newlabel.java

《java事件处理指南》一书的代码,好东西

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

public class NewLabel extends JLabel implements PropertyChangeListener
{
   private FontColor fontColor;

   public NewLabel(String str, FontColor fc)
   {
      super(str);
      fontColor = fc;
      setForeground(fontColor.getColor());

/*  When a NewLabel object is created, its FontColor object       */
/*  registers a PropertyChangeListener.  When the Color           */
/*  object associated with the FontColor object is changed, the   */
/*  FontColor object will fire a PropertyChangeEvent that will    */
/*  be sent to this listener.                                     */

      fontColor.addPropertyChangeListener(this);
   }

   public FontColor getFontColor()
   {
      return fontColor;
   }

   public void setFontColor(FontColor fc)
   {
      fontColor = fc;
   }

/*  The NewLabel class serves as a PropertyChangeListener and thus  */
/*  provides an implementation of the propertyChange() method.  If  */
/*  the PropertyChangeEvent was due to a change in the "color"      */
/*  property, the text color of the NewLabel is changed.            */

   public void propertyChange(PropertyChangeEvent event)
   {
      if ( event.getPropertyName().equals("color") )
      {
         setForeground( (Color)event.getNewValue() );
      }
   }
}