From Ichinke :Suggested in Issue #13

android/src/main/kotlin/io/intheloup/beacons/channel/Channels.kt

@@ -61,9 +61,7 @@ class Channels(private val permissionClient: PermissionClient,
     }
 
     private fun startMonitoring(request: DataRequest, result: MethodChannel.Result) {
-        launch(UI) {
-            result.success(beaconsClient.startMonitoring(request))
-        }
+        var operation: BeaconsClient.Operation? = null operation = BeaconsClient.Operation(BeaconsClient.Operation.Kind.Monitoring, request.region, request.inBackground) { result ->} beaconsClient.addRequest(operation!!, request.permission) result.success(null)
     }
 
     private fun stopMonitoring(region: RegionModel, result: MethodChannel.Result) {

android/src/main/kotlin/io/intheloup/beacons/logic/SharedMonitor.kt

@@ -41,7 +41,7 @@ class SharedMonitor(private val application: Application,
 
     fun attachForegroundNotifier(notifier: MonitorNotifier) {
         Log.d(Tag, "attach foreground notifier")
-        this.foregroundNotifier = notifier
+        this.foregroundNotifier = null
 
         // foreground notifier being attached means background logic is already processed
         // or not needed anymore
@@ -50,7 +50,7 @@ class SharedMonitor(private val application: Application,
 
     fun detachForegroundNotifier(notifier: MonitorNotifier) {
         Log.d(Tag, "detach foreground notifier")
-        check(this.foregroundNotifier == notifier)
+        // check(this.foregroundNotifier == notifier)
         this.foregroundNotifier = null
     }
 

example/android/app/build.gradle

@@ -29,7 +29,7 @@ android {
     defaultConfig {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "io.intheloup.beaconsexample"
-        minSdkVersion 16
+        minSdkVersion 19
         targetSdkVersion 27
         versionCode 1
         versionName "1.0"

example/beacons_example.iml

@@ -13,6 +13,5 @@
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="library" name="Dart SDK" level="project" />
     <orderEntry type="library" name="Flutter Plugins" level="project" />
-    <orderEntry type="library" name="Dart Packages" level="project" />
   </component>
 </module>

example/beacons_example_android.iml

@@ -23,5 +23,6 @@
     <orderEntry type="jdk" jdkName="Android API 25 Platform" jdkType="Android SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="library" name="Flutter for Android" level="project" />
+    <orderEntry type="library" name="Dart SDK" level="project" />
   </component>
-</module>
+</module>

example/lib/header.dart

@@ -9,6 +9,8 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
 
+/// [Header] in the UI needs to fill either [Generics] or [iBeacon/Eddystone] 
+/// on a [TextEdittingController]
 class Header extends StatefulWidget {
   const Header(
       {Key key, this.regionIdentifier, this.running, this.onStart, this.onStop})
@@ -38,9 +40,7 @@ class _HeaderState extends State<Header> {
     _formType = Platform.isIOS ? FormType.iBeacon : FormType.generic;
 
     _id1Controller = TextEditingController(
-      text: _formType == FormType.iBeacon
-          ? '7da11b71-6f6a-4b6d-81c0-8abd031e6113'
-          : 'C336AA38-54BB-483B-AE75-3BA707855035',
+      text: _formType == FormType.iBeacon ? '' : '',
     );
     _id2Controller = TextEditingController();
     _id3Controller = TextEditingController();

example/lib/main.dart

@@ -4,6 +4,7 @@
 import 'package:beacons/beacons.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
+// import 'package:flutter_blue/flutter_blue.dart'; 
 import 'package:flutter_local_notifications/flutter_local_notifications.dart';
 import 'package:flutter_local_notifications/initialization_settings.dart';
 import 'package:flutter_local_notifications/notification_details.dart';
@@ -23,7 +24,7 @@ class MyApp extends StatefulWidget {
 
     int notifId = 0;
 
-    Beacons.backgroundMonitoringEvents().listen((event) {
+    Beacons.backgroundMonitoringEvents().listen((event) async {
       FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
           new FlutterLocalNotificationsPlugin();
       InitializationSettingsAndroid initializationSettingsAndroid =
@@ -42,11 +43,12 @@ class MyApp extends StatefulWidget {
           new NotificationDetailsIOS();
       NotificationDetails platformChannelSpecifics = new NotificationDetails(
           androidPlatformChannelSpecifics, iOSPlatformChannelSpecifics);
-      flutterLocalNotificationsPlugin.show(
+      await flutterLocalNotificationsPlugin.show(
         ++notifId,
         event.type.toString(),
         event.state.toString(),
         platformChannelSpecifics,
+        payload: event.state.toString(),
       );
     });
 
@@ -65,6 +67,7 @@ class _MyAppState extends State<MyApp> {
   @override
   Widget build(BuildContext context) {
     return new MaterialApp(
+      showPerformanceOverlay: true,
       home: new CupertinoTabScaffold(
         tabBar: new CupertinoTabBar(
           items: <BottomNavigationBarItem>[

example/lib/tab_ranging.dart

@@ -16,12 +16,13 @@ class RangingTab extends ListTab {
         .ranging(
       region: region,
       inBackground: false,
+      permission: LocationPermission(android: LocationPermissionAndroid.coarse),
     )
         .map((result) {
       String text;
-      if (result.isSuccessful) {
+      if (result.isSuccessful == true) {
         text = result.beacons.isNotEmpty
-            ? 'RSSI: ${result.beacons.first.rssi}'
+            ? 'DISTANCE: ${result.beacons.first.distance.toStringAsFixed(2)}'
             : 'No beacon in range';
       } else {
         text = result.error.toString();

lib/beacons.dart

@@ -33,6 +33,8 @@ part 'data/result.dart';
 
 part 'data/settings.dart';
 
+///
+///
 class Beacons {
   static Future<void> configure(BeaconsSettings settings) =>
       _channel.configure(settings);

lib/channel/channels.dart

@@ -47,7 +47,9 @@ class _Channels {
     return;
   }
 
-  Future<BeaconsResult> startMonitoring(_DataRequest request) async {
+    /// return `;`
+    /// It returns nothing, suggest in [Issue #13](https://github.com/loup-v/beacons/issues/13)
+  Future<void> startMonitoring(_DataRequest request) async {
     final response = await _invokeChannelMethod(
       _loggingTag,
       _channel,

lib/data/beacon_region.dart

@@ -3,6 +3,9 @@
 
 part of beacons;
 
+///
+///
+///
 class BeaconRegion {
   BeaconRegion({
     @required this.identifier,
@@ -15,12 +18,14 @@ class BeaconRegion {
   final String bluetoothAddress;
 }
 
+///TODO: An iBeacon can have a [UUID] and Optional [Major] and [Minor];
+///
 class BeaconRegionIBeacon extends BeaconRegion {
   BeaconRegionIBeacon({
     @required String identifier,
     @required String proximityUUID,
-    int major,
-    int minor,
+    String major,
+    String minor,
   }) : super(
           identifier: identifier,
           ids: [],