complete14_5.java

来自「程序练习中包括书中实例程序代码和练习中要用到的代码,是压缩文件」· Java 代码 · 共 37 行

package questions.c14;
import javax.swing.*;
import java.awt.*;
public class Complete14_5 extends JApplet
                          implements Runnable {
   public void init() {
      getContentPane().add( new OvalPanel(),
                            BorderLayout.CENTER );
      setSize( 450, 450 );
   }
   public void start() {
      // your code here
   }
   public void stop() {
      // your code here
   }
   public void run() {
      // your code here
   }
   public class OvalPanel extends JPanel {
      private final int MAX_DIAM = 150;
      private int diameter = 10;
      public void paintComponent( Graphics g ) {
         super.paintComponent( g );
         // erase by drawing in the background color
         g.setColor( getBackground() );
         g.fillOval( 200, 200, diameter, diameter );
         // draw the new shape
         g.setColor( Color.blue );
         diameter += 10;
         if ( diameter > MAX_DIAM ) {
            diameter = 10;
         }
         g.fillOval( 200, 200, diameter, diameter );
      }
   }
}