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

/**********************************************************
 * Grading:
 * 2 two points for determining that the state change operations
 * had to go into either start or stop
 * 2 points for getting the color to change on each visit
 * 2 points for getting the text to change on each visit
 * 2 points for getting the font face to change on each visit
 * 2 points for getting the speed to change on each visit
 **********************************************************/  

public class BlinkHW extends java.applet.Applet implements Runnable {
  Thread blinkThread;
  String currentBlinkingText;
  // to store the three messages
  String [] possibleTexts = new String[3];
  // the RGB components of the color
  int red, green, blue;

  // flags to keep track of the state
  boolean isPlain;
  boolean isFast;
  boolean isFirstStart;

  // the current text that we are looking at
  int currentTextIndex;

  Font font;
  int speed;

  public void init() {
    // initial font
    font = new Font("TimesRoman", Font.PLAIN, 24);
    isPlain = true;

    // initial speed
    speed = 1000;
    isFast = false;

    // initialize the possible messages
    possibleTexts[0] = "Hello world!!";
    possibleTexts[1] = "SE450 is great.";
    possibleTexts[2] = "This is a simple blinking text applet for demonstration in SE 450"; 

    // initialize the current text
    currentBlinkingText = possibleTexts[0];
    currentTextIndex = 0;

    // initialize the starting colors
    red = (int)(Math.random() * 256);
    green = (int)(Math.random() * 256);
    blue = (int)(Math.random() * 256);

    // flag to tell you this is the first start
    isFirstStart = true;

  }
    
  public void paint(Graphics g) {
    int x = 0, y = font.getSize(), space;
    Dimension d = getSize();
    
    g.setColor(Color.black);
    g.setFont(font);
    FontMetrics fm = g.getFontMetrics();
    space = fm.stringWidth(" ");
    StringTokenizer t = new StringTokenizer(currentBlinkingText);
    while (t.hasMoreTokens()) {
      String word = t.nextToken();
      int w = fm.stringWidth(word) + space;
      if (x + w > d.width) {
	   x = 0;
	   y += font.getSize();
      }
      // this gives you the missing words
      if (Math.random() < 0.5) {
	   g.setColor(new Color(red, green, blue));
      }
      else {
	   g.setColor(getBackground());
      }

      g.drawString(word, x, y);
      x += w;
    }
  }

  public void start() {
    // do this on subsequent starts other than the first one
    if (! isFirstStart){
       // change the color of the text
       red = (int)(Math.random() * 256);
       green = (int)(Math.random() * 256);
       blue = (int)(Math.random() * 256);
       //System.out.println("Red =" + red);
	 //System.out.println("Green =" + green);
 	 //System.out.println("Blue =" + blue);


       // change the speed
	 if (isFast){ // slow the speed down
	    speed = (int)(speed - 1000 * Math.random()); 
       }
       else{ // speed it up
          speed = (int)(speed + 1000 * Math.random()); 
       }
       isFast = !isFast;
       //System.out.println("Speed = " + speed);

       // change the font face
       if (isPlain){ // make it italic
	    font = new Font("TimesRoman", Font.ITALIC, 24);
       }
       else{ // make it plain
          font = new Font("TimesRoman", Font.PLAIN, 24);
       }
       isPlain = !isPlain;

       // change the message
       if (currentTextIndex == (possibleTexts.length - 1)){ 
   	    // you need to go back to 0 because there is no index 3.
          currentTextIndex = 0;
	    
       }
       else{ // increment the index
          currentTextIndex++;
       }
	 currentBlinkingText = possibleTexts[currentTextIndex];


    }
    else{  // do this on the first start
        isFirstStart = false;
    }

    // start up the thread
    blinkThread = new Thread(this);
    blinkThread.start();
  }
  
  public void stop() {
    // kill the thread
    blinkThread = null;
  }
  
  public void run() {
    while (Thread.currentThread() == blinkThread) {
      repaint();
      try { 
	   Thread.currentThread().sleep(speed); 
      } 
      catch (InterruptedException e){}
    }
  }
}