/// <summary>
/// Gets the last reading (can be filtered out by maxAgeOfLastReading) otherwise request the current reading
/// </summary>
/// <param name="gpsManager"></param>
/// <param name="maxAgeOfLastReading"></param>
/// <returns></returns>
public static IObservable <IGpsReading> GetLastReadingOrCurrentPosition(this IGpsManager gpsManager, DateTime?maxAgeOfLastReading = null) => Observable.FromAsync <IGpsReading>(async ct =>
{
var reading = await gpsManager.GetLastReading().ToTask(ct);
if (reading == null || (maxAgeOfLastReading != null && reading.Timestamp < maxAgeOfLastReading.Value))
{
reading = await gpsManager.GetCurrentPosition().ToTask(ct);
}
return(reading);
});
