imageviewerbean.java

java的五个源代码

/**
 * @version 1.20 1999-09-24
 * @author Cay Horstmann
 */

import java.awt.*;
import java.io.*;
import javax.swing.*;

public class ImageViewerBean extends JPanel
   implements Serializable
{  public void setFileName(String f)
   {  fileName = f;
      image = Toolkit.getDefaultToolkit().getImage(fileName);
      MediaTracker tracker = new MediaTracker(this);
      tracker.addImage(image, 0);
      try { tracker.waitForID(0); }
      catch (InterruptedException e) {}
      repaint();
   }

   public String getFileName()
   {  return fileName;
   }

   public void paint(Graphics g)
   {  if (image == null)
      {  g.drawRect(0, 0, getWidth() - 1, getHeight() - 1);
      }
      else
         g.drawImage(image, 0, 0, this);
   }

   public Dimension getPreferredSize()
   {  if (image == null)
         return new Dimension(MINSIZE, MINSIZE);
      return new Dimension(image.getWidth(null),
         image.getHeight(null));
   }

   private static final int MINSIZE = 50;
   private Image image = null;
   private String fileName = "";
}