Java Swing, 2nd Edition

The JRadioButton Class

JRadioButton is a subclass of JToggleButton, typically used with other JRadioButtons, that allows users to make a single selection from a set of options (Figure 5-8). Because radio buttons form a set of choices, JRadioButtons are usually used in groups, managed by a ButtonGroup (described in the next section). If you specify an icon for the radio button, you should also specify a selected icon so it will be visually apparent if a button is selected.

Figure 5-8. JRadioButtons in four L&Fs

Properties

The JRadioButton class inherits all its properties and most of its default values from its superclass. The only exceptions are shown in Table 5-14. By default, no border is painted on JRadioButtons, and their horizontalAlignment is set to the leading edge (to the left in the default locale, in which text reads left to right).^[7]

Table 5-14. JRadioButton properties

Property	Data type	get	is	set	Default value
accessibleContexto	AccessibleContext	·			JRadioButton.AccessibleJRadioButton( )
borderPaintedo	boolean		·	·	false
horizontalAlignmento	int	·		·	LEADING1.4
UIClassIDo	String	·			“RadioButtonUI”
1.4since 1.4, ooverridden See also properties from JToggleButton (Table 5-10).

Events

See the discussion of JToggleButton (JRadioButton’s superclass) events.

Constructors

public JRadioButton( )

Create a button that has no text or icon and is not selected.

public JRadioButton(Action a)

Create a ...