001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
006 *
007 * Project Info: http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022 * USA.
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * ----------------
028 * ItemHandler.java
029 * ----------------
030 * (C) Copyright 2003-2008, by Object Refinery Limited and Contributors.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes
036 * -------
037 * 23-Jan-2003 : Version 1 (DG);
038 *
039 */
040
041 package org.jfree.data.xml;
042
043 import org.xml.sax.Attributes;
044 import org.xml.sax.SAXException;
045 import org.xml.sax.helpers.DefaultHandler;
046
047 /**
048 * A handler for reading key-value items.
049 */
050 public class ItemHandler extends DefaultHandler implements DatasetTags {
051
052 /** The root handler. */
053 private RootHandler root;
054
055 /** The parent handler (can be the same as root, but not always). */
056 private DefaultHandler parent;
057
058 /** The key. */
059 private Comparable key;
060
061 /** The value. */
062 private Number value;
063
064 /**
065 * Creates a new item handler.
066 *
067 * @param root the root handler.
068 * @param parent the parent handler.
069 */
070 public ItemHandler(RootHandler root, DefaultHandler parent) {
071 this.root = root;
072 this.parent = parent;
073 this.key = null;
074 this.value = null;
075 }
076
077 /**
078 * Returns the key that has been read by the handler, or <code>null</code>.
079 *
080 * @return The key.
081 */
082 public Comparable getKey() {
083 return this.key;
084 }
085
086 /**
087 * Sets the key.
088 *
089 * @param key the key.
090 */
091 public void setKey(Comparable key) {
092 this.key = key;
093 }
094
095 /**
096 * Returns the key that has been read by the handler, or <code>null</code>.
097 *
098 * @return The value.
099 */
100 public Number getValue() {
101 return this.value;
102 }
103
104 /**
105 * Sets the value.
106 *
107 * @param value the value.
108 */
109 public void setValue(Number value) {
110 this.value = value;
111 }
112
113 /**
114 * The start of an element.
115 *
116 * @param namespaceURI the namespace.
117 * @param localName the element name.
118 * @param qName the element name.
119 * @param atts the attributes.
120 *
121 * @throws SAXException for errors.
122 */
123 public void startElement(String namespaceURI,
124 String localName,
125 String qName,
126 Attributes atts) throws SAXException {
127
128 if (qName.equals(ITEM_TAG)) {
129 KeyHandler subhandler = new KeyHandler(this.root, this);
130 this.root.pushSubHandler(subhandler);
131 }
132 else if (qName.equals(VALUE_TAG)) {
133 ValueHandler subhandler = new ValueHandler(this.root, this);
134 this.root.pushSubHandler(subhandler);
135 }
136 else {
137 throw new SAXException(
138 "Expected <Item> or <Value>...found " + qName
139 );
140 }
141
142 }
143
144 /**
145 * The end of an element.
146 *
147 * @param namespaceURI the namespace.
148 * @param localName the element name.
149 * @param qName the element name.
150 */
151 public void endElement(String namespaceURI,
152 String localName,
153 String qName) {
154
155 if (this.parent instanceof PieDatasetHandler) {
156 PieDatasetHandler handler = (PieDatasetHandler) this.parent;
157 handler.addItem(this.key, this.value);
158 this.root.popSubHandler();
159 }
160 else if (this.parent instanceof CategorySeriesHandler) {
161 CategorySeriesHandler handler = (CategorySeriesHandler) this.parent;
162 handler.addItem(this.key, this.value);
163 this.root.popSubHandler();
164 }
165
166 }
167
168 }