ActionMenuItem


1   /* ========================================================================
2    * JCommon : a free general purpose class library for the Java(tm) platform
3    * ========================================================================
4    *
5    * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
6    * 
7    * Project Info:  http://www.jfree.org/jcommon/index.html
8    *
9    * This library is free software; you can redistribute it and/or modify it 
10   * under the terms of the GNU Lesser General Public License as published by 
11   * the Free Software Foundation; either version 2.1 of the License, or 
12   * (at your option) any later version.
13   *
14   * This library is distributed in the hope that it will be useful, but 
15   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
16   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
17   * License for more details.
18   *
19   * You should have received a copy of the GNU Lesser General Public
20   * License along with this library; if not, write to the Free Software
21   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
22   * USA.  
23   *
24   * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
25   * in the United States and other countries.]
26   * 
27   * -------------------
28   * ActionMenuItem.java
29   * -------------------
30   * (C)opyright 2002-2004, by Thomas Morgner and Contributors.
31   *
32   * Original Author:  Thomas Morgner;
33   * Contributor(s):   David Gilbert (for Object Refinery Limited);
34   *
35   * $Id: ActionMenuItem.java,v 1.4 2005/10/18 13:22:12 mungady Exp $
36   *
37   * ChangeLog
38   * ---------
39   * 30-Aug-2002 : Initial version
40   * 01-Aug-2002 : Documentation
41   * 10-Dec-2002 : Minor Javadoc updates (DG);
42   *
43   */
44  
45  package org.jfree.ui.action;
46  
47  import java.beans.PropertyChangeEvent  ;
48  import java.beans.PropertyChangeListener  ;
49  import java.awt.event.KeyEvent  ;
50  import javax.swing.Action  ;
51  import javax.swing.Icon  ;
52  import javax.swing.JMenuItem  ;
53  import javax.swing.KeyStroke  ;
54  
55  import org.jfree.util.Log;
56  
57  /**
58   * The ActionMenuItem is used to connect an Action and its properties to an
59   * MenuItem.
60   * <p/>
61   * This functionality is already implemented in JDK 1.3 but needed for JDK 1.2.2
62   * compatibility.
63   *
64   * @author Thomas Morgner
65   */
66  public class ActionMenuItem extends JMenuItem  
67  {
68  
69    /** The action. */
70    private Action   action;
71  
72    /** The property change handler. */
73    private ActionEnablePropertyChangeHandler propertyChangeHandler;
74  
75    /**
76     * Helperclass to handle the property change event raised by the action.
77     * Changed properties in the action will affect the button.
78     */
79    private class ActionEnablePropertyChangeHandler
80            implements PropertyChangeListener  
81    {
82      public ActionEnablePropertyChangeHandler()
83      {
84      }
85  
86      /**
87       * Receives notification of a property change event.
88       *
89       * @param event the property change event.
90       */
91      public void propertyChange(final PropertyChangeEvent   event)
92      {
93        try
94        {
95          if (event.getPropertyName().equals("enabled"))
96          {
97            setEnabled(getAction().isEnabled());
98          }
99          else if (event.getPropertyName().equals(Action.SMALL_ICON))
100         {
101           setIcon((Icon  ) getAction().getValue(Action.SMALL_ICON));
102         }
103         else if (event.getPropertyName().equals(Action.NAME))
104         {
105           setText((String  ) getAction().getValue(Action.NAME));
106         }
107         else if (event.getPropertyName().equals(Action.SHORT_DESCRIPTION))
108         {
109           ActionMenuItem.this.setToolTipText((String  )
110                   getAction().getValue(Action.SHORT_DESCRIPTION));
111         }
112 
113         final Action   ac = getAction();
114         if (event.getPropertyName().equals(ActionDowngrade.ACCELERATOR_KEY))
115         {
116           setAccelerator((KeyStroke  ) ac.getValue(ActionDowngrade.ACCELERATOR_KEY));
117         }
118         else if (event.getPropertyName().equals(ActionDowngrade.MNEMONIC_KEY))
119         {
120           final Object   o = ac.getValue(ActionDowngrade.MNEMONIC_KEY);
121           if (o != null)
122           {
123             if (o instanceof Character  )
124             {
125               final Character   c = (Character  ) o;
126               setMnemonic(c.charValue());
127             }
128             else if (o instanceof Integer  )
129             {
130               final Integer   c = (Integer  ) o;
131               setMnemonic(c.intValue());
132             }
133           }
134           else
135           {
136             setMnemonic(KeyEvent.VK_UNDEFINED);
137           }
138         }
139       }
140       catch (Exception   e)
141       {
142         Log.warn("Error on PropertyChange in ActionButton: ", e);
143       }
144     }
145   }
146 
147   /** Default constructor. */
148   public ActionMenuItem()
149   {
150     // nothing required
151   }
152 
153   /**
154    * Creates a menu item with the specified icon.
