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
31package 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 1.4, SAX 1.0
66 * @author David Megginson
67 * @see org.xml.sax.ContentHandler#setDocumentLocator
68 */
69public 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
161