Source code

001/*
002 * $Id: BoundAction.java 3972 2011-03-17 20:31:58Z kschaefe $
003 *
004 * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle,
005 * Santa Clara, California 95054, U.S.A. All rights reserved.
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 * 
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
015 * Lesser General Public License for more details.
016 * 
017 * You should have received a copy of the GNU Lesser General Public
018 * License along with this library; if not, write to the Free Software
019 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
020 */
021
022package org.jdesktop.swingx.action;
023
024import java.awt.event.ActionEvent;
025import java.awt.event.ActionListener;
026import java.awt.event.ItemEvent;
027import java.awt.event.ItemListener;
028import java.beans.EventHandler;
029import java.beans.Statement;
030import java.io.IOException;
031import java.io.ObjectInputStream;
032import java.io.ObjectOutputStream;
033import java.io.Serializable;
034import java.lang.reflect.InvocationHandler;
035import java.lang.reflect.Proxy;
036import java.util.EventListener;
037import java.util.logging.Level;
038import java.util.logging.Logger;
039
040import javax.swing.Icon;
041import javax.swing.event.EventListenerList;
042
043/**
044 * A class that represents the many type of actions that this framework supports.
045 * <p>
046 * The command invocation of this action may be delegated to another action or item state
047 * listener. If there isn't an explicit binding then the command is forwarded to 
048 * the TargetManager.
049 *
050 * @author Mark Davidson
051 * @author Karl Schaefer (serialization support)
052 */
053public class BoundAction extends AbstractActionExt {
054    private static final Logger LOG = Logger.getLogger(BoundAction.class .getName());
055    
056    // Holds the listeners
057    private transient EventListenerList listeners;
058
059    public BoundAction() {
060        this("BoundAction");
061    }
062
063    public BoundAction(String name) {
064        super(name);
065    }
066
067    /**
068     * @param name display name of the action
069     * @param command the value of the action command key
070     */
071    public BoundAction(String name, String command) {
072        super(name, command);
073    }
074
075    public BoundAction(String name, Icon icon) {
076        super(name, icon);
077    }
078
079    /**
080     * @param name display name of the action
081     * @param command the value of the action command key
082     * @param icon icon to display
083     */
084    public BoundAction(String name, String command, Icon icon) {
085        super(name, command, icon);
086    }
087
088    /**
089     * The callback string will be called to register the action callback.
090     * Note the toggle property must be set if this is a state action before
091     * this method is called.
092     * For example, 
093     * <pre>
094     *     &lt;exec&gt;com.sun.foo.FubarHandler#handleBar&lt;/exec&gt;
095     * </pre>
096     * will register
097     * <pre>
098     *     registerCallback(com.sun.foo.FubarHandler(), "handleBar");
099     * </pre>
100     */
101    public void setCallback(String callback) {
102        String[] elems = callback.split("#", 2);
103        if (elems.length == 2) {
104            try {
105                Class<?> clz = Class.forName(elems[0]);
106
107                // May throw a security exception in an Applet
108                // context.
109                Object obj = clz.newInstance();
110
111                registerCallback(obj, elems[1]);
112            } catch (Exception ex) {
113                LOG.fine("ERROR: setCallback(" + callback
114                                   + ") - " + ex.getMessage());
115            }
116        }
117    }
118
119    /**
120     * Registers a callback method when the Action corresponding to
121     * the action id is invoked. When a Component that was constructed from the
122     * Action identified by the action id invokes actionPerformed then the method
123     * named will be invoked on the handler Object.
124     * <p>
125     * If the Action represented by the action id is a StateChangeAction, then
126     * the method passed should take an int as an argument. The value of
127     * getStateChange() on the ItemEvent object will be passed as the parameter.
128     *
129     * @param handler the object which will be perform the action
130     * @param method the name of the method on the handler which will be called.
131     */
132    public void registerCallback(Object handler, String method) {
133        if (isStateAction()) {
134            // Create a handler for toggle type actions.
135            addItemListener(new BooleanInvocationHandler(handler, method));
136        } else {
137            // Create a new ActionListener using the dynamic proxy API.
138            addActionListener(EventHandler.create(ActionListener.class,
139                                                                  handler, method));
140        }
141    }
142    
143    /**
144     * The callback for the toggle/state changed action that invokes a method 
145     * with a boolean argument on a target.
146     *
147     * TODO: should reimplement this class as something that can be persistable.
148     */
149    private class BooleanInvocationHandler implements ItemListener {
150
151        private Statement falseStatement;
152        private Statement trueStatement;
153
154        public BooleanInvocationHandler(Object target, String methodName) {
155            // Create the true and false statements.
156            falseStatement = new Statement(target, methodName, 
157                                           new Object[] { Boolean.FALSE });
158            
159            trueStatement = new Statement(target, methodName, 
160                                          new Object[] { Boolean.TRUE });
161        }
162
163        @Override
164        public void itemStateChanged(ItemEvent evt) {
165            Statement statement = (evt.getStateChange() == ItemEvent.DESELECTED) ? falseStatement
166                    : trueStatement;
167
168            try {
169                statement.execute();
170            } catch (Exception ex) {
171                LOG.log(Level.FINE,
172                        "Couldn't execute boolean method via Statement "
173                                + statement, ex);
174            }
175        }
176    }
177
178    // Listener registration...
