample_app
description: A new Flutter application.

# The following line prevents the package from being accidentally published to
# pub.dev using `pub publish`. This is preferred for private packages.
publish_to: 'none' # Remove this line if you wish to publish to pub.dev

# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
version: 1.0.0+1

environment:
  sdk: ">=2.10.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter
  geolocator: ^7.0.3
  baseflow_plugin_template:
    git:
      url: git://github.com/Baseflow/baseflow_plugin_template.git
      ref: v2.0.0-nullsafety

  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^1.0.2

dev_dependencies:
  flutter_test:
    sdk: flutter

# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec

# The following section is specific to Flutter.
flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  # assets:
  #   - images/a_dot_burr.jpeg
  #   - images/a_dot_ham.jpeg

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/assets-and-images/#resolution-aware.

  # For details regarding adding assets from package dependencies, see
  # https://flutter.dev/assets-and-images/#from-packages

  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  # fonts:
  #   - family: Schyler
  #     fonts:
  #       - asset: fonts/Schyler-Regular.ttf
  #       - asset: fonts/Schyler-Italic.ttf
  #         style: italic
  #   - family: Trajan Pro
  #     fonts:
  #       - asset: fonts/TrajanPro.ttf
  #       - asset: fonts/TrajanPro_Bold.ttf
  #         weight: 700
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.dev/custom-fonts/#from-packages