code: @Override
      public void notifyLayerChanged(FeatureProvider provider,
                                     Integer layerRefreshOld,
                                     Integer layerRefreshNew,
                                     Integer layerDisplayOld,
                                     Integer layerDisplayNew)
      {
          if (provider.hasFeature(Displayable.class))
          {
              final Displayable displayable = provider.getFeature(Displayable.class);
              getLayer(layerDisplayOld).remove(displayable);
              getLayer(layerDisplayNew).add(displayable);
              indexs.add(layerDisplayNew);
          }
      }
docs: /*
  LayerableListener