1 /* 2 * Copyright (c) 1997, 2013, 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="https://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="https://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 public class JRadioButtonMenuItem extends JMenuItem implements Accessible { 87 /** 88 * @see #getUIClassID 89 * @see #readObject 90 */ 91 private static final String uiClassID = "RadioButtonMenuItemUI"; 92 93 /** 94 * Creates a <code>JRadioButtonMenuItem</code> with no set text or icon. 95 */ 96 public JRadioButtonMenuItem() { 97 this(null, null, false); 98 } 99 100 /** 101 * Creates a <code>JRadioButtonMenuItem</code> with an icon. 102 * 103 * @param icon the <code>Icon</code> to display on the 104 * <code>JRadioButtonMenuItem</code> 105 */ 106 public JRadioButtonMenuItem(Icon icon) { 107 this(null, icon, false); 108 } 109 110 /** 111 * Creates a <code>JRadioButtonMenuItem</code> with text. 112 * 113 * @param text the text of the <code>JRadioButtonMenuItem</code> 114 */ 115 public JRadioButtonMenuItem(String text) { 116 this(text, null, false); 117 } 118 119 /** 120 * Creates a radio button menu item whose properties are taken from the 121 * <code>Action</code> supplied. 122 * 123 * @param a the <code>Action</code> on which to base the radio 124 * button menu item 125 * 126 * @since 1.3 127 */ 128 public JRadioButtonMenuItem(Action a) { 129 this(); 130 setAction(a); 131 } 132 133 /** 134 * Creates a radio button menu item with the specified text 135 * and <code>Icon</code>. 136 * 137 * @param text the text of the <code>JRadioButtonMenuItem</code> 138 * @param icon the icon to display on the <code>JRadioButtonMenuItem</code> 139 */ 140 public JRadioButtonMenuItem(String text, Icon icon) { 141 this(text, icon, false); 142 } 143 144 /** 145 * Creates a radio button menu item with the specified text 146 * and selection state. 147 * 148 * @param text the text of the <code>CheckBoxMenuItem</code> 149 * @param selected the selected state of the <code>CheckBoxMenuItem</code> 150 */ 151 public JRadioButtonMenuItem(String text, boolean selected) { 152 this(text); 153 setSelected(selected); 154 } 155 156 /** 157 * Creates a radio button menu item with the specified image 158 * and selection state, but no text. 159 * 160 * @param icon the image that the button should display 161 * @param selected if true, the button is initially selected; 162 * otherwise, the button is initially unselected 163 */ 164 public JRadioButtonMenuItem(Icon icon, boolean selected) { 165 this(null, icon, selected); 166 } 167 168 /** 169 * Creates a radio button menu item that has the specified 170 * text, image, and selection state. All other constructors 171 * defer to this one. 172 * 173 * @param text the string displayed on the radio button 174 * @param icon the image that the button should display 175 */ 176 public JRadioButtonMenuItem(String text, Icon icon, boolean selected) { 177 super(text, icon); 178 setModel(new JToggleButton.ToggleButtonModel()); 179 setSelected(selected); 180 setFocusable(false); 181 } 182 183 /** 184 * Returns the name of the L&F class that renders this component. 185 * 186 * @return the string "RadioButtonMenuItemUI" 187 * @see JComponent#getUIClassID 188 * @see UIDefaults#getUI 189 */ 190 public String getUIClassID() { 191 return uiClassID; 192 } 193 194 /** 195 * See <code>readObject</code> and <code>writeObject</code> in 196 * <code>JComponent</code> for more 197 * information about serialization in Swing. 198 */ 199 private void writeObject(ObjectOutputStream s) throws IOException { 200 s.defaultWriteObject(); 201 if (getUIClassID().equals(uiClassID)) { 202 byte count = JComponent.getWriteObjCounter(this); 203 JComponent.setWriteObjCounter(this, --count); 204 if (count == 0 && ui != null) { 205 ui.installUI(this); 206 } 207 } 208 } 209 210 211 /** 212 * Returns a string representation of this 213 * <code>JRadioButtonMenuItem</code>. This method 214 * is intended to be used only for debugging purposes, and the 215 * content and format of the returned string may vary between 216 * implementations. The returned string may be empty but may not 217 * be <code>null</code>. 218 * 219 * @return a string representation of this 220 * <code>JRadioButtonMenuItem</code> 221 */ 222 protected String paramString() { 223 return super.paramString(); 224 } 225 226 /** 227 * Overriden to return true, JRadioButtonMenuItem supports 228 * the selected state. 229 */ 230 boolean shouldUpdateSelectedStateFromAction() { 231 return true; 232 } 233 234 ///////////////// 235 // Accessibility support 236 //////////////// 237 238 /** 239 * Gets the AccessibleContext associated with this JRadioButtonMenuItem. 240 * For JRadioButtonMenuItems, the AccessibleContext takes the form of an 241 * AccessibleJRadioButtonMenuItem. 242 * A new AccessibleJRadioButtonMenuItem instance is created if necessary. 243 * 244 * @return an AccessibleJRadioButtonMenuItem that serves as the 245 * AccessibleContext of this JRadioButtonMenuItem 246 */ 247 public AccessibleContext getAccessibleContext() { 248 if (accessibleContext == null) { 249 accessibleContext = new AccessibleJRadioButtonMenuItem(); 250 } 251 return accessibleContext; 252 } 253 254 /** 255 * This class implements accessibility support for the 256 * <code>JRadioButtonMenuItem</code> class. It provides an 257 * implementation of the Java Accessibility API appropriate to 258 * <code>JRadioButtonMenuItem</code> user-interface elements. 259 * <p> 260 * <strong>Warning:</strong> 261 * Serialized objects of this class will not be compatible with 262 * future Swing releases. The current serialization support is 263 * appropriate for short term storage or RMI between applications running 264 * the same version of Swing. As of 1.4, support for long term storage 265 * of all JavaBeans™ 266 * has been added to the <code>java.beans</code> package. 267 * Please see {@link java.beans.XMLEncoder}. 268 */ 269 protected class AccessibleJRadioButtonMenuItem extends AccessibleJMenuItem { 270 /** 271 * Get the role of this object. 272 * 273 * @return an instance of AccessibleRole describing the role of the 274 * object 275 */ 276 public AccessibleRole getAccessibleRole() { 277 return AccessibleRole.RADIO_BUTTON; 278 } 279 } // inner class AccessibleJRadioButtonMenuItem 280 }