179
180    private <T extends EventListener> void addListener(Class<T> clz, T listener) {
181        if (listeners == null) {
182            listeners = new EventListenerList();
183        }
184        listeners.add(clz, listener);        
185    }
186
187    private <T extends EventListener> void removeListener(Class<T> clz, T listener) {
188        if (listeners != null) {
189            listeners.remove(clz, listener);
190        }
191    }
192
193    private EventListener[] getListeners(Class<? extends EventListener> clz) {
194        if (listeners == null) {
195            return null;
196        }
197        return listeners.getListeners(clz);
198    }
199
200    /**
201     * Add an action listener which will be invoked when this action is invoked.
202     */
203    public void addActionListener(ActionListener listener) {
204        addListener(ActionListener.class, listener);
205    }
206
207    public void removeActionListener(ActionListener listener) {
208        removeListener(ActionListener.class, listener);
209    }
210
211    public ActionListener[] getActionListeners() {
212        return (ActionListener[])getListeners(ActionListener.class);
213    }
214
215    /**
216     * Add an item listener which will be invoked for toggle actions.
217     */
218    public void addItemListener(ItemListener listener) {
219        addListener(ItemListener.class, listener);
220    }
221
222    public void removeItemListener(ItemListener listener) {
223        removeListener(ItemListener.class, listener);
224    }
225
226    public ItemListener[] getItemListeners() {
227        return (ItemListener[])getListeners(ItemListener.class);
228    }
229
230    // Callbacks...
231
232    /**
233     * Callback for command actions.
234     */
235    @Override
236    public void actionPerformed(ActionEvent evt) {
237        ActionListener[] alist = getActionListeners();
238        if (alist != null) {
239            for (int i = 0 ; i < alist.length; i++) {
240                alist[i].actionPerformed(evt);
241            }
242        }
243    }
244
245    /**
246     * Callback for toggle actions.
247     */
248    @Override
249    public void itemStateChanged(ItemEvent evt) {
250        // Update all objects that share this item
251        boolean newValue;
252        boolean oldValue = isSelected();
253
254        newValue = evt.getStateChange() == ItemEvent.SELECTED;
255
256        if (oldValue != newValue) {
257            setSelected(newValue);
258
259            // Forward the event to the delgate for handling.
260            ItemListener[] ilist = getItemListeners();
261            if (ilist != null) {
262                for (int i = 0; i < ilist.length; i++) {
263                    ilist[i].itemStateChanged(evt);
264                }
265            }
266        }
267    }
268
269    private void writeObject(ObjectOutputStream s) throws IOException {
270        s.defaultWriteObject();
271
272        if (listeners != null) {
273            Object[] list = listeners.getListenerList();
274            
275            for (int i = 1; i < list.length; i += 2) {
276                if (Proxy.isProxyClass(list[i].getClass())) {
277                    InvocationHandler h = Proxy.getInvocationHandler(list[i]);
278                    
279                    if (h instanceof EventHandler && ((EventHandler) h).getTarget() instanceof Serializable) {
280                        EventHandler eh = (EventHandler) h;
281                        
282                        s.writeObject("callback");
283                        s.writeObject(eh.getTarget());
284                        s.writeObject(eh.getAction());
285                    }
286                } else if (list[i] instanceof BooleanInvocationHandler) {
287                    BooleanInvocationHandler bih = (BooleanInvocationHandler) list[i];
288                    Object target = bih.trueStatement.getTarget();
289                    
290                    if (target instanceof Serializable) {
291                        s.writeObject(BooleanInvocationHandler.class.getName());
292                        s.writeObject(target);
293                        s.writeObject(bih.trueStatement.getMethodName());
294                    }
295                } else if (list[i] instanceof Serializable) {
296                    s.writeObject(((Class<?>) list[i - 1]).getName());
297                    s.writeObject(list[i]);
298                }
299            }
300        }
301
302        s.writeObject(null);
303    }
304
305    @SuppressWarnings("unchecked")
306    private void readObject(ObjectInputStream s) throws ClassNotFoundException,
307            IOException {
308        s.defaultReadObject();
309
310        Object typeOrNull;
311        
312        while (null != (typeOrNull = s.readObject())) {
313            if ("callback".equals(typeOrNull)) {
314                Object handler = s.readObject();
315                String method = (String) s.readObject();
316                
317                addActionListener(EventHandler.create(ActionListener.class, handler, method));
318            } else if (BooleanInvocationHandler.class.getName().equals(typeOrNull)) {
319                Object handler = s.readObject();
320                String method = (String) s.readObject();
321                
322                addItemListener(new BooleanInvocationHandler(handler, method));
323            } else {
324                ClassLoader cl = Thread.currentThread().getContextClassLoader();
325                EventListener l = (EventListener) s.readObject();
326                addListener((Class<EventListener>)Class.forName((String)typeOrNull, true, cl), l);
327            }
328        }
329    }
330}