complete13_5.java

北京大学出版社的

package questions.c13;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Vector;
import java.util.Enumeration;
public class Complete13_5 extends JFrame {
   private Vector singleClicks = new Vector();
   private Vector doubleClicks = new Vector();
   public Complete13_5( String titleText ) {
      super( titleText );
      addWindowListener( new WindowAdapter() {
            public void windowClosing( WindowEvent e ) {
               e.getWindow().dispose();
               System.exit( 0 );
            }
         }
      );

      // add your mouse handler here

      getContentPane().add( new ClickPanel(),
                            BorderLayout.CENTER );
      setSize( 500, 300 );
      setVisible( true );
   }
   public class ClickPanel extends JPanel {
      public void paintComponent( Graphics g ) {
         super.paintComponent( g );
         final int dotRadius = 5;
         // show single clicks by drawing blue dots
         Enumeration e = singleClicks.elements();
         g.setColor( Color.blue );
         while ( e.hasMoreElements() ) {
            Point p = (Point) e.nextElement();
            g.fillOval( p.x - dotRadius, p.y - dotRadius,
                        dotRadius * 2, dotRadius * 2 );
         }
         // show double clicks by drawing green dots
         e = doubleClicks.elements();
         g.setColor( Color.green );
         while ( e.hasMoreElements() ) {
            Point p = (Point) e.nextElement();
            g.fillOval( p.x - dotRadius, p.y - dotRadius,
                        dotRadius * 2, dotRadius * 2 );
         }
      }
   }
   public static void main( String[] args ) {
      new Complete13_5( "Complete the Solution" );
   }
}