    001    /* ========================================================================
    002     * JCommon : a free general purpose class 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/jcommon/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     * GradientPaintReadHandler
    029     * ------------------------
    030     * (C) Copyright 2003, by Thomas Morgner and Contributors.
    031     *
    032     * Original Author:  Thomas Morgner;
    033     * Contributor(s):   David Gilbert (for Object Refinery Limited);
    034     *
    035     * $Id: GradientPaintReadHandler.java,v 1.2 2005/10/18 13:33:32 mungady Exp $
    036     *
    037     * Changes (from 25-Nov-2003)
    038     * --------------------------
    039     * 25-Nov-2003 : Added standard header and Javadocs (DG);
    040     *
    041     */
    042
    043    package org.jfree.xml.parser.coretypes;
    044
    045    import java.awt.Color;
    046    import java.awt.GradientPaint;
    047    import java.awt.geom.Point2D;
    048
    049    import org.jfree.xml.parser.AbstractXmlReadHandler;
    050    import org.jfree.xml.parser.XmlReadHandler;
    051    import org.jfree.xml.parser.XmlReaderException;
    052    import org.xml.sax.Attributes;
    053    import org.xml.sax.SAXException;
    054
    055    /**
    056     * A SAX handler for reading a {@link GradientPaint} from an XML element.
    057     */
    058    public class GradientPaintReadHandler extends AbstractXmlReadHandler  {
    059
    060        /** The gradient paint under construction. */
    061        private GradientPaint gradient;
    062
    063        /** The handler for color 1. */
    064        private XmlReadHandler color1Handler;
    065
    066        /** The handler for color 2. */
    067        private XmlReadHandler color2Handler;
    068
    069        /** The handler for point 1. */
    070        private XmlReadHandler point1Handler;
    071
    072        /** The handler for point 2. */
    073        private XmlReadHandler point2Handler;
    074
    075        /**
    076         * Creates a new handler.
    077         */
    078        public GradientPaintReadHandler() {
    079            super();
    080        }
    081
    082        /**
    083         * Returns the gradient paint under construction.
    084         *
    085         * @return the gradient paint.
    086         */
    087        public Object getObject() {
    088            return this.gradient;
    089        }
    090
    091        /**
    092         * Returns the handler for a child element.
    093         *
    094         * @param tagName  the tag name.
    095         * @param atts  the attributes.
    096         *
    097         * @return the handler.
    098         * @throws SAXException to indicate a parsing error.
    099         * @throws XmlReaderException if there is a reader error.
    100         */
    101        protected XmlReadHandler getHandlerForChild(final String tagName, final Attributes atts)
    102            throws SAXException, XmlReaderException {
    103            if ("color1".equals(tagName)) {
    104                this.color1Handler = getRootHandler().createHandler(Color.class, tagName, atts);
    105                return this.color1Handler;
    106            }
    107            else if ("color2".equals(tagName)) {
    108                this.color2Handler = getRootHandler().createHandler(Color.class, tagName, atts);
    109                return this.color2Handler;
    110            }
    111            else if ("point1".equals(tagName)) {
    112                this.point1Handler = getRootHandler().createHandler(Point2D.class, tagName, atts);
    113                return this.point1Handler;
    114            }
    115            else if ("point2".equals(tagName)) {
    116                this.point2Handler = getRootHandler().createHandler(Point2D.class, tagName, atts);
    117                return this.point2Handler;
    118            }
    119            return null;
    120        }
    121
    122        /**
    123         * At the end of parsing the element, the gradient paint is constructed.
    124         *
    125         * @throws XmlReaderException if there is a parsing error.
    126         */
    127        protected void doneParsing() throws XmlReaderException {
    128            if (this.point1Handler == null || this.point2Handler == null
    129                || this.color1Handler == null || this.color2Handler == null) {
    130                throw new XmlReaderException("Not all required subelements are defined.");
    131            }
    132            this.gradient = new GradientPaint
    133                ((Point2D) this.point1Handler.getObject(),
    134                (Color) this.color1Handler.getObject(),
    135                (Point2D) this.point2Handler.getObject(),
    136                (Color) this.color2Handler.getObject());
    137        }
    138
    139    }