/** Use JWS to modify MyApplet14.java (previously AnimatorApplet6.java) by adding 
 ** another, fourth, "Lost in Space?" scenario. Your scenario should include a 
 ** different background image choosen from the Astronomy Picture of the Day Archive 
 ** at: http://antwrp.gsfc.nasa.gov/apod/archivepix.html. In addition, you should 
 ** include a rocketship image moving in a different way with a different scrolling 
 ** text. After your scenario completes, it should loop smoothly back to the first 
 ** scenario. Also, edit MyApplet14.html in the project directory, both to run the
 ** MyApplet14.class file you create, and so that everything looks nice and works 
 ** properly.                                                                     **/

/** USE EXISTING JAVA CLASSES **/

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

/** EXTEND THE JAVA APPLET CLASS AND IMPLEMENT THE RUNNABLE INTERFACE **/

public class MyApplet14 extends Applet implements Runnable
   {int frameNumber = -1;                
    int delay;                          
    Thread animatorThread;
    boolean frozen = false;
    Font waitfont=new Font("TimesRoman",Font.BOLD,14);
    FontMetrics waitfontm = getFontMetrics(waitfont);
    String waitstr1, waitstr2 = "";
    Font shipfont=new Font("TimesRoman",Font.PLAIN,14);
    FontMetrics shipfontm = getFontMetrics(shipfont);
    String shipstr = "";
    String shipstrpad = "                                                    ";
    Font titlefont=new Font("TimesRoman",Font.BOLD,24);
    FontMetrics titlefontm = getFontMetrics(titlefont);
    String titlestr = "";
    Color starblue = new Color(0,100,255);
    Dimension preImageDim;               // Define preImage variables needed to
    Image preImage;                      // create the offscreen copy of the image
    Graphics preImageGraphics;           // we want to paint on the screen.

    Image backgroundstarImage[];                    
    Image AndromedaImage;
    Image MilkywayHydrogenImage;
    Image PleiadesClusterImage;
    Image borgcubeImage;                 // Not currently being used.
    Image rocketshipImage;
    Image DeathStarImage;
    MediaTracker tracker;                
    int backNumber = 0;
    int shipstrIndex = 0;
    int xspeedUp = 0;
    int yspeedUp = 0;

    /** INITIALIZE THE APPLET **/

    public void init()
       {setBackground(Color.black);
	String str;
        int fps = 10;                      // Define the default fps (frames per second).
        str = getParameter("fps");         // Possibly, get HTML string specifying the
        try                                // fps.
         {if (str != null)
           {fps = Integer.parseInt(str);}  // If possible, convert HTML fps to an
          }                                // integer.
        catch (Exception e) {}             // In case the try caused something strange.
        delay = (fps > 0) ? (1000/fps): 100; // Convert fps to the milisecond delay
                                             // time between frames.			     
	backgroundstarImage = new Image[4];
        tracker = new MediaTracker(this);    // Spawn the tracker background thread(s)
	AndromedaImage = getImage(getCodeBase(),"images/asteriod.jpg");
	tracker.addImage(AndromedaImage,0);
	MilkywayHydrogenImage = getImage(getCodeBase(),"images/starfield.gif");
	tracker.addImage(MilkywayHydrogenImage,0);
	PleiadesClusterImage = getImage(getCodeBase(),"images/tiescout.gif");
	tracker.addImage(PleiadesClusterImage,0);
	DeathStarImage = getImage(getCodeBase(),"images/dstar1.jpg");
	tracker.addImage(DeathStarImage,0);

	
	backgroundstarImage[0] = AndromedaImage;
	tracker.addImage(backgroundstarImage[0],0);
	backgroundstarImage[1] = MilkywayHydrogenImage;
	tracker.addImage(backgroundstarImage[1],0);
	backgroundstarImage[2] = PleiadesClusterImage;
	tracker.addImage(backgroundstarImage[2],0);
	backgroundstarImage[3] = DeathStarImage;
	tracker.addImage(backgroundstarImage[3],0);
	
	//borgcubeImage = getImage(getCodeBase(),"images/borgcube.jpg");
	//tracker.addImage(borgcubeImage,0);
	rocketshipImage = getImage(getCodeBase(),"images/mfalcon2.gif");
	tracker.addImage(rocketshipImage,0);
	}  

    /** CLICK TO START OR STOP THE APPLET **/

    public boolean mouseDown(Event e, int x, int y)
       {if (frozen)
         {frozen = false;
          start();}
        else
         {frozen = true;
          animatorThread = null;           // Instead of calling stop() here, since
	  }                                // stop() now nullifies our preImage context,
        return true;                       // nullify only the animation thread in case
        }                                  // we want to build on our current preImage.

