private void resumeTrack(final String key, final boolean preventReloading) {
        final Tracks tracks = mapActivity.getTracks();
        if (null == tracks && !preventReloading) {
            mapActivity.getRouteTrackUtils().reloadTrack(tracks.getTrackfile(key), this::setTrack);
        } else if (null != tracks && null != overlayPositionAndScale && overlayPositionAndScale instanceof GooglePositionAndHistory) {
            ((GooglePositionAndHistory) overlayPositionAndScale).updateRoute(key, tracks.getRoute(key), tracks.getColor(key), tracks.getWidth(key));
        }
    }
Set the zoom of the map. The zoom is restricted to a certain minimum in case of live map.
main/src/main/java/cgeo/geocaching/maps/CGeoMap.java