Class Geofence

CodenameOne/src/com/codename1/location/Geofence.java:80–231

///
/// - GeofenceListener
public class Geofence {

    private final String id;

    // Location of the geofence
    private final Location loc;

    // radius in metres.
    private final int radius;

    // Expiration in milliseconds .  Duration, not timestamp.  -1L to never expire.
    private final long expiration;

    /// Constructor
    ///
    /// #### Parameters
    ///
    /// - `id`: unique identifier
    ///
    /// - `loc`: the center location of this Geofence
    ///
    /// - `radius`: @param radius     the radius in meters. Note that the actual radius will vary
    /// on an actual device depending on the hardware and OS.  Typical android and iOS devices
    /// have a minimum radius of 100m.
    ///
    /// - `expiration`: the expiration time in milliseconds.  Note that this is a duration, not a timestamp.  Use -1 to never expire.
    public Geofence(String id, Location loc, int radius, long expiration) {
        this.id = id;
        this.loc = loc;
        this.radius = radius;
        this.expiration = expiration;
    }

    /// Creates a comparator for sorting Geofences from the current Geofence.
    public static Comparator<Geofence> createDistanceComparator(final Geofence refRegion) {
        return new Comparator<Geofence>() {

            @Override
            public int compare(Geofence o1, Geofence o2) {
                double d1 = refRegion.getDistanceTo(o1);
                double d2 = refRegion.getDistanceTo(o2);
                return d1 < d2 ? -1 : d2 < d1 ? 1 : 0;
            }

        };
    }

    /// Creates a comparator for sorting Geofences from the given reference point.
    public static Comparator<Geofence> createDistanceComparator(final Location refPoint) {
        return new Comparator<Geofence>() {

            @Override
            public int compare(Geofence o1, Geofence o2) {
                double d1 = Math.max(0, refPoint.getDistanceTo(o1.getLoc()) - o1.getRadius());
                double d2 = Math.max(0, refPoint.getDistanceTo(o2.getLoc()) - o2.getRadius());
                return d1 < d2 ? -1 : d2 < d1 ? 1 : 0;
            }