fancytext.java

Java Applet实例编程.rar

import java.awt.*;
import java.applet.*;


public class FancyText extends Applet implements Runnable {

  String s = null;
  int direct = 1;
  int Hrad = 12;
  int Vrad = 12;
  Thread thread = null;
  char words[];
  int phase = 0;
  Image offI;
  Graphics offG;
  Color colors[];
  private Font f;
  private FontMetrics fm;



   public void init() {
   
     String param = null;
     s = getParameter("word");
     setBackground(Color.black);
     
     words =  new char [s.length()];
     s.getChars(0,s.length(),words,0);
     offI = createImage(getSize().width,getSize().height);
     offG = offI.getGraphics();

     f = new Font("TimesRoman",Font.BOLD,36);
     fm=getFontMetrics(f);
     
     offG.setFont(f);

     
     float h;
     colors = new Color[s.length()];
     for (int i = 0; i < s.length(); i++) {
        h = ((float)i)/((float)s.length());
        colors[i] = new Color(Color.HSBtoRGB(h,1.0f,1.0f));
     }

   }



   public void start() {

     if(thread == null) {
       thread = new Thread(this);
       thread.start();
     }
   }


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

   public void run() {
      while (thread != null) {
         try {
            Thread.sleep(200);
         }catch (InterruptedException e) { }

	 repaint();
      }

   }


   public void update(Graphics g) {
      int x, y;
      double ang;

      offG.setColor(Color.black);
      offG.fillRect(0,0,getSize().width,getSize().height);
      phase+=direct;
      phase%=8;
      for(int i=0;i<s.length();i++) {
         ang = ((phase-i*direct)%8)/4.0*Math.PI;
         x = 20+fm.getMaxAdvance()*i+(int) (Math.cos(ang)*Hrad);
         y = 60+  (int) (Math.sin(ang)*Vrad);
         offG.setColor(colors[(phase+i)%s.length()]);
         offG.drawChars(words,i,1,x,y);
      }

      paint(g);

   }



  public void paint(Graphics g) {

    g.drawImage(offI,0,0,this);

  }

}