static async Task <GeoPosition> TryGetCurrentPosition(double desiredAccuracy, int timeout)
{
if (!IsTracking)
{
return(await ObtainCurrentPosition(desiredAccuracy, timeout));
}
var source = new TaskCompletionSource <GeoPosition>();
// We're already listening, just use the current listener
if (LastPosition == null)
{
Task gotPosition(GeoPosition p)
{
source.TrySetResult(p);
PositionChanged.RemoveHandler(gotPosition);
return(Task.CompletedTask);
}
PositionChanged.Handle(gotPosition);
}
else
{
source.TrySetResult(LastPosition);
}
return(await source.Task);
}
static async Task <GeoPosition> TryGetCurrentPosition(double desiredAccuracy, int timeout)
{
TaskCompletionSource <GeoPosition> tcs;
if (!IsTracking)
{
var manager = await CreateManager();
if (manager == null)
{
return(null);
}
if (await Device.Permissions.Check(Permission.BackgroundLocation) == PermissionResult.Granted)
{
manager.AllowsBackgroundLocationUpdates = true;
}
// We need a single update.
if (Device.OS.IsAtLeastiOS(6))
{
manager.PausesLocationUpdatesAutomatically = false;
}
tcs = new TaskCompletionSource <GeoPosition>(manager);
using (var singleListener = new GeoLocationSingleUpdateDelegate(manager, desiredAccuracy, timeout))
{
manager.AuthorizationChanged += (object sender, CLAuthorizationChangedEventArgs e) => singleListener.AuthorizationChanged(manager, e.Status);
manager.Failed += (object sender, NSErrorEventArgs e) => singleListener.Failed(manager, e.Error);
manager.UpdatedHeading += (object sender, CLHeadingUpdatedEventArgs e) => singleListener.UpdatedHeading(manager, e.NewHeading);
manager.UpdatedLocation += (object sender, CLLocationUpdatedEventArgs e) => singleListener.UpdatedLocation(manager, e.NewLocation, e.OldLocation);
manager.StartUpdatingLocation();
var result = await singleListener.TaskSource.Task;
}
}
tcs = new TaskCompletionSource <GeoPosition>();
Task gotError(Exception ex)
{
tcs.TrySetException(ex);
PositionError.RemoveHandler(gotError);
return(Task.CompletedTask);
}
PositionError.Handle(gotError);
Task gotPosition(GeoPosition position)
{
tcs.TrySetResult(position);
PositionChanged.RemoveHandler(gotPosition);
return(Task.CompletedTask);
}
PositionChanged.Handle(gotPosition);
return(await tcs.Task);
}