public void OnLocationChanged(Android.Locations.Location location)
{
MarkerOptions currentPos = new MarkerOptions();
currentPos.SetPosition(new LatLng(location.Latitude, location.Longitude));
currentPos.SetIcon(BitmapDescriptorFactory.DefaultMarker(BitmapDescriptorFactory.HueAzure));
currentPos.SetTitle("Your Position");
_currentLocationMarker?.Remove();
if (MMap != null)
{
_currentLocationMarker = MMap.AddMarker(currentPos);
}
foreach (var marker in _markerList)
{
if (Location.CalculateDistance(new Location(location.Latitude, location.Longitude),
new Location(marker.Lat, marker.Lon), DistanceUnits.Kilometers) < marker.Dist)
{
if (!marker.Availability)
{
try
{
MailAddress from = new MailAddress("*****@*****.**", "XamarinApp");
MailAddress to = new MailAddress(user_email);
MailMessage m = new MailMessage(from, to)
{
Subject = "Location Tracking",
Body = $"<h2>You are near place named: {marker.Title}<h2>" +
$"Your latitude is {location.Latitude}, your longitude is {location.Longitude}",
IsBodyHtml = true
};
var smtp = new SmtpClient("smtp.gmail.com")
{
Credentials = new NetworkCredential("oop.exam.xam", ""),
EnableSsl = true
}; // password is not pulic.
smtp.Send(m);
marker.Availability = true;
}
catch
{
// ignored
}
}
}
else if (marker.Availability)
{
marker.Availability = false;
}
}
}
public static bool ShouldRefresh(Xamarin.Essentials.Location oldLocation, Xamarin.Essentials.Location newLocation)
{
if (newLocation == null)
{
return(false);
}
if (oldLocation == null)
{
return(true);
}
if (newLocation.Timestamp.Subtract(oldLocation.Timestamp)
> TimeSpan.FromMinutes(Constants.MainMapWeatherRefreshDuration))
{
return(true);
}
if (newLocation.CalculateDistance(oldLocation, DistanceUnits.Kilometers)
> Constants.MainMapWeatherRefreshDistance)
{
return(true);
}
return(false);
}
/// <summary>
/// Get the distance from another postion in km
/// </summary>
/// @author Gabriele Ursini
/// <returns> A distance </returns>
public double getDistance(Xamarin.Essentials.Location newPosition)
{
return(position.CalculateDistance(newPosition, DistanceUnits.Kilometers));
}
/// <summary>
/// Sends the user's location to the server if the distance is to the last request is larger than 10m, otherwise an exponential backoff occrus
/// Backoff = (previous backoff ^ 2)
/// </summary>
protected async void Track()
{
bool success = false;
int retry = 0;
retry = 0;
try
{
// TODO:
// faster they go, the more locations sent and slower they go the less
request = new GeolocationRequest(GeolocationAccuracy.Best);
Xamarin.Essentials.Location location = null;
if (Previous_request != null)
{
location = await Geolocation.GetLocationAsync(request);
Models.Location customLocation = new Models.Location(location);
if (!LocationService.LocationSavedToNotSend(customLocation))
{
if (location.CalculateDistance(Previous_request, DistanceUnits.Kilometers) >= MetersConsidedUserMoved)
{
await customLocation.GetRegion();
_Backoff = Initial_Backoff;
Track_Retry = 0;
SendUserLocation(customLocation);
}
else
{
ExtendBackoff();
SendUserLocation(customLocation);
}
}
else
{
ExtendBackoff();
}
}
else
{
location = await Geolocation.GetLocationAsync(request);
Models.Location customLocation = new Models.Location(location);
if ((!LocationService.LocationSavedToNotSend(customLocation)))
{
await customLocation.GetRegion();
SendUserLocation(customLocation);
}
}
Previous_request = location;
success = true;
}
catch (Exception e)
{
Debug.WriteLine(e.StackTrace);
//retry for getting the geolocation
retry++;
}
}
public static double CalculateDistance(this Location locationStart, Location locationEnd, DistanceUnits units) => Location.CalculateDistance(locationStart, locationEnd, units);
public static double CalculateDistance(this Location locationStart, double latitudeEnd, double longitudeEnd, DistanceUnits units) => Location.CalculateDistance(locationStart, latitudeEnd, longitudeEnd, units);