1
2
3
4
5
6 package org.xml.sax;
7
8
9 /***
10 * Interface for associating a SAX event with a document location.
11 *
12 * <blockquote>
13 * <em>This module, both source code and documentation, is in the
14 * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
15 * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
16 * for further information.
17 * </blockquote>
18 *
19 * <p>If a SAX parser provides location information to the SAX
20 * application, it does so by implementing this interface and then
21 * passing an instance to the application using the content
22 * handler's {@link org.xml.sax.ContentHandler#setDocumentLocator
23 * setDocumentLocator} method. The application can use the
24 * object to obtain the location of any other SAX event
25 * in the XML source document.</p>
26 *
27 * <p>Note that the results returned by the object will be valid only
28 * during the scope of each callback method: the application
29 * will receive unpredictable results if it attempts to use the
30 * locator at any other time, or after parsing completes.</p>
31 *
32 * <p>SAX parsers are not required to supply a locator, but they are
33 * very strongly encouraged to do so. If the parser supplies a
34 * locator, it must do so before reporting any other document events.
35 * If no locator has been set by the time the application receives
36 * the {@link org.xml.sax.ContentHandler#startDocument startDocument}
37 * event, the application should assume that a locator is not
38 * available.</p>
39 *
40 * @since SAX 1.0
41 * @author David Megginson
42 * @version 2.0.1 (sax2r2)
43 * @see org.xml.sax.ContentHandler#setDocumentLocator
44 */
45 public interface Locator {
46
47
48 /***
49 * Return the public identifier for the current document event.
50 *
51 * <p>The return value is the public identifier of the document
52 * entity or of the external parsed entity in which the markup
53 * triggering the event appears.</p>
54 *
55 * @return A string containing the public identifier, or
56 * null if none is available.
57 * @see #getSystemId
58 */
59 public abstract String getPublicId ();
60
61
62 /***
63 * Return the system identifier for the current document event.
64 *
65 * <p>The return value is the system identifier of the document
66 * entity or of the external parsed entity in which the markup
67 * triggering the event appears.</p>
68 *
69 * <p>If the system identifier is a URL, the parser must resolve it
70 * fully before passing it to the application. For example, a file
71 * name must always be provided as a <em>file:...</em> URL, and other
72 * kinds of relative URI are also resolved against their bases.</p>
73 *
74 * @return A string containing the system identifier, or null
75 * if none is available.
76 * @see #getPublicId
77 */
78 public abstract String getSystemId ();
79
80
81 /***
82 * Return the line number where the current document event ends.
83 * Lines are delimited by line ends, which are defined in
84 * the XML specification.
85 *
86 * <p><strong>Warning:</strong> The return value from the method
87 * is intended only as an approximation for the sake of diagnostics;
88 * it is not intended to provide sufficient information
89 * to edit the character content of the original XML document.
90 * In some cases, these "line" numbers match what would be displayed
91 * as columns, and in others they may not match the source text
92 * due to internal entity expansion. </p>
93 *
94 * <p>The return value is an approximation of the line number
95 * in the document entity or external parsed entity where the
96 * markup triggering the event appears.</p>
97 *
98 * <p>If possible, the SAX driver should provide the line position
99 * of the first character after the text associated with the document
100 * event. The first line is line 1.</p>
101 *
102 * @return The line number, or -1 if none is available.
103 * @see #getColumnNumber
104 */
105 public abstract int getLineNumber ();
106
107
108 /***
109 * Return the column number where the current document event ends.
110 * This is one-based number of Java <code>char</code> values since
111 * the last line end.
112 *
113 * <p><strong>Warning:</strong> The return value from the method
114 * is intended only as an approximation for the sake of diagnostics;
115 * it is not intended to provide sufficient information
116 * to edit the character content of the original XML document.
117 * For example, when lines contain combining character sequences, wide
118 * characters, surrogate pairs, or bi-directional text, the value may
119 * not correspond to the column in a text editor's display. </p>
120 *
121 * <p>The return value is an approximation of the column number
122 * in the document entity or external parsed entity where the
123 * markup triggering the event appears.</p>
124 *
125 * <p>If possible, the SAX driver should provide the line position
126 * of the first character after the text associated with the document
127 * event. The first column in each line is column 1.</p>
128 *
129 * @return The column number, or -1 if none is available.
130 * @see #getLineNumber
131 */
132 public abstract int getColumnNumber ();
133
134 }
135
136