Module java.desktop
Package javax.swing

Class ButtonGroup

java.lang.Object
javax.swing.ButtonGroup
All Implemented Interfaces:
Serializable
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 any set of objects that inherit from AbstractButton. Typically a button group contains instances of JRadioButton, JRadioButtonMenuItem, or JToggleButton. It wouldn't make sense to put an instance of JButton or JMenuItem in a button group because JButton and JMenuItem don't implement the selected state.

Initially, all buttons in the group are unselected.

For examples and further information on using button groups see How to Use Radio Buttons, a section in The Java Tutorial.

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 XMLEncoder.

Since:
1.2

  • Field Details

    • buttons

      protected Vector<AbstractButton> buttons
      The list of buttons participating in this group.

  • Constructor Details

    • ButtonGroup

      public ButtonGroup()
      Creates a new ButtonGroup.

  • Method Details

    • add

      public void add(AbstractButton b)
      Adds the button to the group.
      Parameters:
      b - the button to be added

    • remove

      public void remove(AbstractButton b)
      Removes the button from the group.
      Parameters:
      b - the button to be removed

    • clearSelection

      public void clearSelection()
      Clears the selection such that none of the buttons in the ButtonGroup are selected.
      Since:
      1.6

    • getElements

      public Enumeration<AbstractButton> getElements()
      Returns all the buttons that are participating in this group.
      Returns:
      an Enumeration of the buttons in this group

    • getSelection

      public ButtonModel getSelection()
      Returns the model of the selected button.
      Returns:
      the selected button model

    • setSelected

      public void setSelected(ButtonModel m, boolean b)
      Sets the selected value for the ButtonModel. Only one button in the group may be selected at a time.
      Parameters:
      m - the ButtonModel
      b - true if this button is to be selected, otherwise false

    • isSelected

      public boolean isSelected(ButtonModel m)
      Returns whether a ButtonModel is selected.
      Parameters:
      m - an instance of ButtonModel
      Returns:
      true if the button is selected, otherwise returns false

    • getButtonCount

      public int getButtonCount()
      Returns the number of buttons in the group.
      Returns:
      the button count
      Since:
      1.3