Java Swing, 2nd Edition

The JCheckBox Class

The JCheckBox ^[5] class is shown in various L&Fs in Figure 5-7. JCheckBox is a subclass of JToggleButton and is typically used to allow the user to turn a given feature on or off or to make multiple selections from a set of choices. A JCheckBox is usually rendered by showing a small box into which a “check” is placed when selected (as shown in Figure 5-7). If you specify an icon for the checkbox, this icon replaces the default box. Therefore, if you specify an icon, you should always also supply a selected icon—otherwise, there is no way to tell if a checkbox is selected.

Figure 5-7. JCheckBoxes in four L&Fs

Properties

The JCheckBox class inherits most of its properties from its superclasses. The exceptions are shown in Table 5-12. By default, no border is painted on JCheckBoxes, and their horizontalAlignment is to the leading edge (which means to the left in the default locale, in which text reads left to right).^[6] Setting the borderPaintedFlat property to true is a hint to the L&F that the checkbox should be drawn more plainly than usual. (This is used primarily by cell renderers for tables and trees.)

Table 5-12. JCheckBox properties

Property	Data type	get	is	set	Default value
accessibleContexto	AccessibleContext	·			AccessibleJCheckBox
borderPaintedo	boolean		·	·	false
borderPaintedFlat1.3, b	boolean		·	·	false
horizontalAlignmento	int	·		·	LEADING1.4
UIClassIDo	String	·			“CheckBoxUI” ...