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 JavaBeansTM
* 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
*/
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
*/
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 JavaBeansTM
* has been added to the java.beans package.
* Please see {@link java.beans.XMLEncoder}.
*/
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
}