private WaypointType getSelectedWaypointType() {
        final WaypointType selectedType = waypointType.get();
        return selectedType != null ? selectedType : waypoint.getWaypointType();
    }
Save the current state of the calculator such that it can be restored after screen rotation (or similar)
main/src/main/java/cgeo/geocaching/EditWaypointActivity.java