textcycler.java

在WEB页面循环显示一组信息。

/* TextCycler.java  
 *
 * Raven
 * [e-mail]
 * http://www.ravenmatrix.com 
 *
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details at http://www.gnu.org 
 */


import java.applet.*;
import java.awt.*;
import java.util.StringTokenizer;



public class TextCycler extends Applet implements Runnable {
Thread runner = null;    
Graphics cycle;
Image Item;
Font font;
int delay = 100;
String messages;
String CurrentMessage = "";
Dimension size;
FontMetrics a;



public void init() {
font = new Font("Courier", Font.PLAIN, 18);
messages= getParameter("messages");
size = size(); 
Item = createImage(size.width, size.height);
cycle =  Item.getGraphics();
a = cycle.getFontMetrics();
String param = getParameter("delay");
if (param != null) 
delay = Integer.valueOf(param).intValue();
}




public void start(){
if (runner == null)
{
runner = new Thread(this);
runner.start();
}
}




public void stop(){
if (runner != null)
{
runner.stop();
runner = null;
}
}




public void paint(Graphics g){
FontMetrics a = cycle.getFontMetrics();
cycle.setColor(Color.white);
cycle.fillRect(0,0,size.width,size.height);
cycle.setColor(Color.black);
cycle.setFont(font);
cycle.drawString(CurrentMessage, 
(size.width - a.stringWidth(CurrentMessage))/2,
size.height - a.getMaxDescent());
if (Item != null)
g.drawImage(Item, 0, 0, this);
}



public void run(){
StringTokenizer t = new StringTokenizer(messages, "|");
CurrentMessage = t.nextToken();    
while (true)
{
try
{                                   
if(t.hasMoreTokens())
{
CurrentMessage = t.nextToken();    
}
else
{
t = new StringTokenizer(messages, "|");
CurrentMessage = t.nextToken();    
}
repaint();
Thread.sleep(delay);
}
catch(InterruptedException e)
{
stop();
}
}
}
}