public override void ViewWillAppear(bool animated)
{
base.ViewWillAppear(animated);
// Default to the region for North America
double minLatitude = 37.37 - (28.49 / 2);
double maxLatitude = 37.37 + (28.49 / 2);
double minLongitide = -96.24 - (31.025 / 2);
double maxLongitude = -96.24 + (31.025 / 2);
bool initialized = false;
foreach (var code in LogBook.GetVisitedAirports())
{
Airport airport = Airports.GetAirport(code, AirportCode.FAA);
if (airport == null)
{
continue;
}
if (!initialized)
{
minLongitide = maxLongitude = airport.Longitude;
minLatitude = maxLatitude = airport.Latitude;
initialized = true;
}
else
{
minLongitide = Math.Min(minLongitide, airport.Longitude);
maxLongitude = Math.Max(maxLongitude, airport.Longitude);
minLatitude = Math.Min(minLatitude, airport.Latitude);
maxLatitude = Math.Max(maxLatitude, airport.Latitude);
}
}
coordinates = new CLLocationCoordinate2D((minLatitude + maxLatitude) / 2, (minLongitide + maxLongitude) / 2);
double spanLongitude = Math.Abs(maxLongitude - minLongitide);
double spanLatitude = Math.Abs(maxLatitude - minLatitude);
if (initialized)
{
spanLongitude = Math.Max(spanLongitude, 1.0) * 1.25;
spanLatitude = Math.Max(spanLatitude, 1.0) * 1.25;
}
// Get the region for North America
var region = new MKCoordinateRegion(
coordinates, new MKCoordinateSpan(spanLatitude, spanLongitude)
);
mapView.SetRegion(region, animated);
}
IEnumerable <Airport> GetAirports(MKCoordinateRegion region)
{
if (visited)
{
foreach (var code in LogBook.GetVisitedAirports())
{
Airport airport = Airports.GetAirport(code, AirportCode.FAA);
if (airport != null)
{
yield return(airport);
}
}
}
else
{
foreach (var airport in Airports.GetAirports(region))
{
yield return(airport);
}
}
yield break;
}