private void setTrack(final String key, final IGeoItemSupplier route, final int unused1, final int unused2) {
        tracks.setRoute(key, route);
        resumeTrack(key, null == route);
        updateRouteTrackButtonVisibility();
    }
Repaint position overlay but only with a max frequency and if position or heading changes sufficiently.
main/src/main/java/cgeo/geocaching/maps/mapsforge/v6/NewMap.java