altoslib/altosuilib: Fix equals methods, add hashCode

Whenever we use a class as a HashMap key, that class needs to override
the equals(Object) and hashCode() methods. Otherwise, the hash table
won't work right.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/altoslib/AltosLatLon.java b/altoslib/AltosLatLon.java
index dc606ccb..1bcf6fd8 100644
--- a/altoslib/AltosLatLon.java
+++ b/altoslib/AltosLatLon.java
@@ -21,9 +21,17 @@ public class AltosLatLon {
 	public double	lat;
 	public double	lon;
 
-	public boolean equals(AltosLatLon other) {
-		if (other == null)
+	public int hashCode() {
+		return new Double(lat).hashCode() ^ new Double(lon).hashCode();
+	}
+
+	public boolean equals(Object o) {
+		if (o == null)
 			return false;
+		if (!(o instanceof AltosLatLon))
+			return false;
+
+		AltosLatLon other = (AltosLatLon) o;
 		return lat == other.lat && lon == other.lon;
 	}