001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * ----------------------
028 * PieDatasetHandler.java
029 * ----------------------
030 * (C) Copyright 2003-present, by David Gilbert and Contributors.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.data.xml;
038
039import org.jfree.data.general.DefaultPieDataset;
040import org.jfree.data.general.PieDataset;
041import org.xml.sax.Attributes;
042import org.xml.sax.SAXException;
043import org.xml.sax.helpers.DefaultHandler;
044
045/**
046 * A SAX handler for reading a {@link PieDataset} from an XML file.
047 */
048public class PieDatasetHandler extends RootHandler implements DatasetTags {
049
050    /** The pie dataset under construction. */
051    private DefaultPieDataset dataset;
052
053    /**
054     * Default constructor.
055     */
056    public PieDatasetHandler() {
057        this.dataset = null;
058    }
059
060    /**
061     * Returns the dataset.
062     *
063     * @return The dataset.
064     */
065    public PieDataset getDataset() {
066        return this.dataset;
067    }
068
069    /**
070     * Adds an item to the dataset under construction.
071     *
072     * @param key  the key.
073     * @param value  the value.
074     */
075    public void addItem(Comparable key, Number value) {
076        this.dataset.setValue(key, value);
077    }
078
079    /**
080     * Starts an element.
081     *
082     * @param namespaceURI  the namespace.
083     * @param localName  the element name.
084     * @param qName  the element name.
085     * @param atts  the element attributes.
086     *
087     * @throws SAXException for errors.
088     */
089    @Override
090    public void startElement(String namespaceURI,
091                             String localName,
092                             String qName,
093                             Attributes atts) throws SAXException {
094
095        DefaultHandler current = getCurrentHandler();
096        if (current != this) {
097            current.startElement(namespaceURI, localName, qName, atts);
098        }
099        else if (qName.equals(PIEDATASET_TAG)) {
100            this.dataset = new DefaultPieDataset();
101        }
102        else if (qName.equals(ITEM_TAG)) {
103            ItemHandler subhandler = new ItemHandler(this, this);
104            getSubHandlers().push(subhandler);
105            subhandler.startElement(namespaceURI, localName, qName, atts);
106        }
107
108    }
109
110    /**
111     * The end of an element.
112     *
113     * @param namespaceURI  the namespace.
114     * @param localName  the element name.
115     * @param qName  the element name.
116     *
117     * @throws SAXException for errors.
118     */
119    @Override
120    public void endElement(String namespaceURI,
121                           String localName,
122                           String qName) throws SAXException {
123
124        DefaultHandler current = getCurrentHandler();
125        if (current != this) {
126            current.endElement(namespaceURI, localName, qName);
127        }
128
129    }
130
131}