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 * CategoryDatasetHandler.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.category.CategoryDataset;
044import org.jfree.data.category.DefaultCategoryDataset;
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 CategoryDataset} from an XML file.
051 */
052public class CategoryDatasetHandler extends RootHandler implements DatasetTags {
053
054    /** The dataset under construction. */
055    private DefaultCategoryDataset dataset;
056
057    /**
058     * Creates a new handler.
059     */
060    public CategoryDatasetHandler() {
061        this.dataset = null;
062    }
063
064    /**
065     * Returns the dataset.
066     *
067     * @return The dataset.
068     */
069    public CategoryDataset getDataset() {
070        return this.dataset;
071    }
072
073    /**
074     * Adds an item to the dataset.
075     *
076     * @param rowKey  the row key.
077     * @param columnKey  the column key.
078     * @param value  the value.
079     */
080    public void addItem(Comparable rowKey, Comparable columnKey, Number value) {
081        this.dataset.addValue(value, rowKey, columnKey);
082    }
083
084    /**
085     * The start of an element.
086     *
087     * @param namespaceURI  the namespace.
088     * @param localName  the element name.
089     * @param qName  the element name.
090     * @param atts  the element attributes.
091     *
092     * @throws SAXException for errors.
093     */
094    public void startElement(String namespaceURI,
095                             String localName,
096                             String qName,
097                             Attributes atts) throws SAXException {
098
099        DefaultHandler current = getCurrentHandler();
100        if (current != this) {
101            current.startElement(namespaceURI, localName, qName, atts);
102        }
103        else if (qName.equals(CATEGORYDATASET_TAG)) {
104            this.dataset = new DefaultCategoryDataset();
105        }
106        else if (qName.equals(SERIES_TAG)) {
107            CategorySeriesHandler subhandler = new CategorySeriesHandler(this);
108            getSubHandlers().push(subhandler);
109            subhandler.startElement(namespaceURI, localName, qName, atts);
110        }
111        else {
112            throw new SAXException("Element not recognised: " + qName);
113        }
114
115    }
116
117    /**
118     * The end of an element.
119     *
120     * @param namespaceURI  the namespace.
121     * @param localName  the element name.
122     * @param qName  the element name.
123     *
124     * @throws SAXException for errors.
125     */
126    public void endElement(String namespaceURI,
127                           String localName,
128                           String qName) throws SAXException {
129
130        DefaultHandler current = getCurrentHandler();
131        if (current != this) {
132            current.endElement(namespaceURI, localName, qName);
133        }
134
135    }
136
137}