// Fig. 13.8: PopupTest.java // Demonstrating JPopupMenus import javax.swing.*; import java.awt.event.*; import java.awt.*; public class PopupTest extends JFrame { private JRadioButtonMenuItem items[]; private Color colorValues[] = { Color.blue, Color.yellow, Color.red }; public PopupTest() { super( "Using JPopupMenus" ); final JPopupMenu popupMenu = new JPopupMenu(); ItemHandler handler = new ItemHandler(); String colors[] = { "Blue", "Yellow", "Red" }; ButtonGroup colorGroup = new ButtonGroup(); items = new JRadioButtonMenuItem[ 3 ]; // construct each menu item and add to popup menu; also // enable event handling for each menu item for ( int i = 0; i < items.length; i++ ) { items[ i ] = new JRadioButtonMenuItem( colors[ i ] ); popupMenu.add( items[ i ] ); colorGroup.add( items[ i ] ); items[ i ].addActionListener( handler ); } getContentPane().setBackground( Color.white ); // define a MouseListener for the window that displays // a JPopupMenu when the popup trigger event occurs addMouseListener( new MouseAdapter() { public void mousePressed( MouseEvent e ) { checkForTriggerEvent( e ); } public void mouseReleased( MouseEvent e ) { checkForTriggerEvent( e ); } private void checkForTriggerEvent( MouseEvent e ) { if ( e.isPopupTrigger() ) popupMenu.show( e.getComponent(), e.getX(), e.getY() ); } } ); setSize( 300, 200 ); show(); } public static void main( String args[] ) { PopupTest app = new PopupTest(); app.addWindowListener( new WindowAdapter() { public void windowClosing( WindowEvent e ) { System.exit( 0 ); } } ); } private class ItemHandler implements ActionListener { public void actionPerformed( ActionEvent e ) { // determine which menu item was selected for ( int i = 0; i < items.length; i++ ) if ( e.getSource() == items[ i ] ) { getContentPane().setBackground( colorValues[ i ] ); repaint(); return; } } } } /************************************************************************** * (C) Copyright 1999 by Deitel & Associates, Inc. and Prentice Hall. * * All Rights Reserved. * * * * DISCLAIMER: The authors and publisher of this book have used their * * best efforts in preparing the book. These efforts include the * * development, research, and testing of the theories and programs * * to determine their effectiveness. The authors and publisher make * * no warranty of any kind, expressed or implied, with regard to these * * programs or to the documentation contained in these books. The authors * * and publisher shall not be liable in any event for incidental or * * consequential damages in connection with, or arising out of, the * * furnishing, performance, or use of these programs. * *************************************************************************/