/* ===========================================================

 * JFreeChart : a free chart library for the Java(tm) platform

 * ===========================================================

 *

 * (C) Copyright 2000-2004, by Object Refinery Limited and Contributors.

 *

 * Project Info:  http://www.jfree.org/jfreechart/index.html

 *

 * This library is free software; you can redistribute it and/or modify it under the terms

 * of the GNU Lesser General Public License as published by the Free Software Foundation;

 * either version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;

 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 * See the GNU Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License along with this

 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,

 * Boston, MA 02111-1307, USA.

 *

 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 

 * in the United States and other countries.]

 *

 * ----------------------

 * PieDatasetHandler.java

 * ----------------------

 * (C) Copyright 2003, by Object Refinery Limited and Contributors.

 *

 * Original Author:  David Gilbert (for Object Refinery Limited);

 * Contributor(s):   -;

 *

 * $Id: PieDatasetHandler.java,v 1.1 2004/08/31 15:35:26 mungady Exp $

 *

 * Changes (from 21-Jun-2001)

 * --------------------------

 * 23-Jan-2003 : Version 1 (DG);

 *

 */



package org.jfree.data.xml;



import org.jfree.data.general.DefaultPieDataset;

import org.jfree.data.general.PieDataset;

import org.xml.sax.Attributes;

import org.xml.sax.SAXException;

import org.xml.sax.helpers.DefaultHandler;



/**

 * A SAX handler for reading a {@link PieDataset} from an XML file.

 *

 */

public class PieDatasetHandler extends RootHandler implements DatasetTags {



    /** The pie dataset under construction. */

    private DefaultPieDataset dataset;



    /**

     * Default constructor.

     */

    public PieDatasetHandler() {

        this.dataset = null;

    }



    /**

     * Returns the dataset.

     *

     * @return The dataset.

     */

    public PieDataset getDataset() {

        return this.dataset;

    }



    /**

     * Adds an item to the dataset under construction.

     *

     * @param key  the key.

     * @param value  the value.

     */

    public void addItem(final Comparable key, final Number value) {

        this.dataset.setValue(key, value);

    }



    /**

     * Starts an element.

     *

     * @param namespaceURI  the namespace.

     * @param localName  the element name.

     * @param qName  the element name.

     * @param atts  the element attributes.

     *

     * @throws SAXException for errors.

     */

    public void startElement(final String namespaceURI,

                             final String localName,

                             final String qName,

                             final Attributes atts) throws SAXException {



        final DefaultHandler current = getCurrentHandler();

        if (current != this) {

            current.startElement(namespaceURI, localName, qName, atts);

        }

        else if (qName.equals(PIEDATASET_TAG)) {

            this.dataset = new DefaultPieDataset();

        }

        else if (qName.equals(ITEM_TAG)) {

            final ItemHandler subhandler = new ItemHandler(this, this);

            getSubHandlers().push(subhandler);

            subhandler.startElement(namespaceURI, localName, qName, atts);

        }



    }



    /**

     * The end of an element.

     *

     * @param namespaceURI  the namespace.

     * @param localName  the element name.

     * @param qName  the element name.

     *

     * @throws SAXException for errors.

     */

    public void endElement(final String namespaceURI,

                           final String localName,

                           final String qName) throws SAXException {



        final DefaultHandler current = getCurrentHandler();

        if (current != this) {

            current.endElement(namespaceURI, localName, qName);

        }



    }



}

