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 * PieDatasetHandler.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
041package org.jfree.data.xml;
042
043import org.jfree.data.general.DefaultPieDataset;
044import org.jfree.data.general.PieDataset;
045import org.xml.sax.Attributes;
046import org.xml.sax.SAXException;
047import org.xml.sax.helpers.DefaultHandler;
048
049/**
050 * A SAX handler for reading a {@link PieDataset} from an XML file.
051 */
052public class PieDatasetHandler extends RootHandler implements DatasetTags {
053
054    /** The pie dataset under construction. */
055    private DefaultPieDataset dataset;
056
057    /**
058     * Default constructor.
059     */
060    public PieDatasetHandler() {
061        this.dataset = null;
062    }
063
064    /**
065     * Returns the dataset.
066     *
067     * @return The dataset.
068     */
069    public PieDataset getDataset() {
070        return this.dataset;
071    }
072
073    /**
074     * Adds an item to the dataset under construction.
075     *
076     * @param key  the key.
077     * @param value  the value.
078     */
079    public void addItem(Comparable key, Number value) {
080        this.dataset.setValue(key, value);
081    }
082
083    /**
084     * Starts an element.
085     *
086     * @param namespaceURI  the namespace.
087     * @param localName  the element name.
088     * @param qName  the element name.
089     * @param atts  the element attributes.
090     *
091     * @throws SAXException for errors.
092     */
093    public void startElement(String namespaceURI,
094                             String localName,
095                             String qName,
096                             Attributes atts) throws SAXException {
097
098        DefaultHandler current = getCurrentHandler();
099        if (current != this) {
100            current.startElement(namespaceURI, localName, qName, atts);
101        }
102        else if (qName.equals(PIEDATASET_TAG)) {
103            this.dataset = new DefaultPieDataset();
104        }
105        else if (qName.equals(ITEM_TAG)) {
106            ItemHandler subhandler = new ItemHandler(this, this);
107            getSubHandlers().push(subhandler);
108            subhandler.startElement(namespaceURI, localName, qName, atts);
109        }
110
111    }
112
113    /**
114     * The end of an element.
115     *
116     * @param namespaceURI  the namespace.
117     * @param localName  the element name.
118     * @param qName  the element name.
119     *
120     * @throws SAXException for errors.
121     */
122    public void endElement(String namespaceURI,
123                           String localName,
124                           String qName) throws SAXException {
125
126        DefaultHandler current = getCurrentHandler();
127        if (current != this) {
128            current.endElement(namespaceURI, localName, qName);
129        }
130
131    }
132
133}