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 jgb.builder.TagHandler;
023 import jgb.builder.WindowContext;
024 import org.xml.sax.SAXException;
025
026 import java.lang.reflect.InvocationHandler;
027 import java.lang.reflect.Method;
028 import java.lang.reflect.Proxy;
029 import java.util.EventObject;
030 import java.util.Map;
031
032 public class RegisterTagHandler extends AbstractTagHandler {
033 public static final String ATTR_METHOD = "method";
034 public static final String ATTR_MANAGER = "manager";
035 public static final String ATTR_EVENT = "event";
036
037 protected void enterElement(Map atts) throws SAXException {
038 String className = (String)atts.get(ATTR_CLASS);
039 String eventName = (String)atts.get(ATTR_EVENT);
040 String managerName = (String)atts.get(ATTR_MANAGER);
041 String methodName = (String)atts.get(ATTR_METHOD);
042
043 try {
044 Class listenerClass;
045 try {
046 listenerClass = Class.forName(className);
047 } catch (ClassNotFoundException e) {
048 try {
049 listenerClass = Class.forName("java.awt.event." + className);
050 } catch (ClassNotFoundException e1) {
051 listenerClass = Class.forName("javax.swing.event." + className);
052 }
053 }
054
055 if (!listenerClass.isInterface()) {
056 throwParsingException("register listener class must be an interface",
057 new IllegalArgumentException(listenerClass.getName()));
058 }
059
060 final Object managerObject = getObject(managerName);
061 final Method reflectedEventMethod = managerObject.getClass()
062 .getMethod(methodName,
063 new Class[]{
064 EventObject.class,
065 WindowContext.class}
066 );
067 final Object listenerInstance = Proxy.newProxyInstance(
068 this.getClass().getClassLoader(),
069 new Class[]{listenerClass},
070 new EventReflector(
071 eventName, managerObject, reflectedEventMethod,
072 (WindowContext)tagContext.get(TagHandler.WINDOW_CONTEXT_KEY)
073 )
074 );
075
076 final Object parentObject = getCurrentObject();
077 final Class parentObjectClass = parentObject.getClass();
078 final String listenerClassName;
079 final int lastDot = listenerClass.getName().lastIndexOf('.');
080 listenerClassName = listenerClass.getName().substring(1 + lastDot);
081 final Method addListenerMethod = parentObjectClass.getMethod(
082 "add" + listenerClassName, new Class[]{listenerClass});
083 addListenerMethod.invoke(parentObject,
084 new Object[]{listenerInstance});
085 } catch (SAXException e) {
086 throw e;
087 } catch (Exception e) {
088 throwParsingException("Unable to register event listener for event " +
089 eventName + " on object " + getCurrentObjectId() + " for " +
090 "class " + className, e);
091 }
092 }
093
094 protected void exitElement() throws SAXException {
095 }
096
097 private static final class EventReflector implements InvocationHandler {
098 private final String eventName;
099 private final Object managerObject;
100 private final Method reflectedEventMethod;
101 private final WindowContext windowContext;
102
103 public EventReflector(String eventName, Object managerObject, Method reflectedEventMethod, WindowContext windowContext) {
104 this.eventName = eventName;
105 this.managerObject = managerObject;
106 this.reflectedEventMethod = reflectedEventMethod;
107 this.windowContext = windowContext;
108 }
109
110 public Object invoke(Object proxy, Method method, Object[] args)
111 throws Throwable {
112 if (eventName.equals(method.getName())) {
113 reflectedEventMethod.invoke(
114 managerObject,
115 new Object[]{args[0], windowContext}
116 );
117 }
118 return null;
119 }
120 }
121 }