@Override
  protected JComponent createCenterPanel() {
    final JPanel p = ToolbarDecorator.createDecorator(myVariableTable)
      .setAddAction(new AnActionButtonRunnable() {
        @Override
        public void run(AnActionButton button) {
          stopVarEditing();
          myVariableTableModel.addVariable();
          myNamespaceTable.editCellAt(myVariableTableModel.getRowCount() - 1, 0);
        }
      }).setRemoveAction(new AnActionButtonRunnable() {
        @Override
        public void run(AnActionButton button) {
          myVariableTableModel.removeVariable(myVariableTable.getSelectedRow());
        }
      }).disableUpDownActions().createPanel();
    UIUtil.addBorder(p, IdeBorderFactory.createTitledBorder(XPathBundle.message("border.title.variables"), false));

    final JPanel n = ToolbarDecorator.createDecorator(myNamespaceTable)
      .setAddAction(myContextProvider.getContextElement() != null ? null : new AnActionButtonRunnable() {
        @Override
        public void run(AnActionButton button) {
          final ExternalResourceManager erm = ExternalResourceManager.getInstance();
          final List<String> allURIs = new ArrayList<>(Arrays.asList(erm.getResourceUrls(null, true)));
          final Collection<Namespace> namespaces = myNamespaceTableModel.getNamespaces();
          for (Namespace namespace : namespaces) {
            allURIs.remove(namespace.getUri());
          }
          Collections.sort(allURIs);

          final DataContext dataContext = DataManager.getInstance().getDataContext(myNamespaceTable);
          final Project project = CommonDataKeys.PROJECT.getData(dataContext);
          final AddNamespaceDialog dlg = new AddNamespaceDialog(project, myUnresolvedPrefixes, allURIs, AddNamespaceDialog.Mode.EDITABLE);
          if (dlg.showAndGet()) {
            myNamespaceTableModel.addNamespace(new Namespace(dlg.getPrefix(), dlg.getURI()));
          }
        }
      }).setRemoveAction(
        myContextProvider.getContextElement() != null ? null : new AnActionButtonRunnable() {
          @Override
          public void run(AnActionButton button) {
            myNamespaceTableModel.removeNamespace(myNamespaceTable.getSelectedRow());
          }
        }).disableUpDownActions().createPanel();
    UIUtil.addBorder(n, IdeBorderFactory.createTitledBorder(XPathBundle.message("border.title.namespaces"), false));

    mySplitter = new JBSplitter(true, getDimensionServiceKey(), 400 / 1000f);
    mySplitter.setHonorComponentsMinimumSize(true);
    mySplitter.setFirstComponent(n);
    mySplitter.setSecondComponent(p);

    return mySplitter;
  }
@Override
  protected JComponent createCenterPanel()