code: ///////////////////////////////////////////////////////////////////////////////////////////////
  // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
  // Copyright (C) 2001-2023 the original author or authors.
  //
  // This library is free software; you can redistribute it and/or
  // modify it under the terms of the GNU Lesser General Public
  // License as published by the Free Software Foundation; either
  // version 2.1 of the License, or (at your option) any later version.
  //
  // This library is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  ///////////////////////////////////////////////////////////////////////////////////////////////
  
  package com.puppycrawl.tools.checkstyle.gui;
  
  import javax.swing.ListSelectionModel;
  import javax.swing.tree.DefaultTreeSelectionModel;
  import javax.swing.tree.TreePath;
  
  /**
   * ListToTreeSelectionModelWrapper extends DefaultTreeSelectionModel
   * to listen for changes in the ListSelectionModel it maintains. Once
   * a change in the ListSelectionModel happens, the paths are updated
   * in the DefaultTreeSelectionModel.
   *
   */
  class ListToTreeSelectionModelWrapper extends DefaultTreeSelectionModel {
  
      /** A unique serial version identifier. */
      private static final long serialVersionUID = 2267930983939339510L;
      /** TreeTable to perform updates on. */
      private final TreeTable treeTable;
      /** Set to true when we are updating the ListSelectionModel. */
      private boolean updatingListSelectionModel;
  
      /**
       * Constructor to initialise treeTable.
       *
       * @param jTreeTable TreeTable to perform updates on.
       */
      /* package */ ListToTreeSelectionModelWrapper(TreeTable jTreeTable) {
          treeTable = jTreeTable;
          getListSelectionModel().addListSelectionListener(event -> {
              updateSelectedPathsFromSelectedRows();
          });
      }
  
      /**
       * Returns the list selection model. ListToTreeSelectionModelWrapper
       * listens for changes to this model and updates the selected paths
       * accordingly.
       *
       * @return the list selection model
       */
      protected final ListSelectionModel getListSelectionModel() {
          return listSelectionModel;
      }
  
      /**
       * This is overridden to set {@code updatingListSelectionModel}
       * and message super. This is the only place DefaultTreeSelectionModel
       * alters the ListSelectionModel.
       */
      @Override
      public void resetRowSelection() {
          if (!updatingListSelectionModel) {
              updatingListSelectionModel = true;
              try {
                  super.resetRowSelection();
              }
              finally {
                  updatingListSelectionModel = false;
              }
          }
          // Notice how we don't message super if
          // updatingListSelectionModel is true. If
          // updatingListSelectionModel is true, it implies the
          // ListSelectionModel has already been updated and the
          // paths are the only thing that needs to be updated.
      }
  
      /**
       * If {@code updatingListSelectionModel} is false, this will
       * reset the selected paths from the selected rows in the list
       * selection model.
       */
      private void updateSelectedPathsFromSelectedRows() {
          if (!updatingListSelectionModel) {
              updatingListSelectionModel = true;
              try {
                  // This is way expensive, ListSelectionModel needs an
                  // enumerator for iterating.
                  final int min = listSelectionModel.getMinSelectionIndex();
                  final int max = listSelectionModel.getMaxSelectionIndex();
  
                  clearSelection();
                  if (min != -1 && max != -1) {
                      for (int counter = min; counter <= max; counter++) {
                          updateSelectedPathIfRowIsSelected(counter);
                      }
                  }
              }
              finally {
                  updatingListSelectionModel = false;
              }
          }
      }
  
      /**
       * If the row at given index is selected, selected paths are updated.
       *
       * @param counter number of row.
       */
      private void updateSelectedPathIfRowIsSelected(int counter) {
          if (listSelectionModel.isSelectedIndex(counter)) {
              final TreePath selPath = treeTable.getTree().getPathForRow(counter);
  
              if (selPath != null) {
                  addSelectionPath(selPath);
              }
          }
      }
  
  }
  