1 /* CheckboxMenuItem.java -- A menu option with a checkbox on it.
2 Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005 Free Software Foundation, Inc.
4 This file is part of GNU Classpath.
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING. If not, write to the
18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
41 import java
.awt
.event
.ItemEvent
;
42 import java
.awt
.event
.ItemListener
;
43 import java
.awt
.peer
.CheckboxMenuItemPeer
;
44 import java
.util
.EventListener
;
46 import javax
.accessibility
.Accessible
;
47 import javax
.accessibility
.AccessibleAction
;
48 import javax
.accessibility
.AccessibleContext
;
49 import javax
.accessibility
.AccessibleValue
;
52 * This class implements a menu item that has a checkbox on it indicating
53 * the selected state of some option.
55 * @author Aaron M. Renn (arenn@urbanophile.com)
56 * @author Tom Tromey (tromey@redhat.com)
58 public class CheckboxMenuItem
extends MenuItem
59 implements ItemSelectable
, Accessible
66 // Serialization constant
67 private static final long serialVersionUID
= 6190621106981774043L;
74 * @serial The state of the checkbox, with <code>true</code> being on and
75 * <code>false</code> being off.
77 private boolean state
;
79 // List of registered ItemListeners
80 private transient ItemListener item_listeners
;
82 /*************************************************************************/
89 * Initializes a new instance of <code>CheckboxMenuItem</code> with no
90 * label and an initial state of off.
92 * @exception HeadlessException If GraphicsEnvironment.isHeadless()
101 /*************************************************************************/
104 * Initializes a new instance of <code>CheckboxMenuItem</code> with the
105 * specified label and an initial state of off.
107 * @param label The label of the menu item.
109 * @exception HeadlessException If GraphicsEnvironment.isHeadless()
113 CheckboxMenuItem(String label
)
118 /*************************************************************************/
121 * Initializes a new instance of <code>CheckboxMenuItem</code> with the
122 * specified label and initial state.
124 * @param label The label of the menu item.
125 * @param state The initial state of the menu item, where <code>true</code>
126 * is on, and <code>false</code> is off.
128 * @exception HeadlessException If GraphicsEnvironment.isHeadless()
132 CheckboxMenuItem(String label
, boolean state
)
137 if (GraphicsEnvironment
.isHeadless())
138 throw new HeadlessException ();
141 /*************************************************************************/
148 * Returns the state of this menu item.
150 * @return The state of this menu item.
158 /*************************************************************************/
161 * Sets the state of this menu item.
163 * @param state The initial state of the menu item, where <code>true</code>
164 * is on, and <code>false</code> is off.
166 public synchronized void
167 setState(boolean state
)
172 CheckboxMenuItemPeer cp
= (CheckboxMenuItemPeer
) peer
;
177 /*************************************************************************/
180 * Returns an array of length 1 with the menu item label for this object
181 * if the state is on. Otherwise <code>null</code> is returned.
183 * @return An array with this menu item's label if it has a state of on,
184 * or <code>null</code> otherwise.
192 Object
[] obj
= new Object
[1];
198 /*************************************************************************/
201 * Create's this object's native peer
203 public synchronized void
207 peer
= getToolkit().createCheckboxMenuItem(this);
212 /*************************************************************************/
215 * Adds the specified listener to the list of registered item listeners
218 * @param listener The listener to add.
220 public synchronized void
221 addItemListener(ItemListener listener
)
223 item_listeners
= AWTEventMulticaster
.add(item_listeners
, listener
);
225 enableEvents(AWTEvent
.ITEM_EVENT_MASK
);
228 /*************************************************************************/
231 * Removes the specified listener from the list of registered item
232 * listeners for this object.
234 * @param listener The listener to remove.
236 public synchronized void
237 removeItemListener(ItemListener listener
)
239 item_listeners
= AWTEventMulticaster
.remove(item_listeners
, listener
);
242 /*************************************************************************/
245 * Processes the specified event by calling <code>processItemEvent()</code>
246 * if it is an instance of <code>ItemEvent</code> or calling the superclass
249 * @param event The event to process.
252 processEvent(AWTEvent event
)
254 if (event
instanceof ItemEvent
)
255 processItemEvent((ItemEvent
)event
);
257 super.processEvent(event
);
260 /*************************************************************************/
263 * Processes the specified event by dispatching it to any registered listeners.
265 * @param event The event to process.
268 processItemEvent(ItemEvent event
)
270 if (item_listeners
!= null)
271 item_listeners
.itemStateChanged(event
);
275 dispatchEventImpl(AWTEvent e
)
277 if (e
instanceof ItemEvent
)
281 state
= (((ItemEvent
) e
).getStateChange() == ItemEvent
.SELECTED
);
285 if (e
.id
<= ItemEvent
.ITEM_LAST
286 && e
.id
>= ItemEvent
.ITEM_FIRST
287 && (item_listeners
!= null
288 || (eventMask
& AWTEvent
.ITEM_EVENT_MASK
) != 0))
291 super.dispatchEventImpl(e
);
294 /*************************************************************************/
297 * Returns a debugging string for this object.
299 * @return A debugging string for this object.
304 return ("label=" + getLabel() + ",state=" + state
305 + "," + super.paramString());
309 * Returns an array of all the objects currently registered as FooListeners
310 * upon this <code>CheckboxMenuItem</code>. FooListeners are registered using
311 * the addFooListener method.
313 * @exception ClassCastException If listenerType doesn't specify a class or
314 * interface that implements java.util.EventListener.
316 public EventListener
[] getListeners (Class listenerType
)
318 if (listenerType
== ItemListener
.class)
319 return AWTEventMulticaster
.getListeners (item_listeners
, listenerType
);
321 return super.getListeners (listenerType
);
325 * Returns an aray of all item listeners currently registered to this
326 * <code>CheckBoxMenuItem</code>.
328 public ItemListener
[] getItemListeners ()
330 return (ItemListener
[]) getListeners (ItemListener
.class);
334 protected class AccessibleAWTCheckboxMenuItem
extends AccessibleAWTMenuItem
335 implements AccessibleAction
, AccessibleValue
337 // I think the base class provides the necessary implementation
341 * Gets the AccessibleContext associated with this <code>CheckboxMenuItem</code>.
342 * The context is created, if necessary.
344 * @return the associated context
346 public AccessibleContext
getAccessibleContext()
348 /* Create the context if this is the first request */
349 if (accessibleContext
== null)
350 accessibleContext
= new AccessibleAWTCheckboxMenuItem();
351 return accessibleContext
;
354 } // class CheckboxMenuItem