    /** GENERATE AND/OR START THE ANIMATION THREAD **/

    public void start()
       {if (frozen) { }                    // The animation is supposed to stay frozen.
        else                               // Otherwise, generate and/or start the
         {if (animatorThread == null)      // animation thread. Apparently, if run
           {animatorThread = new Thread(this);}  // breaks after catching an exception,
          animatorThread.start();                // the animatorThread though not null
          }                                      // will still need to be restarted.
        }

    /** CREATE AND DISPLAY FRAMES OF THE ANIMATION THREAD **/

    public void run()
       {try                                              // Start loading the images and
	 {tracker.waitForAll();}                         // wait until done before starting   
        catch (InterruptedException e) {}                // the animation.
        Thread.currentThread().setPriority(Thread.MIN_PRIORITY); // Set the priority low.
        long startTime = System.currentTimeMillis();             // Remember start time.
        while (Thread.currentThread() == animatorThread)         // The animation loop.
           {frameNumber++;                               // Advance the frame number.
            repaint();                                   // Display the frame.
            try                                          // Sleep for the delay period.
             {startTime += delay;
              Thread.sleep(Math.max(0,
                                    startTime-System.currentTimeMillis()));
              }
            catch (InterruptedException e) {break;}     // In case the try caused
            }                                           // something strange, exit
        }                                               // the while loop.


    /** CREATE THE CURRENT FRAME OF THE ANIMATION THREAD **/
    
    public void paint(Graphics g)         // This technique of painting by calling
     {if (!frozen) update(g);}            // update, prevents the default (and hidden)  
					  // behavior of update, and instead allows
    public void update(Graphics g)        // the creation of an offscreen preImage 
     {Dimension d = size();              // preImage before painting the screen.  
      if (!tracker.checkAll())                       // If the images aren't all
       {g.clearRect(0, 0, d.width, d.height);        // loaded, then clear the 
	g.setColor(starblue);
	g.setFont(waitfont);  
	waitstr1 = "Loading images, please wait...  Depending upon your computer ";
	waitstr2 = "and/or your connection speed, this may take several minutes...";
	g.drawString(waitstr1,                                    
	             (d.width - waitfontm.stringWidth(waitstr1))/2, 
		      d.height/2);                                
        g.drawString(waitstr2,                                    
	             (d.width - waitfontm.stringWidth(waitstr2))/2, 
		      (d.height/2) + waitfontm.getHeight());                                
	}
      else	       	               
       {if ((preImageGraphics == null) ||               // When all images are loaded, 
	    (d.width != preImageDim.width) ||           // compare the current applet
	    (d.height != preImageDim.height))           // viewing size to our preImage,
	     {preImageDim = d;                          // and if different, resize our 
	      preImage = createImage(d.width,d.height); // next preImage.
	      preImageGraphics = preImage.getGraphics();
	      }                                     
	preImageGraphics.setColor(getBackground());      // Clear the previous preImage
	preImageGraphics.fillRect(0,0,d.width,d.height); // by filling with the current
							 // background.
	int rocketshipWidth = rocketshipImage.getWidth(this);   // Get rocketship image 
	int rocketshipHeight = rocketshipImage.getHeight(this); // dimensions.    
	int xscrollDistance = d.width + rocketshipWidth;                         
	int yscrollDistance = d.height + rocketshipHeight;  
	int xscrollPosition = 0;
	int yscrollPosition = 0;
    
	preImageGraphics.drawImage(                          
	   backgroundstarImage[backNumber],              // Select background image.     
	   0,0,d.width,d.height,Color.black,this);       // Position and size image,     
							 // and set background color.
	preImageGraphics.setFont(titlefont);                  
	preImageGraphics.setColor(Color.white);  
	preImageGraphics.drawString(
	 "May the Force Be With You",
	  d.width - titlefontm.stringWidth("May the Force Be With You "),
	   d.height - titlefontm.getAscent());
	if (backNumber == 0)
	  preImageGraphics.drawString(
	   "What a pathetic asteroid field  ",
	   d.width - titlefontm.stringWidth("What a pathetic asteroid field  "),
	   titlefontm.getAscent());
	else if (backNumber == 1)
	  preImageGraphics.drawString(
	   "What The ?! ",
	   d.width - titlefontm.stringWidth("What The ?! "),
	   titlefontm.getAscent());
	else if (backNumber == 2)
	  preImageGraphics.drawString(
	   "This could be trouble ",
	   d.width - titlefontm.stringWidth("This could be trouble "),
	   titlefontm.getAscent());
	else if (backNumber == 3)
	  preImageGraphics.drawString(
	   "This could be trouble ",
	   d.width - titlefontm.stringWidth("This could be trouble "),
	   titlefontm.getAscent());

