altoslib: Store common frequencies in library version-independent form

Serializable Objects in java are very specific to the class being
serialized. As we bump the name of the library on a regular basis to
note API/ABI issues, this mean a saved a Serializable object in
the preferences database will fail to load across library version
upgrades.

The saved tracker state and saved common frequencies were the only
objects saved in this form; this patch adds infrastructure for writing
objects in a version-independent form, and then adds support for
saving frequencies in that form.

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

1 files changed, 13 insertions, 0 deletions

diff --git a/altoslib/AltosFrequency.java b/altoslib/AltosFrequency.java
index ef46bd67..88997152 100644
--- a/altoslib/AltosFrequency.java
+++ b/altoslib/AltosFrequency.java
@@ -58,8 +58,21 @@ public class AltosFrequency implements Serializable {
 		return diff < 0.010;
 	}
 
+	public AltosHashSet hashSet() {
+		AltosHashSet	h = new AltosHashSet();
+
+		h.putDouble("frequency", frequency);
+		h.putString("description", description);
+		return h;
+	}
+
 	public AltosFrequency(double f, String d) {
 		frequency = f;
 		description = d;
 	}
+
+	public AltosFrequency(AltosHashSet h) {
+		frequency = h.getDouble("frequency", 0.0);
+		description = h.getString("description", "");
+	}
 }