/***********************************************
 * Applet that your homework will be based off of
 **********************************************/

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

public class Blink extends java.applet.Applet implements Runnable {
  // the animation thread
  Thread blinkThread;
  // the text to blink
  String blinkingtext;
  // the text font
  Font font;
  // the speed of the blinking in miliseconds
  int speed;

  // set up the applet to run
  public void init() {
    font = new Font("TimesRoman", Font.PLAIN, 24);
    speed = 400;
    blinkingtext = "This is a simple blinking text applet for demonstration in SE 450"; 
  }
  
  
  public void paint(Graphics g) {
    // the variables for the location of the string
    // the y gets set to the height of the font
    int x = 0, y = font.getSize(), space;
    
    // randomly determine what the color is going to be
    int red = (int)(Math.random() * 50);
    int green = (int)(Math.random() * 50);
    int blue = (int)(Math.random() * 256);
    
    // the size of the applet region
    Dimension d = getSize();
    
    g.setColor(Color.black);
    g.setFont(font);
    
    // the font metrics object is used to get information
    // about the current font
    FontMetrics fm = g.getFontMetrics();
    // determine how wide a blank space is in this font.
    space = fm.stringWidth(" ");
    
    // the StringTokenizer will break up the text for the applet
    // up into individual words.
    // the "for" loop processes each individual word
    for (StringTokenizer t = new StringTokenizer(blinkingtext); 
	 t.hasMoreTokens() ; ) {
      // the current word that you are working with
      String word = t.nextToken();
      
      // add the length of a space to the length of the word
      int w = fm.stringWidth(word) + space;
      
      // this checks to see if the word + the space will fit on the 
      // current line.
      // if not, it moves the word to the next line.
      // if it will fit then it just adds it on.
    
      if (x + w > d.width) {
	x = 0;
	y += font.getSize();
      }
      // this is how you get the words to dissapear.
      // if the random is less than .5 the word gets
      // drawn in the color.
      // if it's not, then the word gets drawn in the 
      // background color, and seems to disappear
      if (Math.random() < 0.5) {
	g.setColor(new Color((red + y * 30) % 256, 
			     (green + x / 3) % 256, 
			     blue));
      } else {
	g.setColor(getBackground());
      }
      // actually draw the word on the screen
      g.drawString(word, x, y);
      // move the "cursor" over in preparation for the next word.
      x += w;
    }
  }
  
  // start the animation thread up
  public void start() {
    blinkThread = new Thread(this);
    blinkThread.start();
  }
  
  // stop the animation thread
  public void stop() {
    blinkThread = null;
  }
  
  // periodically make the applet repaing.
  // this is what causes the blinking effect.
  public void run() {
    while (Thread.currentThread() == blinkThread) {
      repaint();
      try { 
	Thread.currentThread().sleep(speed); 
      } 
      catch (InterruptedException e){}
    }
  }
}