    001    /* ===========================================================
    002     * JFreeChart : a free chart library for the Java(tm) platform
    003     * ===========================================================
    004     *
    005     * (C) Copyright 2000-2007, 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 2003-2007, 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    }