1  // HTMLParser Library $Name: v1_6_20060319 $ - A java-based parser for HTML
  2  // http://sourceforge.org/projects/htmlparser
  3  // Copyright (C) 2004 Derrick Oswald
  4  //
  5  // Revision Control Information
  6  //
  7  // $Source: /cvsroot/htmlparser/htmlparser/src/org/htmlparser/sax/Locator.java,v $
  8  // $Author: derrickoswald $
  9  // $Date: 2004/07/14 01:58:02 $
 10  // $Revision: 1.1 $
 11  //
 12  // This library is free software; you can redistribute it and/or
 13  // modify it under the terms of the GNU Lesser General Public
 14  // License as published by the Free Software Foundation; either
 15  // version 2.1 of the License, or (at your option) any later version.
 16  //
 17  // This library is distributed in the hope that it will be useful,
 18  // but WITHOUT ANY WARRANTY; without even the implied warranty of
 19  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 20  // Lesser General Public License for more details.
 21  //
 22  // You should have received a copy of the GNU Lesser General Public
 23  // License along with this library; if not, write to the Free Software
 24  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 25  //
 26  
 27  package org.htmlparser.sax;
 28  
 29  import org.htmlparser.Parser;
 30  import org.htmlparser.lexer.Lexer;
 31  
 32  /**
 33   * Transforms character offsets into line and column in the HTML file.
 34   */
 35  public class Locator
 36      implements
 37          org.xml.sax.Locator
 38  {
 39      /**
 40       * Underlying parser object.
 41       */
 42      protected Parser mParser;
 43  
 44      /**
 45       * Creates a locator for the given parser.
 46       * @param parser The parser with the {@link org.htmlparser.lexer.Page Page} being accessed.
 47       */
 48      public Locator (Parser parser)
 49      {
 50          mParser = parser;
 51      }
 52      
 53      /**
 54       * Return the public identifier for the current document event.
 55       *
 56       * <p>The return value is the public identifier of the document
 57       * entity or of the external parsed entity in which the markup
 58       * triggering the event appears.</p>
 59       *
 60       * @return A string containing the public identifier, or
 61       *         null if none is available.
 62       * @see #getSystemId
 63       */
 64      public String getPublicId ()
 65      {
 66          return (null); // I assume this would be <title></title>
 67      }
 68      
 69      
 70      /**
 71       * Return the system identifier for the current document event.
 72       *
 73       * <p>The return value is the system identifier of the document
 74       * entity or of the external parsed entity in which the markup
 75       * triggering the event appears.</p>
 76       *
 77       * <p>If the system identifier is a URL, the parser must resolve it
 78       * fully before passing it to the application.  For example, a file
 79       * name must always be provided as a <em>file:...</em> URL, and other
 80       * kinds of relative URI are also resolved against their bases.</p>
 81       *
 82       * @return A string containing the system identifier, or null
 83       *         if none is available.
 84       * @see #getPublicId
 85       */
 86      public String getSystemId ()
 87      {
 88          return (mParser.getURL ());
 89      }
 90      
 91      
 92      /**
 93       * Return the line number where the current document event ends.
 94       * Lines are delimited by line ends, which are defined in
 95       * the XML specification.
 96       *
 97       * <p><strong>Warning:</strong> The return value from the method
 98       * is intended only as an approximation for the sake of diagnostics;
 99       * it is not intended to provide sufficient information
100       * to edit the character content of the original XML document.
101       * In some cases, these "line" numbers match what would be displayed
102       * as columns, and in others they may not match the source text
103       * due to internal entity expansion.  </p>
104       *
105       * <p>The return value is an approximation of the line number
106       * in the document entity or external parsed entity where the
107       * markup triggering the event appears.</p>
108       *
109       * <p>If possible, the SAX driver should provide the line position 
110       * of the first character after the text associated with the document 
111       * event.  The first line is line 1.</p>
112       *
113       * @return The line number, or -1 if none is available.
114       * @see #getColumnNumber
115       */
116      public int getLineNumber ()
117      {
118          Lexer lexer;
119          
120          lexer = mParser.getLexer ();
121          return (lexer.getPage ().row (lexer.getCursor ()));
122      }
123      
124      
125      /**
126       * Return the column number where the current document event ends.
127       * This is one-based number of Java <code>char</code> values since
128       * the last line end.
129       *
130       * <p><strong>Warning:</strong> The return value from the method
131       * is intended only as an approximation for the sake of diagnostics;
132       * it is not intended to provide sufficient information
133       * to edit the character content of the original XML document.
134       * For example, when lines contain combining character sequences, wide
135       * characters, surrogate pairs, or bi-directional text, the value may
136       * not correspond to the column in a text editor's display. </p>
137       *
138       * <p>The return value is an approximation of the column number
139       * in the document entity or external parsed entity where the
140       * markup triggering the event appears.</p>
141       *
142       * <p>If possible, the SAX driver should provide the line position 
143       * of the first character after the text associated with the document 
144       * event.  The first column in each line is column 1.</p>
145       *
146       * @return The column number, or -1 if none is available.
147       * @see #getLineNumber
148       */
149      public int getColumnNumber ()
150      {
151          Lexer lexer;
152          
153          lexer = mParser.getLexer ();
154          return (lexer.getPage ().column (lexer.getCursor ()));
155      }
156  }