feat: Add features to the sample

src/GeolocatorService.Reactive/GeolocatorServiceExtensions.cs

@@ -58,11 +58,17 @@ public static IObservable<bool> ObserveIsPermissionGranted(this IGeolocatorServi
 		/// <summary>
 		/// Gets and observes the location permission. Requests the permission if this was not already done.
 		/// </summary>
-		public static async Task<IObservable<bool>> GetAndObserveIsPermissionGranted(this IGeolocatorService service, CancellationToken ct)
+		public static IObservable<bool> GetAndObserveIsPermissionGranted(this IGeolocatorService service)
 		{
-			var isPermissionGranted = await service.RequestPermission(ct);
+			var initialPermission = Observable.Create<bool>(service.GetInitialPermission);
+
+			return ObserveIsPermissionGranted(service).Merge(initialPermission);
+		}
 
-			return ObserveIsPermissionGranted(service).StartWith(isPermissionGranted);
+		private static async Task GetInitialPermission(this IGeolocatorService service, IObserver<bool> observer, CancellationToken ct)
+		{
+			var isPermissionGranted = await service.RequestPermission(ct);
+			observer.OnNext(isPermissionGranted);
 		}
 	}
 }

src/GeolocatorService.Samples/GeolocatorService.Samples.Shared/MainPage.xaml

@@ -7,12 +7,18 @@
 	  mc:Ignorable="d">
 
 	<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
-		<StackPanel Margin="0,40,0,0">
+		<StackPanel Margin="0,40,0,0"
+					Spacing="20">
 
 			<Button Content="Request permission"
 					Command="{Binding RequestPermissionCommand}" />
 
 			<TextBlock Text="{Binding PageContent}" />
+
+			<Button Content="Get location"
+					Command="{Binding GetLocation}" />
+
+			<TextBlock Text="{Binding PermissionStatus}" />
 		</StackPanel>
 	</Grid>
 </Page>

src/GeolocatorService.Samples/GeolocatorService.Samples.Shared/MainPageViewModel.cs

@@ -12,7 +12,8 @@ public class MainPageViewModel : INotifyPropertyChanged
 	{
 		private CoreDispatcher _dispatcher;
 		private IGeolocatorService _geolocatorService;
-		private IDisposable _subscription = null;
+		private IDisposable _locationOrNullSubscription = null;
+		private IDisposable _permissionSubscription = null;
 
 		public event PropertyChangedEventHandler PropertyChanged;
 
@@ -48,10 +49,36 @@ private void SetPageContent(string content)
 			}
 		}
 
+		private string _permissionStatus = "";
+		public string PermissionStatus
+		{
+			get => _permissionStatus;
+			set
+			{
+				_permissionStatus = value;
+				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(PermissionStatus)));
+			}
+		}
+
+		private void SetPermissionStatus(string content)
+		{
+			if (_dispatcher.HasThreadAccess)
+			{
+				PermissionStatus = content;
+			}
+			else
+			{
+				_ = _dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
+				{
+					SetPermissionStatus(content);
+				});
+			}
+		}
+
 		public DelegateCommand RequestPermissionCommand => new DelegateCommand(() =>
 		{
-			_subscription = _geolocatorService.
-				GetAndObserveLocationOrDefault()
+			_locationOrNullSubscription = _geolocatorService
+				.GetAndObserveLocationOrDefault()
 				.Subscribe(
 					location =>
 					{
@@ -69,6 +96,39 @@ private void SetPageContent(string content)
 						SetPageContent($"An error has occurred: {error}");
 					}
 				);
+
+			_permissionSubscription = _geolocatorService
+				.GetAndObserveIsPermissionGranted()
+				.Subscribe(
+					isGranted =>
+					{
+						if (isGranted)
+						{
+							SetPermissionStatus("Permission: Granted");
+						}
+						else
+						{
+							SetPermissionStatus($"Permission: Denied");
+						}
+					},
+					error =>
+					{
+						SetPermissionStatus($"An error has occurred: {error}");
+					}
+				);
+		});
+
+		public DelegateCommand GetLocationCommand => new DelegateCommand(async () =>
+		{
+			try
+			{
+				var location = await _geolocatorService.GetLocation(CancellationToken.None);
+				SetPageContent($"GetLocation- ({location.Point.Position.Longitude}, {location.Point.Position.Latitude})");
+			}
+			catch(Exception ex)
+			{
+				SetPageContent($"GetLocation- An error has occurred : {ex}");
+			}
 		});
 
 		public class DelegateCommand : ICommand