001    /**
002     * Java Gui Builder - A library to build GUIs using an XML file.
003     * Copyright 2002, 2003 (C) François Beausoleil
004     *
005     * This library is free software; you can redistribute it and/or
006     * modify it under the terms of the GNU Lesser General Public
007     * License as published by the Free Software Foundation; either
008     * version 2.1 of the License, or (at your option) any later version.
009     *
010     * This library is distributed in the hope that it will be useful,
011     * but WITHOUT ANY WARRANTY; without even the implied warranty of
012     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
013     * Lesser General Public License for more details.
014     *
015     * You should have received a copy of the GNU Lesser General Public
016     * License along with this library; if not, write to the Free Software
017     * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
018     */
019    
020    package jgb.handlers.swing;
021    
022    import org.xml.sax.SAXException;
023    
024    import javax.swing.*;
025    import java.awt.*;
026    import java.util.Map;
027    
028    /**
029     * @since 0.1a
030     * @author Francois Beausoleil, <a href="mailto:fbos@users.sourceforge.net">fbos@users.sourceforge.net</a>
031     */
032    public class ControlTagHandler extends AbstractControlTagHandler {
033        private static final String DEFAULT_PACKAGE = "javax.swing.";
034    
035        public void enterElement(Map atts) throws SAXException {
036            String controlClassName = calcControlClassName((String)atts.get(ATTR_CLASS));
037            Component currentControl = createComponent(controlClassName);
038            currentControl.setName((String)atts.get(ATTR_ID));
039    
040            if (atts.containsKey(ATTR_ID)) {
041                putObject((String)atts.get(ATTR_ID), currentControl);
042            }
043    
044            if (atts.containsKey(ATTR_REFLABEL)) {
045                JLabel referrent = (JLabel)getObject(atts.get(ATTR_REFLABEL).toString());
046                referrent.setLabelFor(currentControl);
047            }
048    
049            pushCurrentControl(currentControl, (String)atts.get(ATTR_ID));
050        }
051    
052        public void exitElement() throws SAXException {
053            popCurrentControl();
054        }
055    
056        protected String getDefaultPackagePrefix() {
057            return DEFAULT_PACKAGE;
058        }
059    
060        private Component createComponent(String className) throws SAXException {
061            if (className == null) {
062                throwParsingException("attribute 'class' is required on control elements");
063            }
064    
065            Component control = null;
066            try {
067                Class controlClass = Class.forName(className);
068                control = (Component)controlClass.newInstance();
069            } catch (Exception e) {
070                throwParsingException("Class " + className + " could not be instantiated", e);
071            }
072    
073            return control;
074        }
075    }