// Fig. 12.11: CheckBoxTest.java

// Creating Checkbox buttons.

// Java core packages

import java.awt.*;

import java.awt.event.*;

// Java extension packages

import javax.swing.*;

public class CheckBoxTest extends JFrame {

private JTextField field;

private JCheckBox bold, italic;

// set up GUI

public CheckBoxTest()

{

super( "JCheckBox Test" );

// get content pane and set its layout

Container container = getContentPane();

container.setLayout( new FlowLayout() );

// set up JTextField and set its font

field =

new JTextField( "Watch the font style change", 20 );

field.setFont( new Font( "Serif", Font.PLAIN, 14 ) );

container.add( field );

// create checkbox objects

bold = new JCheckBox( "Bold" );

container.add( bold );

italic = new JCheckBox( "Italic" );

container.add( italic );

// register listeners for JCheckBoxes

CheckBoxHandler handler = new CheckBoxHandler();

bold.addItemListener( handler );

italic.addItemListener( handler );

setSize( 275, 100 );

setVisible( true );

}

// execute application

public static void main( String args[] )

{

CheckBoxTest application = new CheckBoxTest();

application.addWindowListener(new WindowAdapter()

{ public void windowClosing( WindowEvent event )

{

System.exit( 0 );

}

}

);

}

// private inner class for ItemListener event handling

private class CheckBoxHandler implements ItemListener {

private int valBold = Font.PLAIN;

private int valItalic = Font.PLAIN;

// respond to checkbox events

public void itemStateChanged( ItemEvent event )

{

// process bold checkbox events

if ( event.getSource() == bold )

if ( event.getStateChange() == ItemEvent.SELECTED )

valBold = Font.BOLD;

else

valBold = Font.PLAIN;

// process italic checkbox events

if ( event.getSource() == italic )

if ( event.getStateChange() == ItemEvent.SELECTED )

valItalic = Font.ITALIC;

else

valItalic = Font.PLAIN;

// set text field font

field.setFont(

new Font( "Serif", valBold + valItalic, 14 ) );

}

} // end private inner class CheckBoxHandler

} // end class CheckBoxTest