View Javadoc
1   /*
2    * Copyright (c) 2000, 2005, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  // SAX locator interface for document events.
27  // http://www.saxproject.org
28  // No warranty; no copyright -- use this as you will.
29  // $Id: Locator.java,v 1.2 2004/11/03 22:55:32 jsuttor Exp $
30  
31  package org.xml.sax;
32  
33  
34  /**
35   * Interface for associating a SAX event with a document location.
36   *
37   * <blockquote>
38   * <em>This module, both source code and documentation, is in the
39   * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
40   * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>;
41   * for further information.
42   * </blockquote>
43   *
44   * <p>If a SAX parser provides location information to the SAX
45   * application, it does so by implementing this interface and then
46   * passing an instance to the application using the content
47   * handler's {@link org.xml.sax.ContentHandler#setDocumentLocator
48   * setDocumentLocator} method.  The application can use the
49   * object to obtain the location of any other SAX event
50   * in the XML source document.</p>
51   *
52   * <p>Note that the results returned by the object will be valid only
53   * during the scope of each callback method: the application
54   * will receive unpredictable results if it attempts to use the
55   * locator at any other time, or after parsing completes.</p>
56   *
57   * <p>SAX parsers are not required to supply a locator, but they are
58   * very strongly encouraged to do so.  If the parser supplies a
59   * locator, it must do so before reporting any other document events.
60   * If no locator has been set by the time the application receives
61   * the {@link org.xml.sax.ContentHandler#startDocument startDocument}
62   * event, the application should assume that a locator is not
63   * available.</p>
64   *
65   * @since SAX 1.0
66   * @author David Megginson
67   * @see org.xml.sax.ContentHandler#setDocumentLocator
68   */
69  public interface Locator {
70  
71  
72      /**
73       * Return the public identifier for the current document event.
74       *
75       * <p>The return value is the public identifier of the document
76       * entity or of the external parsed entity in which the markup
77       * triggering the event appears.</p>
78       *
79       * @return A string containing the public identifier, or
80       *         null if none is available.
81       * @see #getSystemId
82       */
83      public abstract String getPublicId ();
84  
85  
86      /**
87       * Return the system identifier for the current document event.
88       *
89       * <p>The return value is the system identifier of the document
90       * entity or of the external parsed entity in which the markup
91       * triggering the event appears.</p>
92       *
93       * <p>If the system identifier is a URL, the parser must resolve it
94       * fully before passing it to the application.  For example, a file
95       * name must always be provided as a <em>file:...</em> URL, and other
96       * kinds of relative URI are also resolved against their bases.</p>
97       *
98       * @return A string containing the system identifier, or null
99       *         if none is available.
100      * @see #getPublicId
101      */
102     public abstract String getSystemId ();
103 
104 
105     /**
106      * Return the line number where the current document event ends.
107      * Lines are delimited by line ends, which are defined in
108      * the XML specification.
109      *
110      * <p><strong>Warning:</strong> The return value from the method
111      * is intended only as an approximation for the sake of diagnostics;
112      * it is not intended to provide sufficient information
113      * to edit the character content of the original XML document.
114      * In some cases, these "line" numbers match what would be displayed
115      * as columns, and in others they may not match the source text
116      * due to internal entity expansion.  </p>
117      *
118      * <p>The return value is an approximation of the line number
119      * in the document entity or external parsed entity where the
120      * markup triggering the event appears.</p>
121      *
122      * <p>If possible, the SAX driver should provide the line position
123      * of the first character after the text associated with the document
124      * event.  The first line is line 1.</p>
125      *
126      * @return The line number, or -1 if none is available.
127      * @see #getColumnNumber
128      */
129     public abstract int getLineNumber ();
130 
131 
132     /**
133      * Return the column number where the current document event ends.
134      * This is one-based number of Java <code>char</code> values since
135      * the last line end.
136      *
137      * <p><strong>Warning:</strong> The return value from the method
138      * is intended only as an approximation for the sake of diagnostics;
139      * it is not intended to provide sufficient information
140      * to edit the character content of the original XML document.
141      * For example, when lines contain combining character sequences, wide
142      * characters, surrogate pairs, or bi-directional text, the value may
143      * not correspond to the column in a text editor's display. </p>
144      *
145      * <p>The return value is an approximation of the column number
146      * in the document entity or external parsed entity where the
147      * markup triggering the event appears.</p>
148      *
149      * <p>If possible, the SAX driver should provide the line position
150      * of the first character after the text associated with the document
151      * event.  The first column in each line is column 1.</p>
152      *
153      * @return The column number, or -1 if none is available.
154      * @see #getLineNumber
155      */
156     public abstract int getColumnNumber ();
157 
158 }
159 
160 // end of Locator.java