package popup;
// Fig. 14.10: PopupTest.java
// Demonstrating JPopupMenus
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class PopupTest extends JFrame {
   private JRadioButtonMenuItem items[];
   private final Color colorValues[] = 
      { Color.BLUE, Color.YELLOW, Color.RED };
   private JPopupMenu popupMenu;

   // set up GUI
   public PopupTest()
   {
      super( "Using JPopupMenus" );

      ItemHandler handler = new ItemHandler();
      String colors[] = { "Blue", "Yellow", "Red" };

      // set up popup menu and its items
      ButtonGroup colorGroup = new ButtonGroup();
      popupMenu = new JPopupMenu();
      items = new JRadioButtonMenuItem[ 3 ];

      // construct each menu item and add to popup menu; also
      // enable event handling for each menu item
      for ( int count = 0; count < items.length; count++ ) {
         items[ count ] = new JRadioButtonMenuItem( colors[ count ] );
         popupMenu.add( items[ count ] );
         colorGroup.add( items[ count ] );
         items[ count ].addActionListener( handler );
      }

      getContentPane().setBackground( Color.WHITE );

      // declare a MouseListener for the window that displays
      // a JPopupMenu when the popup trigger event occurs
      addMouseListener(

         new MouseAdapter() {  // anonymous inner class

            // handle mouse press event
            public void mousePressed( MouseEvent event )
            { 
               checkForTriggerEvent( event ); 
            } 

            // handle mouse release event
            public void mouseReleased( MouseEvent event )
            { 
               checkForTriggerEvent( event ); 
            } 

            // determine whether event should trigger popup menu
            private void checkForTriggerEvent( MouseEvent event )
            {
               if ( event.isPopupTrigger() ) 
                  popupMenu.show( 
                     event.getComponent(), event.getX(), event.getY() );  
            }

         } // end anonymous inner clas

      ); // end call to addMouseListener

      setSize( 300, 200 );
      setVisible( true );

   } // end constructor PopupTest

   public static void main( String args[] )
   {
      PopupTest application = new PopupTest();
      application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
   }

   // private inner class to handle menu item events
   private class ItemHandler implements ActionListener {

      // process menu item selections
      public void actionPerformed( ActionEvent event )
      {
         // determine which menu item was selected
         for ( int i = 0; i < items.length; i++ )
            if ( event.getSource() == items[ i ] ) {
               getContentPane().setBackground( colorValues[ i ] );
               return;
            }
      }

   } // end private inner class ItemHandler

} // end class PopupTest

