@Override
    public LegacyFilterConfig getConfig() {
        final LegacyFilterConfig config = super.getConfig();
        config.putList(CONFIG_KEY_USE_CURRENT_POS, Boolean.toString(useCurrentPosition));
        config.putList(CONFIG_KEY_COORD, coordinate == null ? "-" : GeopointFormatter.format(GeopointFormatter.Format.LAT_LON_DECMINUTE, coordinate));
        return config;
    }
Returns the coordinate which will effectively be used for calculation (either fixed-value or current position)
main/src/main/java/cgeo/geocaching/filters/core/DistanceGeocacheFilter.java