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 * @since 1.2 86 */ 87 @SuppressWarnings("serial") // Same-version serialization only 88 public class JRadioButtonMenuItem extends JMenuItem implements Accessible { 89 /** 90 * @see #getUIClassID 91 * @see #readObject 92 */ 93 private static final String uiClassID = "RadioButtonMenuItemUI"; 94 95 /** 96 * Creates a <code>JRadioButtonMenuItem</code> with no set text or icon. 97 */ 98 public JRadioButtonMenuItem() { 99 this(null, null, false); 100 } 101 102 /** 103 * Creates a <code>JRadioButtonMenuItem</code> with an icon. 104 * 105 * @param icon the <code>Icon</code> to display on the 106 * <code>JRadioButtonMenuItem</code> 107 */ 108 public JRadioButtonMenuItem(Icon icon) { 109 this(null, icon, false); 110 } 111 112 /** 113 * Creates a <code>JRadioButtonMenuItem</code> with text. 114 * 115 * @param text the text of the <code>JRadioButtonMenuItem</code> 116 */ 117 public JRadioButtonMenuItem(String text) { 118 this(text, null, false); 119 } 120 121 /** 122 * Creates a radio button menu item whose properties are taken from the 123 * <code>Action</code> supplied. 124 * 125 * @param a the <code>Action</code> on which to base the radio 126 * button menu item 127 * 128 * @since 1.3 129 */ 130 public JRadioButtonMenuItem(Action a) { 131 this(); 132 setAction(a); 133 } 134 135 /** 136 * Creates a radio button menu item with the specified text 137 * and <code>Icon</code>. 138 * 139 * @param text the text of the <code>JRadioButtonMenuItem</code> 140 * @param icon the icon to display on the <code>JRadioButtonMenuItem</code> 141 */ 142 public JRadioButtonMenuItem(String text, Icon icon) { 143 this(text, icon, false); 144 } 145 146 /** 147 * Creates a radio button menu item with the specified text 148 * and selection state. 149 * 150 * @param text the text of the <code>CheckBoxMenuItem</code> 151 * @param selected the selected state of the <code>CheckBoxMenuItem</code> 152 */ 153 public JRadioButtonMenuItem(String text, boolean selected) { 154 this(text); 155 setSelected(selected); 156 } 157 158 /** 159 * Creates a radio button menu item with the specified image 160 * and selection state, but no text. 161 * 162 * @param icon the image that the button should display 163 * @param selected if true, the button is initially selected; 164 * otherwise, the button is initially unselected 165 */ 166 public JRadioButtonMenuItem(Icon icon, boolean selected) { 167 this(null, icon, selected); 168 } 169 170 /** 171 * Creates a radio button menu item that has the specified 172 * text, image, and selection state. All other constructors 173 * defer to this one. 174 * 175 * @param text the string displayed on the radio button 176 * @param icon the image that the button should display 177 * @param selected if {@code true}, the button is initially selected, 178 * otherwise, the button is initially unselected 179 */ 180 public JRadioButtonMenuItem(String text, Icon icon, boolean selected) { 181 super(text, icon); 182 setModel(new JToggleButton.ToggleButtonModel()); 183 setSelected(selected); 184 setFocusable(false); 185 } 186 187 /** 188 * Returns the name of the L&F class that renders this component. 189 * 190 * @return the string "RadioButtonMenuItemUI" 191 * @see JComponent#getUIClassID 192 * @see UIDefaults#getUI 193 */ 194 public String getUIClassID() { 195 return uiClassID; 196 } 197 198 /** 199 * See <code>readObject</code> and <code>writeObject</code> in 200 * <code>JComponent</code> for more 201 * information about serialization in Swing. 202 */ 203 private void writeObject(ObjectOutputStream s) throws IOException { 204 s.defaultWriteObject(); 205 if (getUIClassID().equals(uiClassID)) { 206 byte count = JComponent.getWriteObjCounter(this); 207 JComponent.setWriteObjCounter(this, --count); 208 if (count == 0 && ui != null) { 209 ui.installUI(this); 210 } 211 } 212 } 213 214 215 /** 216 * Returns a string representation of this 217 * <code>JRadioButtonMenuItem</code>. This method 218 * is intended to be used only for debugging purposes, and the 219 * content and format of the returned string may vary between 220 * implementations. The returned string may be empty but may not 221 * be <code>null</code>. 222 * 223 * @return a string representation of this 224 * <code>JRadioButtonMenuItem</code> 225 */ 226 protected String paramString() { 227 return super.paramString(); 228 } 229 230 /** 231 * Overriden to return true, JRadioButtonMenuItem supports 232 * the selected state. 233 */ 234 boolean shouldUpdateSelectedStateFromAction() { 235 return true; 236 } 237 238 ///////////////// 239 // Accessibility support 240 //////////////// 241 242 /** 243 * Gets the AccessibleContext associated with this JRadioButtonMenuItem. 244 * For JRadioButtonMenuItems, the AccessibleContext takes the form of an 245 * AccessibleJRadioButtonMenuItem. 246 * A new AccessibleJRadioButtonMenuItem instance is created if necessary. 247 * 248 * @return an AccessibleJRadioButtonMenuItem that serves as the 249 * AccessibleContext of this JRadioButtonMenuItem 250 */ 251 public AccessibleContext getAccessibleContext() { 252 if (accessibleContext == null) { 253 accessibleContext = new AccessibleJRadioButtonMenuItem(); 254 } 255 return accessibleContext; 256 } 257 258 /** 259 * This class implements accessibility support for the 260 * <code>JRadioButtonMenuItem</code> class. It provides an 261 * implementation of the Java Accessibility API appropriate to 262 * <code>JRadioButtonMenuItem</code> user-interface elements. 263 * <p> 264 * <strong>Warning:</strong> 265 * Serialized objects of this class will not be compatible with 266 * future Swing releases. The current serialization support is 267 * appropriate for short term storage or RMI between applications running 268 * the same version of Swing. As of 1.4, support for long term storage 269 * of all JavaBeans™ 270 * has been added to the <code>java.beans</code> package. 271 * Please see {@link java.beans.XMLEncoder}. 272 */ 273 @SuppressWarnings("serial") // Same-version serialization only 274 protected class AccessibleJRadioButtonMenuItem extends AccessibleJMenuItem { 275 /** 276 * Get the role of this object. 277 * 278 * @return an instance of AccessibleRole describing the role of the 279 * object 280 */ 281 public AccessibleRole getAccessibleRole() { 282 return AccessibleRole.RADIO_BUTTON; 283 } 284 } // inner class AccessibleJRadioButtonMenuItem 285 }