svoid dm_onShow(final Runnable r) {
  final DynModule m = dm_current_mandatory();
  dm_ownResource(vmBus_onMessage('moduleStatusChange, new VF2<O, O[]>() {
    bool visible;
    
    public void get(O module, O[] params) {
      if (module == m && visible != dm_visible(m)) {
        if (visible = !visible) {
          temp m.enter();
          callF(r);
        }
        print("visibility: " + visible);
      }
    }
  }));
}