Java Reference
In-Depth Information
fontFaceDD.setMaximumRowCount(3);
sets the number of choices to be shown to 3. Because there are four choices in the combo
box fontFaceDD and only three choices are shown, a vertical scroll bar appears to the
right of the box. You can scroll this bar to see and select the other choices.
When you click an item in the combo box, it generates an item event. To process
item events, we use the interface ItemListener . As described in the previous
section,
the item event handler code is placed in the body of
the method
itemStateChanged .
When the user selects an item from a combo box, the index of the selected item can be
obtained by using the method getSelectedIndex() . For example, the statement:
currentFontName = fontNames[fontFaceDD.getSelectedIndex()];
assigns the current font name to the string variable currentFontName .
Example 12-7 gives the complete program listing for this JComboBox example.
EXAMPLE 12-7
//Welcome program with check boxes, radio buttons, and combo box
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class GrandWelcomeFinal extends JApplet implements
ItemListener
{
private int intBold = Font.PLAIN;
private int intItalic = Font.PLAIN;
private Color currentColor = Color.black;
private String currentFontName ="Courier";
private JCheckBox boldCB, italicCB;
private JRadioButton redRB, greenRB, blueRB;
private ButtonGroup ColorSelectBGroup;
private JComboBox fontFaceDD;
private String[] fontNames
= {"Dialog", "Century Gothic",
"Courier", "Serif"};
public void init()
{
Container c = getContentPane();
c.setLayout( null );
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