155    *
156    * @param icon the icon.
157    */
158   public ActionMenuItem(final Icon   icon)
159   {
160     super(icon);
161   }
162 
163   /**
164    * Creates a menu item with the specified label.
165    *
166    * @param text the label.
167    */
168   public ActionMenuItem(final String   text)
169   {
170     super(text);
171   }
172 
173   /**
174    * Creates a menu item with the specified label and icon.
175    *
176    * @param text the label.
177    * @param icon the icon.
178    */
179   public ActionMenuItem(final String   text, final Icon   icon)
180   {
181     super(text, icon);
182   }
183 
184   /**
185    * Creates a new menu item with the specified label and mnemonic.
186    *
187    * @param text the label.
188    * @param i    the mnemonic.
189    */
190   public ActionMenuItem(final String   text, final int i)
191   {
192     super(text, i);
193   }
194 
195   /**
196    * Creates a new menu item based on the specified action.
197    *
198    * @param action the action.
199    */
200   public ActionMenuItem(final Action   action)
201   {
202     setAction(action);
203   }
204 
205   /**
206    * Returns the assigned action or null if no action has been assigned.
207    *
208    * @return the action.
209    */
210   public Action   getAction()
211   {
212     return this.action;
213   }
214 
215   /**
216    * Returns and initializes the PropertyChangehandler for this ActionMenuItem.
217    * The PropertyChangeHandler monitors the action and updates the menuitem if
218    * necessary.
219    *
220    * @return the property change handler.
221    */
222   private ActionEnablePropertyChangeHandler getPropertyChangeHandler()
223   {
224     if (this.propertyChangeHandler == null)
225     {
226       this.propertyChangeHandler = new ActionEnablePropertyChangeHandler();
227     }
228     return this.propertyChangeHandler;
229   }
230 
231   /**
232    * Enables and disables this button and if an action is assigned to this
233    * menuitem the propertychange is forwarded to the assigned action.
234    *
235    * @param b the new enable-state of this menuitem
236    */
237   public void setEnabled(final boolean b)
238   {
239     super.setEnabled(b);
240     if (getAction() != null)
241     {
242       getAction().setEnabled(b);
243     }
244   }
245 
246   /**
247    * Assigns the given action to this menuitem. The properties of the action
248    * will be assigned to the menuitem. If an previous action was set, the old
249    * action is unregistered.
250    * <p/>
251    * <ul> <li>NAME - specifies the menuitem text <li>SMALL_ICON - specifies the
252    * menuitems icon <li>MNEMONIC_KEY - specifies the menuitems mnemonic key
253    * <li>ACCELERATOR_KEY - specifies the menuitems accelerator </ul>
254    *
255    * @param newAction the new action
256    */
257   public void setAction(final Action   newAction)
258   {
259     final Action   oldAction = getAction();
260     if (oldAction != null)
261     {
262       removeActionListener(oldAction);
263       oldAction.removePropertyChangeListener(getPropertyChangeHandler());
264       setAccelerator(null);
265     }
266     this.action = newAction;
267     if (this.action != null)
268     {
269       addActionListener(newAction);
270       newAction.addPropertyChangeListener(getPropertyChangeHandler());
271 
272       setText((String  ) (newAction.getValue(Action.NAME)));
273       setToolTipText((String  ) (newAction.getValue(Action.SHORT_DESCRIPTION)));
274       setIcon((Icon  ) newAction.getValue(Action.SMALL_ICON));
275       setEnabled(this.action.isEnabled());
276 
277       Object   o = newAction.getValue(ActionDowngrade.MNEMONIC_KEY);
278       if (o != null)
279       {
280         if (o instanceof Character  )
281         {
282           final Character   c = (Character  ) o;
283           setMnemonic(c.charValue());
284         }
285         else if (o instanceof Integer  )
286         {
287           final Integer   c = (Integer  ) o;
288           setMnemonic(c.intValue());
289         }
290       }
291       else
292       {
293         setMnemonic(KeyEvent.VK_UNDEFINED);
294       }
295 
296 
297       o = newAction.getValue(ActionDowngrade.ACCELERATOR_KEY);
298       if (o instanceof KeyStroke  )
299       {
300         setAccelerator((KeyStroke  ) o);
301       }
302     }
303   }
304 }
305
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