001// SAX locator interface for document events. 002// http://www.saxproject.org 003// No warranty; no copyright -- use this as you will. 004// $Id: Locator.java,v 1.1 2004/12/23 22:38:42 mark Exp $ 005 006package org.xml.sax; 007 008 009/** 010 * Interface for associating a SAX event with a document location. 011 * 012 * <blockquote> 013 * <em>This module, both source code and documentation, is in the 014 * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em> 015 * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a> 016 * for further information. 017 * </blockquote> 018 * 019 * <p>If a SAX parser provides location information to the SAX 020 * application, it does so by implementing this interface and then 021 * passing an instance to the application using the content 022 * handler's {@link org.xml.sax.ContentHandler#setDocumentLocator 023 * setDocumentLocator} method. The application can use the 024 * object to obtain the location of any other SAX event 025 * in the XML source document.</p> 026 * 027 * <p>Note that the results returned by the object will be valid only 028 * during the scope of each callback method: the application 029 * will receive unpredictable results if it attempts to use the 030 * locator at any other time, or after parsing completes.</p> 031 * 032 * <p>SAX parsers are not required to supply a locator, but they are 033 * very strongly encouraged to do so. If the parser supplies a 034 * locator, it must do so before reporting any other document events. 035 * If no locator has been set by the time the application receives 036 * the {@link org.xml.sax.ContentHandler#startDocument startDocument} 037 * event, the application should assume that a locator is not 038 * available.</p> 039 * 040 * @since SAX 1.0 041 * @author David Megginson 042 * @version 2.0.1 (sax2r2) 043 * @see org.xml.sax.ContentHandler#setDocumentLocator 044 */ 045public interface Locator { 046 047 048 /** 049 * Return the public identifier for the current document event. 050 * 051 * <p>The return value is the public identifier of the document 052 * entity or of the external parsed entity in which the markup 053 * triggering the event appears.</p> 054 * 055 * @return A string containing the public identifier, or 056 * null if none is available. 057 * @see #getSystemId 058 */ 059 public abstract String getPublicId (); 060 061 062 /** 063 * Return the system identifier for the current document event. 064 * 065 * <p>The return value is the system identifier of the document 066 * entity or of the external parsed entity in which the markup 067 * triggering the event appears.</p> 068 * 069 * <p>If the system identifier is a URL, the parser must resolve it 070 * fully before passing it to the application. For example, a file 071 * name must always be provided as a <em>file:...</em> URL, and other 072 * kinds of relative URI are also resolved against their bases.</p> 073 * 074 * @return A string containing the system identifier, or null 075 * if none is available. 076 * @see #getPublicId 077 */ 078 public abstract String getSystemId (); 079 080 081 /** 082 * Return the line number where the current document event ends. 083 * Lines are delimited by line ends, which are defined in 084 * the XML specification. 085 * 086 * <p><strong>Warning:</strong> The return value from the method 087 * is intended only as an approximation for the sake of diagnostics; 088 * it is not intended to provide sufficient information 089 * to edit the character content of the original XML document. 090 * In some cases, these "line" numbers match what would be displayed 091 * as columns, and in others they may not match the source text 092 * due to internal entity expansion. </p> 093 * 094 * <p>The return value is an approximation of the line number 095 * in the document entity or external parsed entity where the 096 * markup triggering the event appears.</p> 097 * 098 * <p>If possible, the SAX driver should provide the line position 099 * 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// end of Locator.java