areatest.java

这个是我老师给的关于Java核心技术2的第7章的源代码

/**
   @version 1.02 2004-08-24
   @author Cay Horstmann
*/

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;

/**
   This program demonstrates constructive area geometry 
   operations.
*/
public class AreaTest
{  
   public static void main(String[] args)
   {  
      JFrame frame = new AreaTestFrame();
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.setVisible(true);
   }
}

/**
   This frame contains a set of radio buttons to define
   area operations and a panel to show their result.
*/
class AreaTestFrame extends JFrame
{  
   public AreaTestFrame()
   {  
      setTitle("AreaTest");
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

      area1 = new Area(new Ellipse2D.Double(100, 100, 150, 100));
      area2 = new Area(new Rectangle2D.Double(150, 150, 150, 100));

      panel = new 
         JPanel()
         {
            public void paintComponent(Graphics g)
            {  
               super.paintComponent(g);
               Graphics2D g2 = (Graphics2D)g;
               g2.draw(area1);
               g2.draw(area2);
               if (area != null) g2.fill(area);
            }
         };

      add(panel, BorderLayout.CENTER);

      JPanel buttonPanel = new JPanel();
      ButtonGroup group = new ButtonGroup();

      JRadioButton addButton = new JRadioButton("Add", false);
      buttonPanel.add(addButton);
      group.add(addButton);
      addButton.addActionListener(new 
         ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               area = new Area();
               area.add(area1);
               area.add(area2);
               panel.repaint();
            }
         });

      JRadioButton subtractButton = new JRadioButton("Subtract", false);
      buttonPanel.add(subtractButton);
      group.add(subtractButton);
      subtractButton.addActionListener(new 
         ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               area = new Area();
               area.add(area1);
               area.subtract(area2);
               panel.repaint();
            }
         });

      JRadioButton intersectButton = new JRadioButton("Intersect", false);
      buttonPanel.add(intersectButton);
      group.add(intersectButton);
      intersectButton.addActionListener(new 
         ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               area = new Area();
               area.add(area1);
               area.intersect(area2);
               panel.repaint();
            }
         });

      JRadioButton exclusiveOrButton = new JRadioButton("Exclusive Or", false);
      buttonPanel.add(exclusiveOrButton);
      group.add(exclusiveOrButton);
      exclusiveOrButton.addActionListener(new 
         ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               area = new Area();
               area.add(area1);
               area.exclusiveOr(area2);
               panel.repaint();
            }
         });

      add(buttonPanel, BorderLayout.NORTH);
   }

   private JPanel panel;
   private Area area;
   private Area area1;
   private Area area2;

   private static final int DEFAULT_WIDTH = 400;
   private static final int DEFAULT_HEIGHT = 400;
}