1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package javax.swing;
26
27 import java.util.EventListener;
28
29 import java.awt.*;
30 import java.awt.event.*;
31 import java.awt.image.*;
32
33 import java.io.ObjectOutputStream;
34 import java.io.ObjectInputStream;
35 import java.io.IOException;
36
37 import javax.swing.plaf.*;
38 import javax.accessibility.*;
39
40 /**
41 * An implementation of a radio button menu item.
42 * A <code>JRadioButtonMenuItem</code> is
43 * a menu item that is part of a group of menu items in which only one
44 * item in the group can be selected. The selected item displays its
45 * selected state. Selecting it causes any other selected item to
46 * switch to the unselected state.
47 * To control the selected state of a group of radio button menu items,
48 * use a <code>ButtonGroup</code> object.
49 * <p>
50 * Menu items can be configured, and to some degree controlled, by
51 * <code><a href="Action.html">Action</a></code>s. Using an
52 * <code>Action</code> with a menu item has many benefits beyond directly
53 * configuring a menu item. Refer to <a href="Action.html#buttonActions">
54 * Swing Components Supporting <code>Action</code></a> for more
55 * details, and you can find more information in <a
56 * href="http://docs.oracle.com/javase/tutorial/uiswing/misc/action.html">How
57 * to Use Actions</a>, a section in <em>The Java Tutorial</em>.
58 * <p>
59 * For further documentation and examples see
60 * <a
61 href="http://docs.oracle.com/javase/tutorial/uiswing/components/menu.html">How to Use Menus</a>,
62 * a section in <em>The Java Tutorial.</em>
63 * <p>
64 * <strong>Warning:</strong> Swing is not thread safe. For more
65 * information see <a
66 * href="package-summary.html#threading">Swing's Threading
67 * Policy</a>.
68 * <p>
69 * <strong>Warning:</strong>
70 * Serialized objects of this class will not be compatible with
71 * future Swing releases. The current serialization support is
72 * appropriate for short term storage or RMI between applications running
73 * the same version of Swing. As of 1.4, support for long term storage
74 * of all JavaBeans™
75 * has been added to the <code>java.beans</code> package.
76 * Please see {@link java.beans.XMLEncoder}.
77 *
78 * @beaninfo
79 * attribute: isContainer false
80 * description: A component within a group of menu items which can be selected.
81 *
82 * @author Georges Saab
83 * @author David Karlton
84 * @see ButtonGroup
85 */
86 @SuppressWarnings("serial") // Same-version serialization only
87 public class JRadioButtonMenuItem extends JMenuItem implements Accessible {
88 /**
89 * @see #getUIClassID
90 * @see #readObject
91 */
92 private static final String uiClassID = "RadioButtonMenuItemUI";
93
94 /**
95 * Creates a <code>JRadioButtonMenuItem</code> with no set text or icon.
96 */
97 public JRadioButtonMenuItem() {
98 this(null, null, false);
99 }
100
101 /**
102 * Creates a <code>JRadioButtonMenuItem</code> with an icon.
103 *
104 * @param icon the <code>Icon</code> to display on the
105 * <code>JRadioButtonMenuItem</code>
106 */
107 public JRadioButtonMenuItem(Icon icon) {
108 this(null, icon, false);
109 }
110
111 /**
112 * Creates a <code>JRadioButtonMenuItem</code> with text.
113 *
114 * @param text the text of the <code>JRadioButtonMenuItem</code>
115 */
116 public JRadioButtonMenuItem(String text) {
117 this(text, null, false);
118 }
119
120 /**
121 * Creates a radio button menu item whose properties are taken from the
122 * <code>Action</code> supplied.
123 *
124 * @param a the <code>Action</code> on which to base the radio
125 * button menu item
126 *
127 * @since 1.3
128 */
129 public JRadioButtonMenuItem(Action a) {
130 this();
131 setAction(a);
132 }
133
134 /**
135 * Creates a radio button menu item with the specified text
136 * and <code>Icon</code>.
137 *
138 * @param text the text of the <code>JRadioButtonMenuItem</code>
139 * @param icon the icon to display on the <code>JRadioButtonMenuItem</code>
140 */
141 public JRadioButtonMenuItem(String text, Icon icon) {
142 this(text, icon, false);
143 }
144
145 /**
146 * Creates a radio button menu item with the specified text
147 * and selection state.
