@Override
    public void setConfig(final LegacyFilterConfig config) {
        super.setConfig(config);
        useCurrentPosition = config.getFirstValue(CONFIG_KEY_USE_CURRENT_POS, false, BooleanUtils::toBoolean);
        coordinate = config.getFirstValue(CONFIG_KEY_COORD, null, s -> GeopointParser.parse(s, null));
    }
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