private void notifySelection(@Nullable ListSelectionEvent event) {
    if (event != null) {
      PaletteItemsComponent sourceItemsComponent = (PaletteItemsComponent)event.getSource();
      for (int i = event.getFirstIndex(); i <= event.getLastIndex(); i++) {
        if (sourceItemsComponent.isSelectedIndex(i)) {
          for (PaletteItemsComponent itemsComponent : myItemsComponents) {
            if (itemsComponent != sourceItemsComponent) {
              itemsComponent.clearSelection();
            }
          }
          PaletteItem paletteItem = (PaletteItem)sourceItemsComponent.getSelectedValue();
          if (paletteItem != null && !paletteItem.isEnabled()) {
            sourceItemsComponent.clearSelection();
          }
          break;
        }
      }
    }
    if (myDesigner != null) {
      myDesigner.activatePaletteItem(getActiveItem());
    }
  }
private void notifySelection(@Nullable ListSelectionEvent event)