Java Platform 1.2

Class ButtonGroup


public class ButtonGroup
extends Object
implements Serializable

This class is used to create a multiple-exclusion scope for a set of buttons. Creating a set of buttons with the same ButtonGroup object means that turning "on" one of those buttons turns off all other buttons in the group. A ButtonGroup can be used with sets of JButton, JRadioButton, or JRadioButtonMenuItem objects.

Initially, all buttons in the group are unselected. Once any button is selected, one button is always selected in the group. There is no way to turn a button programmatically to "off", in order to clear the button group. To give the appearance of "none selected", add an invisible radio button to the group and then programmatically select that button to turn off all the displayed radio buttons. For example, a normal button with the label "none" could be wired to select the invisible radio button.

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. A future release of Swing will provide support for long term persistence.

See Also:
Serialized Form

Field Summary
protected  Vector buttons
Constructor Summary
          Creates a new ButtonGroup.
Method Summary
 void add(AbstractButton b)
          Adds the button to the group.
 Enumeration getElements()
          Return all the buttons that are participating in this group.
 ButtonModel getSelection()
          Return the selected button model.
 boolean isSelected(ButtonModel m)
          Returns the selected value for the button.
 void remove(AbstractButton b)
          Removes the button from the group.
 void setSelected(ButtonModel m, boolean b)
          Sets the selected value for the button.
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail


protected Vector buttons
Constructor Detail


public ButtonGroup()
Creates a new ButtonGroup.
Method Detail


public void add(AbstractButton b)
Adds the button to the group.


public void remove(AbstractButton b)
Removes the button from the group.


public Enumeration getElements()
Return all the buttons that are participating in this group.


public ButtonModel getSelection()
Return the selected button model.


public void setSelected(ButtonModel m,
                        boolean b)
Sets the selected value for the button.


public boolean isSelected(ButtonModel m)
Returns the selected value for the button.

Java Platform 1.2

Submit a bug or feature Version 1.2 of Java Platform API Specification
Java is a trademark or registered trademark of Sun Microsystems, Inc. in the US and other countries.
Copyright 1993-1998 Sun Microsystems, Inc. 901 San Antonio Road,
Palo Alto, California, 94303, U.S.A. All Rights Reserved.