001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2005, 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 2003-2005, by Object Refinery Limited and Contributors.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: PieDatasetHandler.java,v 1.3.2.1 2005/10/25 21:36:10 mungady Exp $
036     *
037     * Changes (from 21-Jun-2001)
038     * --------------------------
039     * 23-Jan-2003 : Version 1 (DG);
040     *
041     */
042    
043    package org.jfree.data.xml;
044    
045    import org.jfree.data.general.DefaultPieDataset;
046    import org.jfree.data.general.PieDataset;
047    import org.xml.sax.Attributes;
048    import org.xml.sax.SAXException;
049    import org.xml.sax.helpers.DefaultHandler;
050    
051    /**
052     * A SAX handler for reading a {@link PieDataset} from an XML file.
053     */
054    public class PieDatasetHandler extends RootHandler implements DatasetTags {
055    
056        /** The pie dataset under construction. */
057        private DefaultPieDataset dataset;
058    
059        /**
060         * Default constructor.
061         */
062        public PieDatasetHandler() {
063            this.dataset = null;
064        }
065    
066        /**
067         * Returns the dataset.
068         *
069         * @return The dataset.
070         */
071        public PieDataset getDataset() {
072            return this.dataset;
073        }
074    
075        /**
076         * Adds an item to the dataset under construction.
077         *
078         * @param key  the key.
079         * @param value  the value.
080         */
081        public void addItem(Comparable key, Number value) {
082            this.dataset.setValue(key, value);
083        }
084    
085        /**
086         * Starts an element.
087         *
088         * @param namespaceURI  the namespace.
089         * @param localName  the element name.
090         * @param qName  the element name.
091         * @param atts  the element attributes.
092         *
093         * @throws SAXException for errors.
094         */
095        public void startElement(String namespaceURI,
096                                 String localName,
097                                 String qName,
098                                 Attributes atts) throws SAXException {
099    
100            DefaultHandler current = getCurrentHandler();
101            if (current != this) {
102                current.startElement(namespaceURI, localName, qName, atts);
103            }
104            else if (qName.equals(PIEDATASET_TAG)) {
105                this.dataset = new DefaultPieDataset();
106            }
107            else if (qName.equals(ITEM_TAG)) {
108                ItemHandler subhandler = new ItemHandler(this, this);
109                getSubHandlers().push(subhandler);
110                subhandler.startElement(namespaceURI, localName, qName, atts);
111            }
112    
113        }
114    
115        /**
116         * The end of an element.
117         *
118         * @param namespaceURI  the namespace.
119         * @param localName  the element name.
120         * @param qName  the element name.
121         *
122         * @throws SAXException for errors.
123         */
124        public void endElement(String namespaceURI,
125                               String localName,
126                               String qName) throws SAXException {
127    
128            DefaultHandler current = getCurrentHandler();
129            if (current != this) {
130                current.endElement(namespaceURI, localName, qName);
131            }
132    
133        }
134    
135    }