mylabel.java

java编程源代码

/*001*/import java.util.*;
/*002*/import java.awt.*;
/*003*/import java.awt.event.*;
/*004*/
/*005*/public class myLabel extends Label 
/*006*/						implements TextChangeable {
/*007*/	private   Vector   listeners     = new Vector();
/*008*/
/*009*/	public myLabel(String str) {
/*010*/		super(str);
/*011*/	}
/*012*/	public void addTextListener(myTextListener l) {
/*013*/		listeners.addElement(l);
/*014*/	}
/*015*/	public void removeTextListener(myTextListener l) {
/*016*/		listeners.removeElement(l);
/*017*/	}
/*018*/	public void setText(String str)
/*019*/	{
/*020*/		String str_old=this.getText();
/*021*/		super.setText(str);
/*022*/		if(str_old==null) str_old="";
/*023*/		TextChangeEvent event=new TextChangeEvent(this,str_old,str);
/*024*/		if(!str_old.equals(str));
/*025*/		{
/*026*/			Enumeration e = listeners.elements();
/*027*/			while(e.hasMoreElements()) {
/*028*/			myTextListener l = (myTextListener)
/*029*/									e.nextElement();
/*030*/			l.textChanged(event);
/*031*/			}
/*032*/		}
/*033*/	}
/*034*/}