    001/* ===========================================================
    002 * JFreeChart : a free chart library for the Java(tm) platform
    003 * ===========================================================
    004 *
    005 * (C) Copyright 2000-2011, 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 * [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 * KeyHandler.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.xml.sax.Attributes;
    044import org.xml.sax.SAXException;
    045import org.xml.sax.helpers.DefaultHandler;
    046
    047/**
    048 * A SAX handler for reading a key.
    049 */
    050public class KeyHandler extends DefaultHandler implements DatasetTags {
    051
    052    /** The root handler. */
    053    private RootHandler rootHandler;
    054
    055    /** The item handler. */
    056    private ItemHandler itemHandler;
    057
    058    /** Storage for the current CDATA */
    059    private StringBuffer currentText;
    060
    061    /** The key. */
    062    //private Comparable key;
    063
    064    /**
    065     * Creates a new handler.
    066     *
    067     * @param rootHandler  the root handler.
    068     * @param itemHandler  the item handler.
    069     */
    070    public KeyHandler(RootHandler rootHandler, ItemHandler itemHandler) {
    071        this.rootHandler = rootHandler;
    072        this.itemHandler = itemHandler;
    073        this.currentText = new StringBuffer();
    074        //this.key = null;
    075    }
    076
    077    /**
    078     * The start of an element.
    079     *
    080     * @param namespaceURI  the namespace.
    081     * @param localName  the element name.
    082     * @param qName  the element name.
    083     * @param atts  the attributes.
    084     *
    085     * @throws SAXException for errors.
    086     */
    087    public void startElement(String namespaceURI,
    088                             String localName,
    089                             String qName,
    090                             Attributes atts) throws SAXException {
    091
    092        if (qName.equals(KEY_TAG)) {
    093            clearCurrentText();
    094        }
    095        else {
    096            throw new SAXException("Expecting <Key> but found " + qName);
    097        }
    098
    099    }
    100
    101    /**
    102     * The end of an element.
    103     *
    104     * @param namespaceURI  the namespace.
    105     * @param localName  the element name.
    106     * @param qName  the element name.
    107     *
    108     * @throws SAXException for errors.
    109     */
    110    public void endElement(String namespaceURI,
    111                           String localName,
    112                           String qName) throws SAXException {
    113
    114        if (qName.equals(KEY_TAG)) {
    115            this.itemHandler.setKey(getCurrentText());
    116            this.rootHandler.popSubHandler();
    117            this.rootHandler.pushSubHandler(
    118                new ValueHandler(this.rootHandler, this.itemHandler)
    119            );
    120        }
    121        else {
    122            throw new SAXException("Expecting </Key> but found " + qName);
    123        }
    124
    125    }
    126
    127    /**
    128     * Receives some (or all) of the text in the current element.
    129     *
    130     * @param ch  character buffer.
    131     * @param start  the start index.
    132     * @param length  the length of the valid character data.
    133     */
    134    public void characters(char[] ch, int start, int length) {
    135        if (this.currentText != null) {
    136            this.currentText.append(String.copyValueOf(ch, start, length));
    137        }
    138    }
    139
    140    /**
    141     * Returns the current text of the textbuffer.
    142     *
    143     * @return The current text.
    144     */
    145    protected String getCurrentText() {
    146        return this.currentText.toString();
    147    }
    148
    149    /**
    150     * Removes all text from the textbuffer at the end of a CDATA section.
    151     */
    152    protected void clearCurrentText() {
    153        this.currentText.delete(0, this.currentText.length());
    154    }
    155
    156}