context: using System;
  using System.Collections;
  using System.util.collections;
  using System.util;
  using iTextSharp.text;
  
  /*
   * $Id: PdfPageLabels.cs,v 1.3 2007/02/09 18:38:48 psoares33 Exp $
   * $Name:  $
   *
   * Copyright 2001, 2002 Paulo Soares
   *
   * The contents of this file are subject to the Mozilla Public License Version 1.1
   * (the "License"); you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at http://www.mozilla.org/MPL/
   *
   * Software distributed under the License is distributed on an "AS IS" basis,
   * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
   * for the specific language governing rights and limitations under the License.
   *
   * The Original Code is 'iText, a free JAVA-PDF library'.
   *
   * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
   * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
   * All Rights Reserved.
   * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
   * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
   *
   * Contributor(s): all the names of the contributors are added in the source code
   * where applicable.
   *
   * Alternatively, the contents of this file may be used under the terms of the
   * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
   * provisions of LGPL are applicable instead of those above.  If you wish to
   * allow use of your version of this file only under the terms of the LGPL
   * License and not to allow others to use your version of this file under
   * the MPL, indicate your decision by deleting the provisions above and
   * replace them with the notice and other provisions required by the LGPL.
   * If you do not delete the provisions above, a recipient may use your version
   * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the MPL as stated above or under the terms of the GNU
   * Library General Public License as published by the Free Software Foundation;
   * either version 2 of the License, or 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 Library general Public License for more
   * details.
   *
   * If you didn't download this code from the following link, you should check if
   * you aren't using an obsolete version:
   * http://www.lowagie.com/iText/
   */
  
  namespace iTextSharp.text.pdf {
  
      /** Page labels are used to identify each
       * page visually on the screen or in print.
       * @author  Paulo Soares (psoares@consiste.pt)
       */
      public class PdfPageLabels : IComparer {
  
          /** Logical pages will have the form 1,2,3,...
           */    
          public const int DECIMAL_ARABIC_NUMERALS = 0;
          /** Logical pages will have the form I,II,III,IV,...
           */    
          public const int UPPERCASE_ROMAN_NUMERALS = 1;
          /** Logical pages will have the form i,ii,iii,iv,...
           */    
          public const int LOWERCASE_ROMAN_NUMERALS = 2;
          /** Logical pages will have the form of uppercase letters
           * (A to Z for the first 26 pages, AA to ZZ for the next 26, and so on)
           */    
          public const int UPPERCASE_LETTERS = 3;
          /** Logical pages will have the form of uppercase letters
           * (a to z for the first 26 pages, aa to zz for the next 26, and so on)
           */    
          public const int LOWERCASE_LETTERS = 4;
          /** No logical page numbers are generated but fixed text may
           * still exist
           */    
          public const int EMPTY = 5;
          /** Dictionary values to set the logical page styles
           */    
          internal static PdfName[] numberingStyle = {PdfName.D, PdfName.R,
                      new PdfName("r"), PdfName.A, new PdfName("a")};
          /** The sequence of logical pages. Will contain at least a value for page 1
           */    
          internal k_Tree map;
      
          /** Creates a new PdfPageLabel with a default logical page 1
           */
          public PdfPageLabels() {
              map = new k_Tree(false, this);
              AddPageLabel(1, DECIMAL_ARABIC_NUMERALS, null, 1);
          }
  
          /** Compares two <CODE>int</CODE>.
           * @param obj the first <CODE>int</CODE>
           * @param obj1 the second <CODE>int</CODE>
           * @return a negative int, zero, or a positive int as the first argument is less than, equal to, or greater than the second
           */    
          public int Compare(Object obj, Object obj1) {
              int v1 = (int)obj;
              int v2 = (int)obj1;
              if (v1 < v2)
                  return -1;
              if (v1 == v2)
                  return 0;
              return 1;
          }
      
          /** Not used
           * @param obj not used
           * @return always <CODE>true</CODE>
           */    
          public new bool Equals(Object obj) {
              return true;
          }
      
          /** Adds or replaces a page label.
           * @param page the real page to start the numbering. First page is 1
           * @param numberStyle the numbering style such as LOWERCASE_ROMAN_NUMERALS
           * @param text the text to prefix the number. Can be <CODE>null</CODE> or empty
           * @param firstPage the first logical page number
           */    
          public void AddPageLabel(int page, int numberStyle, string text, int firstPage) {
              if (page < 1 || firstPage < 1)
                  throw new ArgumentException("In a page label the page numbers must be greater or equal to 1.");
              PdfName pdfName = null;
              if (numberStyle >= 0 && numberStyle < numberingStyle.Length)
                  pdfName = numberingStyle[numberStyle];
              int iPage = page;
              Object obj = new Object[]{iPage, pdfName, text, firstPage};
              map[iPage] = obj;
          }
  
