Java Reference
In-Depth Information
constants TOP , CENTER , or BOTTOM , as shown in Figure 12.21. The default vertical text posi-
tion is AbstractButton.CENTER .
Text positioned top
Text centered
vertically
Text positioned bottom
F IGURE 12.21
You can specify the vertical position of the text relative to the icon.
12.28 How do you create a button with the text OK? How do you change text on a button?
How do you set an icon, a pressed icon, and a rollover icon in a button?
12.29 Given a JButton object jbtOK , write statements to set the button's foreground to
red , background to yellow , mnemonic to K , tool tip text to Click OK to pro-
ceed , horizontal alignment to RIGHT , vertical alignment to BOTTOM , horizontal text
position to LEFT , vertical text position to TOP , and icon text gap to 5 .
12.30 List at least five properties defined in the AbstractButton class.
Check
Point
12.12 JCheckBox
To create a check box button, use the JCheckBox class.
Key
Point
toggle button
A toggle button is a two-state button like a light switch. JToggleButton inherits
AbstractButton and implements a toggle button. Often JToggleButton 's subclasses
JCheckBox and JRadioButton are used to enable the user to toggle a choice on or off. This
section introduces JCheckBox . JRadioButton will be introduced in the next section.
JCheckBox inherits all the properties from AbstractButton , such as text , icon ,
mnemonic , verticalAlignment , horizontalAlignment , horizontalTextPosition ,
verticalTextPosition , and selected , and provides several constructors to create check
boxes, as shown in Figure 12.22.
javax.swing.AbstractButton
javax.swing.JToggleButton
javax.swing.JCheckBox
+JCheckBox()
+JCheckBox(text: String)
+JCheckBox(text: String, selected:
boolean)
+JCheckBox(icon: Icon)
+JCheckBox(text: String, icon: Icon)
+JCheckBox(text: String, icon: Icon,
selected: boolean)
Creates a default check box without any text or icon.
Creates a check box with text.
Creates a check box with text and specifies whether the check box is
initially selected.
Creates a check box with an icon.
Creates a check box with text and an icon.
Creates a check box with text and an icon, and specifies whether the check
box is initially selected.
F IGURE 12.22
JCheckBox defines a check box button.
 
 
 
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