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 java.util.List;
  
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.api.DetailNode;
  import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
  
  /**
   * Presentation model for CodeSelector.
   */
  public class CodeSelectorPresentation {
  
      /** DetailAST or DetailNode node. */
      private final Object node;
      /** Mapping. */
      private final List<Integer> lines2position;
      /** Selection start position. */
      private int selectionStart;
      /** Selection end position. */
      private int selectionEnd;
  
      /**
       * Constructor.
       *
       * @param ast ast node.
       * @param lines2position positions of lines.
       * @noinspection AssignmentOrReturnOfFieldWithMutableType
       * @noinspectionreason AssignmentOrReturnOfFieldWithMutableType - mutability is
       *      expected in list of lines of code
       */
      public CodeSelectorPresentation(DetailAST ast, List<Integer> lines2position) {
          node = ast;
          this.lines2position = lines2position;
      }
  
      /**
       * Constructor.
       *
       * @param node DetailNode node.
       * @param lines2position list to map lines.
       * @noinspection AssignmentOrReturnOfFieldWithMutableType
       * @noinspectionreason AssignmentOrReturnOfFieldWithMutableType - mutability is expected
       *      in list of lines of code
       */
      public CodeSelectorPresentation(DetailNode node, List<Integer> lines2position) {
          this.node = node;
          this.lines2position = lines2position;
      }
  
      /**
       * Returns selection start position.
       *
       * @return selection start position.
       */
      public int getSelectionStart() {
          return selectionStart;
      }
  
      /**
       * Returns selection end position.
       *
       * @return selection end position.
       */
      public int getSelectionEnd() {
          return selectionEnd;
      }
  
      /**
       * Find start and end selection positions from AST line and Column.
       */
      public void findSelectionPositions() {
          if (node instanceof DetailAST) {
              findSelectionPositions((DetailAST) node);
          }
          else {
              findSelectionPositions((DetailNode) node);
          }
      }
  
      /**
       * Find start and end selection positions from AST line and Column.
       *
       * @param ast DetailAST node for which selection finds
       */
      private void findSelectionPositions(DetailAST ast) {
          selectionStart = lines2position.get(ast.getLineNo()) + ast.getColumnNo();
  
          if (ast.hasChildren() || !TokenUtil.getTokenName(ast.getType()).equals(ast.getText())) {
              selectionEnd = findLastPosition(ast);
          }
          else {
              selectionEnd = selectionStart;
          }
      }
  
      /**
       * Find start and end selection positions from DetailNode line and Column.
       *
       * @param detailNode DetailNode node for which selection finds
       */
      private void findSelectionPositions(DetailNode detailNode) {
          selectionStart = lines2position.get(detailNode.getLineNumber())
                              + detailNode.getColumnNumber();
  
          selectionEnd = findLastPosition(detailNode);
      }
  
      /**
       * Finds the last position of node without children.
       *
       * @param astNode DetailAST node.
       * @return Last position of node without children.
       */
      private int findLastPosition(final DetailAST astNode) {
          final int lastPosition;
          if (astNode.hasChildren()) {
              lastPosition = findLastPosition(astNode.getLastChild());
          }
          else {
              lastPosition = lines2position.get(astNode.getLineNo()) + astNode.getColumnNo()
                      + astNode.getText().length();
          }
          return lastPosition;
      }
  
      /**
       * Finds the last position of node without children.
       *
       * @param detailNode DetailNode node.
       * @return Last position of node without children.
       */
      private int findLastPosition(final DetailNode detailNode) {
          final int lastPosition;
          if (detailNode.getChildren().length == 0) {
              lastPosition = lines2position.get(detailNode.getLineNumber())
                      + detailNode.getColumnNumber() + detailNode.getText().length();
          }
          else {
              final DetailNode lastChild =
                      detailNode.getChildren()[detailNode.getChildren().length - 1];
              lastPosition = findLastPosition(lastChild);
          }
          return lastPosition;
      }
  
  }
  