148 *
149 * @param text the text of the <code>CheckBoxMenuItem</code>
150 * @param selected the selected state of the <code>CheckBoxMenuItem</code>
151 */
152 public JRadioButtonMenuItem(String text, boolean selected) {
153 this(text);
154 setSelected(selected);
155 }
156
157 /**
158 * Creates a radio button menu item with the specified image
159 * and selection state, but no text.
160 *
161 * @param icon the image that the button should display
162 * @param selected if true, the button is initially selected;
163 * otherwise, the button is initially unselected
164 */
165 public JRadioButtonMenuItem(Icon icon, boolean selected) {
166 this(null, icon, selected);
167 }
168
169 /**
170 * Creates a radio button menu item that has the specified
171 * text, image, and selection state. All other constructors
172 * defer to this one.
173 *
174 * @param text the string displayed on the radio button
175 * @param icon the image that the button should display
176 */
177 public JRadioButtonMenuItem(String text, Icon icon, boolean selected) {
178 super(text, icon);
179 setModel(new JToggleButton.ToggleButtonModel());
180 setSelected(selected);
181 setFocusable(false);
182 }
183
184 /**
185 * Returns the name of the L&F class that renders this component.
186 *
187 * @return the string "RadioButtonMenuItemUI"
188 * @see JComponent#getUIClassID
189 * @see UIDefaults#getUI
190 */
191 public String getUIClassID() {
192 return uiClassID;
193 }
194
195 /**
196 * See <code>readObject</code> and <code>writeObject</code> in
197 * <code>JComponent</code> for more
198 * information about serialization in Swing.
199 */
200 private void writeObject(ObjectOutputStream s) throws IOException {
201 s.defaultWriteObject();
202 if (getUIClassID().equals(uiClassID)) {
203 byte count = JComponent.getWriteObjCounter(this);
204 JComponent.setWriteObjCounter(this, --count);
205 if (count == 0 && ui != null) {
206 ui.installUI(this);
207 }
208 }
209 }
210
211
212 /**
213 * Returns a string representation of this
214 * <code>JRadioButtonMenuItem</code>. This method
215 * is intended to be used only for debugging purposes, and the
216 * content and format of the returned string may vary between
217 * implementations. The returned string may be empty but may not
218 * be <code>null</code>.
219 *
220 * @return a string representation of this
221 * <code>JRadioButtonMenuItem</code>
222 */
223 protected String paramString() {
224 return super.paramString();
225 }
226
227 /**
228 * Overriden to return true, JRadioButtonMenuItem supports
229 * the selected state.
230 */
231 boolean shouldUpdateSelectedStateFromAction() {
232 return true;
233 }
234
235 /////////////////
236 // Accessibility support
237 ////////////////
238
239 /**
240 * Gets the AccessibleContext associated with this JRadioButtonMenuItem.
241 * For JRadioButtonMenuItems, the AccessibleContext takes the form of an
242 * AccessibleJRadioButtonMenuItem.
243 * A new AccessibleJRadioButtonMenuItem instance is created if necessary.
244 *
245 * @return an AccessibleJRadioButtonMenuItem that serves as the
246 * AccessibleContext of this JRadioButtonMenuItem
247 */
248 public AccessibleContext getAccessibleContext() {
249 if (accessibleContext == null) {
250 accessibleContext = new AccessibleJRadioButtonMenuItem();
251 }
252 return accessibleContext;
253 }
254
255 /**
256 * This class implements accessibility support for the
257 * <code>JRadioButtonMenuItem</code> class. It provides an
258 * implementation of the Java Accessibility API appropriate to
259 * <code>JRadioButtonMenuItem</code> user-interface elements.
260 * <p>
261 * <strong>Warning:</strong>
262 * Serialized objects of this class will not be compatible with
263 * future Swing releases. The current serialization support is
264 * appropriate for short term storage or RMI between applications running
265 * the same version of Swing. As of 1.4, support for long term storage
266 * of all JavaBeans™
267 * has been added to the <code>java.beans</code> package.
268 * Please see {@link java.beans.XMLEncoder}.
269 */
270 @SuppressWarnings("serial") // Same-version serialization only
271 protected class AccessibleJRadioButtonMenuItem extends AccessibleJMenuItem {
272 /**
273 * Get the role of this object.
274 *
275 * @return an instance of AccessibleRole describing the role of the
276 * object
277 */
278 public AccessibleRole getAccessibleRole() {
279 return AccessibleRole.RADIO_BUTTON;
280 }
281 } // inner class AccessibleJRadioButtonMenuItem
282 }