JRadioButtonMenuItem is
+ * a menu item that is part of a group of menu items in which only one
+ * item in the group can be selected. The selected item displays its
+ * selected state. Selecting it causes any other selected item to
+ * switch to the unselected state.
+ * To control the selected state of a group of radio button menu items,
+ * use a ButtonGroup object.
+ *
+ * Menu items can be configured, and to some degree controlled, by
+ * Actions. Using an
+ * Action with a menu item has many benefits beyond directly
+ * configuring a menu item. Refer to
+ * Swing Components Supporting Action for more
+ * details, and you can find more information in How
+ * to Use Actions, a section in The Java Tutorial.
+ *
+ * For further documentation and examples see + * How to Use Menus, + * a section in The Java Tutorial. + *
+ * Warning: Swing is not thread safe. For more + * information see Swing's Threading + * Policy. + *
+ * Warning:
+ * Serialized objects of this class will not be compatible with
+ * future Swing releases. The current serialization support is
+ * appropriate for short term storage or RMI between applications running
+ * the same version of Swing. As of 1.4, support for long term storage
+ * of all JavaBeans™
+ * has been added to the java.beans package.
+ * Please see {@link java.beans.XMLEncoder}.
+ *
+ * @beaninfo
+ * attribute: isContainer false
+ * description: A component within a group of menu items which can be selected.
+ *
+ * @author Georges Saab
+ * @author David Karlton
+ * @see ButtonGroup
+ * @since 1.2
+ */
+@SuppressWarnings("serial") // Same-version serialization only
+public class JRadioButtonMenuItem extends JMenuItem implements Accessible {
+ /**
+ * @see #getUIClassID
+ * @see #readObject
+ */
+ private static final String uiClassID = "RadioButtonMenuItemUI";
+
+ /**
+ * Creates a JRadioButtonMenuItem with no set text or icon.
+ */
+ public JRadioButtonMenuItem() {
+ this(null, null, false);
+ }
+
+ /**
+ * Creates a JRadioButtonMenuItem with an icon.
+ *
+ * @param icon the Icon to display on the
+ * JRadioButtonMenuItem
+ */
+ public JRadioButtonMenuItem(Icon icon) {
+ this(null, icon, false);
+ }
+
+ /**
+ * Creates a JRadioButtonMenuItem with text.
+ *
+ * @param text the text of the JRadioButtonMenuItem
+ */
+ public JRadioButtonMenuItem(String text) {
+ this(text, null, false);
+ }
+
+ /**
+ * Creates a radio button menu item whose properties are taken from the
+ * Action supplied.
+ *
+ * @param a the Action on which to base the radio
+ * button menu item
+ *
+ * @since 1.3
+ */
+ public JRadioButtonMenuItem(Action a) {
+ this();
+ setAction(a);
+ }
+
+ /**
+ * Creates a radio button menu item with the specified text
+ * and Icon.
+ *
+ * @param text the text of the JRadioButtonMenuItem
+ * @param icon the icon to display on the JRadioButtonMenuItem
+ */
+ public JRadioButtonMenuItem(String text, Icon icon) {
+ this(text, icon, false);
+ }
+
+ /**
+ * Creates a radio button menu item with the specified text
+ * and selection state.
+ *
+ * @param text the text of the CheckBoxMenuItem
+ * @param selected the selected state of the CheckBoxMenuItem
+ */
+ public JRadioButtonMenuItem(String text, boolean selected) {
+ this(text);
+ setSelected(selected);
+ }
+
+ /**
+ * Creates a radio button menu item with the specified image
+ * and selection state, but no text.
+ *
+ * @param icon the image that the button should display
+ * @param selected if true, the button is initially selected;
+ * otherwise, the button is initially unselected
+ */
+ public JRadioButtonMenuItem(Icon icon, boolean selected) {
+ this(null, icon, selected);
+ }
+
+ /**
+ * Creates a radio button menu item that has the specified
+ * text, image, and selection state. All other constructors
+ * defer to this one.
+ *
+ * @param text the string displayed on the radio button
+ * @param icon the image that the button should display
+ * @param selected if {@code true}, the button is initially selected,
+ * otherwise, the button is initially unselected
+ */
+ public JRadioButtonMenuItem(String text, Icon icon, boolean selected) {
+ super(text, icon);
+ setModel(new JToggleButton.ToggleButtonModel());
+ setSelected(selected);
+ setFocusable(false);
+ }
+
+ /**
+ * Returns the name of the L&F class that renders this component.
+ *
+ * @return the string "RadioButtonMenuItemUI"
+ * @see JComponent#getUIClassID
+ * @see UIDefaults#getUI
+ */
+ public String getUIClassID() {
+ return uiClassID;
+ }
+
+ /**
+ * See readObject and writeObject in
+ * JComponent for more
+ * information about serialization in Swing.
+ */
+ private void writeObject(ObjectOutputStream s) throws IOException {
+ s.defaultWriteObject();
+ if (getUIClassID().equals(uiClassID)) {
+ byte count = JComponent.getWriteObjCounter(this);
+ JComponent.setWriteObjCounter(this, --count);
+ if (count == 0 && ui != null) {
+ ui.installUI(this);
+ }
+ }
+ }
+
+
+ /**
+ * Returns a string representation of this
+ * JRadioButtonMenuItem. This method
+ * is intended to be used only for debugging purposes, and the
+ * content and format of the returned string may vary between
+ * implementations. The returned string may be empty but may not
+ * be null.
+ *
+ * @return a string representation of this
+ * JRadioButtonMenuItem
+ */
+ protected String paramString() {
+ return super.paramString();
+ }
+
+ /**
+ * Overriden to return true, JRadioButtonMenuItem supports
+ * the selected state.
+ */
+ boolean shouldUpdateSelectedStateFromAction() {
+ return true;
+ }
+
+/////////////////
+// Accessibility support
+////////////////
+
+ /**
+ * Gets the AccessibleContext associated with this JRadioButtonMenuItem.
+ * For JRadioButtonMenuItems, the AccessibleContext takes the form of an
+ * AccessibleJRadioButtonMenuItem.
+ * A new AccessibleJRadioButtonMenuItem instance is created if necessary.
+ *
+ * @return an AccessibleJRadioButtonMenuItem that serves as the
+ * AccessibleContext of this JRadioButtonMenuItem
+ */
+ public AccessibleContext getAccessibleContext() {
+ if (accessibleContext == null) {
+ accessibleContext = new AccessibleJRadioButtonMenuItem();
+ }
+ return accessibleContext;
+ }
+
+ /**
+ * This class implements accessibility support for the
+ * JRadioButtonMenuItem class. It provides an
+ * implementation of the Java Accessibility API appropriate to
+ * JRadioButtonMenuItem user-interface elements.
+ *
+ * Warning:
+ * Serialized objects of this class will not be compatible with
+ * future Swing releases. The current serialization support is
+ * appropriate for short term storage or RMI between applications running
+ * the same version of Swing. As of 1.4, support for long term storage
+ * of all JavaBeans™
+ * has been added to the java.beans package.
+ * Please see {@link java.beans.XMLEncoder}.
+ */
+ @SuppressWarnings("serial") // Same-version serialization only
+ protected class AccessibleJRadioButtonMenuItem extends AccessibleJMenuItem {
+ /**
+ * Get the role of this object.
+ *
+ * @return an instance of AccessibleRole describing the role of the
+ * object
+ */
+ public AccessibleRole getAccessibleRole() {
+ return AccessibleRole.RADIO_BUTTON;
+ }
+ } // inner class AccessibleJRadioButtonMenuItem
+}