J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2006 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | package javax.swing; |
| 26 | |
| 27 | import java.awt.*; |
| 28 | import java.awt.event.*; |
| 29 | import java.beans.*; |
| 30 | |
| 31 | import javax.swing.plaf.*; |
| 32 | import javax.accessibility.*; |
| 33 | |
| 34 | import java.io.ObjectOutputStream; |
| 35 | import java.io.ObjectInputStream; |
| 36 | import java.io.IOException; |
| 37 | |
| 38 | |
| 39 | /** |
| 40 | * An implementation of a radio button -- an item that can be selected or |
| 41 | * deselected, and which displays its state to the user. |
| 42 | * Used with a {@link ButtonGroup} object to create a group of buttons |
| 43 | * in which only one button at a time can be selected. (Create a ButtonGroup |
| 44 | * object and use its <code>add</code> method to include the JRadioButton objects |
| 45 | * in the group.) |
| 46 | * <blockquote> |
| 47 | * <strong>Note:</strong> |
| 48 | * The ButtonGroup object is a logical grouping -- not a physical grouping. |
| 49 | * To create a button panel, you should still create a {@link JPanel} or similar |
| 50 | * container-object and add a {@link javax.swing.border.Border} to it to set it off from surrounding |
| 51 | * components. |
| 52 | * </blockquote> |
| 53 | * <p> |
| 54 | * Buttons can be configured, and to some degree controlled, by |
| 55 | * <code><a href="Action.html">Action</a></code>s. Using an |
| 56 | * <code>Action</code> with a button has many benefits beyond directly |
| 57 | * configuring a button. Refer to <a href="Action.html#buttonActions"> |
| 58 | * Swing Components Supporting <code>Action</code></a> for more |
| 59 | * details, and you can find more information in <a |
| 60 | * href="http://java.sun.com/docs/books/tutorial/uiswing/misc/action.html">How |
| 61 | * to Use Actions</a>, a section in <em>The Java Tutorial</em>. |
| 62 | * <p> |
| 63 | * See <a href="http://java.sun.com/docs/books/tutorial/uiswing/components/button.html">How to Use Buttons, Check Boxes, and Radio Buttons</a> |
| 64 | * in <em>The Java Tutorial</em> |
| 65 | * for further documentation. |
| 66 | * <p> |
| 67 | * <strong>Warning:</strong> Swing is not thread safe. For more |
| 68 | * information see <a |
| 69 | * href="package-summary.html#threading">Swing's Threading |
| 70 | * Policy</a>. |
| 71 | * <p> |
| 72 | * <strong>Warning:</strong> |
| 73 | * Serialized objects of this class will not be compatible with |
| 74 | * future Swing releases. The current serialization support is |
| 75 | * appropriate for short term storage or RMI between applications running |
| 76 | * the same version of Swing. As of 1.4, support for long term storage |
| 77 | * of all JavaBeans<sup><font size="-2">TM</font></sup> |
| 78 | * has been added to the <code>java.beans</code> package. |
| 79 | * Please see {@link java.beans.XMLEncoder}. |
| 80 | * |
| 81 | * @beaninfo |
| 82 | * attribute: isContainer false |
| 83 | * description: A component which can display it's state as selected or deselected. |
| 84 | * |
| 85 | * @see ButtonGroup |
| 86 | * @see JCheckBox |
| 87 | * @author Jeff Dinkins |
| 88 | */ |
| 89 | public class JRadioButton extends JToggleButton implements Accessible { |
| 90 | |
| 91 | /** |
| 92 | * @see #getUIClassID |
| 93 | * @see #readObject |
| 94 | */ |
| 95 | private static final String uiClassID = "RadioButtonUI"; |
| 96 | |
| 97 | |
| 98 | /** |
| 99 | * Creates an initially unselected radio button |
| 100 | * with no set text. |
| 101 | */ |
| 102 | public JRadioButton () { |
| 103 | this(null, null, false); |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * Creates an initially unselected radio button |
| 108 | * with the specified image but no text. |
| 109 | * |
| 110 | * @param icon the image that the button should display |
| 111 | */ |
| 112 | public JRadioButton(Icon icon) { |
| 113 | this(null, icon, false); |
| 114 | } |
| 115 | |
| 116 | /** |
| 117 | * Creates a radiobutton where properties are taken from the |
| 118 | * Action supplied. |
| 119 | * |
| 120 | * @since 1.3 |
| 121 | */ |
| 122 | public JRadioButton(Action a) { |
| 123 | this(); |
| 124 | setAction(a); |
| 125 | } |
| 126 | |
| 127 | /** |
| 128 | * Creates a radio button with the specified image |
| 129 | * and selection state, but no text. |
| 130 | * |
| 131 | * @param icon the image that the button should display |
| 132 | * @param selected if true, the button is initially selected; |
| 133 | * otherwise, the button is initially unselected |
| 134 | */ |
| 135 | public JRadioButton(Icon icon, boolean selected) { |
| 136 | this(null, icon, selected); |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * Creates an unselected radio button with the specified text. |
| 141 | * |
| 142 | * @param text the string displayed on the radio button |
| 143 | */ |
| 144 | public JRadioButton (String text) { |
| 145 | this(text, null, false); |
| 146 | } |
| 147 | |
| 148 | /** |
| 149 | * Creates a radio button with the specified text |
| 150 | * and selection state. |
| 151 | * |
| 152 | * @param text the string displayed on the radio button |
| 153 | * @param selected if true, the button is initially selected; |
| 154 | * otherwise, the button is initially unselected |