          /** Adds or replaces a page label. The first logical page has the default
           * of 1.
           * @param page the real page to start the numbering. First page is 1
           * @param numberStyle the numbering style such as LOWERCASE_ROMAN_NUMERALS
           * @param text the text to prefix the number. Can be <CODE>null</CODE> or empty
           */    
          public void AddPageLabel(int page, int numberStyle, string text) {
              AddPageLabel(page, numberStyle, text, 1);
          }
      
          /** Adds or replaces a page label. There is no text prefix and the first
           * logical page has the default of 1.
           * @param page the real page to start the numbering. First page is 1
           * @param numberStyle the numbering style such as LOWERCASE_ROMAN_NUMERALS
           */    
          public void AddPageLabel(int page, int numberStyle) {
              AddPageLabel(page, numberStyle, null, 1);
          }
      
          /** Removes a page label. The first page lagel can not be removed, only changed.
           * @param page the real page to remove
           */    
          public void RemovePageLabel(int page) {
              if (page <= 1)
                  return;
              map.Remove(page);
          }
  
          /** Gets the page label dictionary to insert into the document.
           * @return the page label dictionary
           */    
          internal PdfDictionary Dictionary {
              get {
                  PdfDictionary dic = new PdfDictionary();
                  PdfArray array = new PdfArray();
                  foreach (object[] obj in map.Values) {
                      PdfDictionary subDic = new PdfDictionary();
                      PdfName pName = (PdfName)obj[1];
                      if (pName != null)
                          subDic.Put(PdfName.S, pName);
                      string text = (string)obj[2];
                      if (text != null)
                          subDic.Put(PdfName.P, new PdfString(text, PdfObject.TEXT_UNICODE));
                      int st = (int)obj[3];
                      if (st != 1)
                          subDic.Put(PdfName.ST, new PdfNumber(st));
                      array.Add(new PdfNumber((int)obj[0] - 1));
                      array.Add(subDic);
                  }
                  dic.Put(PdfName.NUMS, array);
                  return dic;
              }
          }
  
          /**
          * Retrieves the page labels from a PDF as an array of String objects.
          * @param reader a PdfReader object that has the page labels you want to retrieve
          * @return  a String array
          */
          public static String[] GetPageLabels(PdfReader reader) {
              
              int n = reader.NumberOfPages;
              String[] labelstrings = new String[n];
              
              PdfDictionary dict = reader.Catalog;
              PdfDictionary labels = (PdfDictionary)PdfReader.GetPdfObject((PdfObject)dict.Get(PdfName.PAGELABELS));
              PdfArray numbers = (PdfArray)PdfReader.GetPdfObject((PdfObject)labels.Get(PdfName.NUMS));
              
              PdfNumber pageIndex;
              PdfDictionary pageLabel;
              Hashtable numberTree = new Hashtable();
              for (ListIterator i = numbers.GetListIterator(); i.HasNext(); ) {
                  pageIndex = (PdfNumber)i.Next();
                  pageLabel = (PdfDictionary) PdfReader.GetPdfObject((PdfObject)i.Next());
                  numberTree[pageIndex.IntValue] = pageLabel;
              }
              
              int pagecount = 1;
              String prefix = "";
              char type = 'D';
              for (int i = 0; i < n; i++) {
                  if (numberTree.ContainsKey(i)) {
                      PdfDictionary d = (PdfDictionary)numberTree[i];
                      if (d.Contains(PdfName.ST)) {
                          pagecount = ((PdfNumber)d.Get(PdfName.ST)).IntValue;
                      }
                      else {
                          pagecount = 1;
                      }
                      if (d.Contains(PdfName.P)) {
                          prefix = ((PdfString)d.Get(PdfName.P)).ToString();
                      }
                      if (d.Contains(PdfName.S)) {
                          type = ((PdfName)d.Get(PdfName.S)).ToString()[1];
                      }
                  }
                  switch (type) {
                  default:
                      labelstrings[i] = prefix + pagecount;
                      break;
                  case 'R':
                      labelstrings[i] = prefix + RomanList.ToRomanUpperCase(pagecount);
                      break;
                  case 'r':
                      labelstrings[i] = prefix + RomanList.ToRomanLowerCase(pagecount);
                      break;
                  case 'A':
                      labelstrings[i] = prefix + List.GetUpperCaseLetter(pagecount);
                      break;
                  case 'a':
  
gt:                     labelstrings[i] = prefix + List.GetLowerCaseLetter(pagecount);