@NonNull
    public Geopoint getEffectiveCoordinate() {
        return (useCurrentPosition || coordinate == null) ?
                LocationDataProvider.getInstance().currentGeo().getCoords() : coordinate;
    }
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