| 155 | */ |
| 156 | public JRadioButton (String text, boolean selected) { |
| 157 | this(text, null, selected); |
| 158 | } |
| 159 | |
| 160 | /** |
| 161 | * Creates a radio button that has the specified text and image, |
| 162 | * and that is initially unselected. |
| 163 | * |
| 164 | * @param text the string displayed on the radio button |
| 165 | * @param icon the image that the button should display |
| 166 | */ |
| 167 | public JRadioButton(String text, Icon icon) { |
| 168 | this(text, icon, false); |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * Creates a radio button that has the specified text, image, |
| 173 | * and selection state. |
| 174 | * |
| 175 | * @param text the string displayed on the radio button |
| 176 | * @param icon the image that the button should display |
| 177 | */ |
| 178 | public JRadioButton (String text, Icon icon, boolean selected) { |
| 179 | super(text, icon, selected); |
| 180 | setBorderPainted(false); |
| 181 | setHorizontalAlignment(LEADING); |
| 182 | } |
| 183 | |
| 184 | |
| 185 | /** |
| 186 | * Resets the UI property to a value from the current look and feel. |
| 187 | * |
| 188 | * @see JComponent#updateUI |
| 189 | */ |
| 190 | public void updateUI() { |
| 191 | setUI((ButtonUI)UIManager.getUI(this)); |
| 192 | } |
| 193 | |
| 194 | |
| 195 | /** |
| 196 | * Returns the name of the L&F class |
| 197 | * that renders this component. |
| 198 | * |
| 199 | * @return String "RadioButtonUI" |
| 200 | * @see JComponent#getUIClassID |
| 201 | * @see UIDefaults#getUI |
| 202 | * @beaninfo |
| 203 | * expert: true |
| 204 | * description: A string that specifies the name of the L&F class. |
| 205 | */ |
| 206 | public String getUIClassID() { |
| 207 | return uiClassID; |
| 208 | } |
| 209 | |
| 210 | |
| 211 | /** |
| 212 | * The icon for radio buttons comes from the look and feel, |
| 213 | * not the Action. |
| 214 | */ |
| 215 | void setIconFromAction(Action a) { |
| 216 | } |
| 217 | |
| 218 | /** |
| 219 | * See readObject() and writeObject() in JComponent for more |
| 220 | * information about serialization in Swing. |
| 221 | */ |
| 222 | private void writeObject(ObjectOutputStream s) throws IOException { |
| 223 | s.defaultWriteObject(); |
| 224 | if (getUIClassID().equals(uiClassID)) { |
| 225 | byte count = JComponent.getWriteObjCounter(this); |
| 226 | JComponent.setWriteObjCounter(this, --count); |
| 227 | if (count == 0 && ui != null) { |
| 228 | ui.installUI(this); |
| 229 | } |
| 230 | } |
| 231 | } |
| 232 | |
| 233 | |
| 234 | /** |
| 235 | * Returns a string representation of this JRadioButton. This method |
| 236 | * is intended to be used only for debugging purposes, and the |
| 237 | * content and format of the returned string may vary between |
| 238 | * implementations. The returned string may be empty but may not |
| 239 | * be <code>null</code>. |
| 240 | * |
| 241 | * @return a string representation of this JRadioButton. |
| 242 | */ |
| 243 | protected String paramString() { |
| 244 | return super.paramString(); |
| 245 | } |
| 246 | |
| 247 | |
| 248 | ///////////////// |
| 249 | // Accessibility support |
| 250 | //////////////// |
| 251 | |
| 252 | |
| 253 | /** |
| 254 | * Gets the AccessibleContext associated with this JRadioButton. |
| 255 | * For JRadioButtons, the AccessibleContext takes the form of an |
| 256 | * AccessibleJRadioButton. |
| 257 | * A new AccessibleJRadioButton instance is created if necessary. |
| 258 | * |
| 259 | * @return an AccessibleJRadioButton that serves as the |
| 260 | * AccessibleContext of this JRadioButton |
| 261 | * @beaninfo |
| 262 | * expert: true |
| 263 | * description: The AccessibleContext associated with this Button |
| 264 | */ |
| 265 | public AccessibleContext getAccessibleContext() { |
| 266 | if (accessibleContext == null) { |
| 267 | accessibleContext = new AccessibleJRadioButton(); |
| 268 | } |
| 269 | return accessibleContext; |
| 270 | } |
| 271 | |
| 272 | /** |
| 273 | * This class implements accessibility support for the |
| 274 | * <code>JRadioButton</code> class. It provides an implementation of the |
| 275 | * Java Accessibility API appropriate to radio button |
| 276 | * user-interface elements. |
| 277 | * <p> |
| 278 | * <strong>Warning:</strong> |
| 279 | * Serialized objects of this class will not be compatible with |
| 280 | * future Swing releases. The current serialization support is |
| 281 | * appropriate for short term storage or RMI between applications running |
| 282 | * the same version of Swing. As of 1.4, support for long term storage |
| 283 | * of all JavaBeans<sup><font size="-2">TM</font></sup> |
| 284 | * has been added to the <code>java.beans</code> package. |
| 285 | * Please see {@link java.beans.XMLEncoder}. |
| 286 | */ |
| 287 | protected class AccessibleJRadioButton extends AccessibleJToggleButton { |
| 288 | |
| 289 | /** |
| 290 | * Get the role of this object. |
| 291 | * |
| 292 | * @return an instance of AccessibleRole describing the role of the object |
| 293 | * @see AccessibleRole |
| 294 | */ |
| 295 | public AccessibleRole getAccessibleRole() { |
| 296 | return AccessibleRole.RADIO_BUTTON; |
| 297 | } |
| 298 | |
| 299 | } // inner class AccessibleJRadioButton |
| 300 | } |