	if (backNumber == 0)                                   // Paint on background 0.
	  {yscrollPosition = (frameNumber % yscrollDistance) - rocketshipHeight;
	   if (yscrollPosition >= d.height/2) xspeedUp++;      // Go to warp speed.
	   xscrollPosition = 
	      (frameNumber % xscrollDistance) - rocketshipWidth + xspeedUp*50;
	   preImageGraphics.drawImage(
	      rocketshipImage,
	      xscrollPosition,
	      yscrollPosition,this);	
	   preImageGraphics.setFont(shipfont);
	   shipstr = "              We've come out of hyperspace right into an asteroid field!!";
	   shipstr += shipstrpad + shipstrpad + shipstrpad + shipstrpad + shipstrpad;                  // Pad shipstr with blanks.
	   if (yscrollPosition > 0)
	    {preImageGraphics.drawString(
	     shipstr.substring(shipstrIndex,shipstrIndex + 11), // Compute current substring
	     xscrollPosition + 65,                              // of shipstr to display.
	     yscrollPosition + rocketshipWidth/2);	
	     if (frameNumber % 2 == 0) shipstrIndex++;          // Slow down shipstr display.
	     if (shipstrIndex + 11 == shipstr.length()) shipstrIndex = 0; // Start over at 
	     }	                                                          // end of shipstr.
	   if (xscrollPosition >= d.width)                      // Setup for next background.
	    {frameNumber = -1; 
	     backNumber = 1;
	     shipstrIndex = 0;
	     xspeedUp = 0;
	     }
	   }
	else if (backNumber == 1)                               // Paint on background 1.
	 {yscrollPosition = 3*(d.height/4) - (frameNumber % yscrollDistance);
	  if (yscrollPosition <= .1*d.height) xspeedUp++;
	  xscrollPosition = 
	        (frameNumber % xscrollDistance) - rocketshipWidth + xspeedUp*50;
	  preImageGraphics.drawImage(
	      rocketshipImage,
	      xscrollPosition,
	      yscrollPosition,this);	
	  preImageGraphics.setFont(shipfont);
	  shipstr = "		These are the coordinates for Aldderran, but.. It's not here ?!";
	  shipstr += shipstrpad + shipstrpad;
	  if (yscrollPosition < .62*d.height)
	   {preImageGraphics.drawString(
	    shipstr.substring(shipstrIndex,shipstrIndex + 11),
	    xscrollPosition + 80,
	    yscrollPosition + rocketshipWidth/2);	
	    if (frameNumber % 2 == 0) shipstrIndex++;
	    if (shipstrIndex + 11 == shipstr.length()) shipstrIndex = 0; 
	    }	
	  if (xscrollPosition >= d.width)                      // Setup for next background. 
	   {frameNumber = -1; 
	    backNumber = 2;
	    shipstrIndex = 0;
	    xspeedUp = 0;
	    } 
	  } 
	else if (backNumber == 2)                               // Paint on background 2.
	 {xscrollPosition = 
	        (frameNumber % xscrollDistance) - rocketshipWidth + xspeedUp*50;
	  yscrollPosition = d.height/2 + yspeedUp*30;
	  preImageGraphics.drawImage(
	      rocketshipImage,
	      xscrollPosition,
	      yscrollPosition,this);	
	  preImageGraphics.setFont(shipfont);
	  shipstr = "              Heads up! Looks like we got a tail! Start jamming it. Its heading for that small moon.";
	  shipstr += shipstrpad + shipstrpad;
	  if (xscrollPosition > 0)
	   {preImageGraphics.drawString(
	    shipstr.substring(shipstrIndex,shipstrIndex + 11),
	    xscrollPosition + 65,
	    yscrollPosition + rocketshipWidth/2);	
	    if (frameNumber % 2 == 0) shipstrIndex++;
	    if (shipstrIndex + 11 == shipstr.length()) shipstrIndex = 0; 
	    }	
	  if (xscrollPosition >= d.width/3) 
	   {xspeedUp++; 
	    yspeedUp++; 
	    }
	  if (xscrollPosition >= d.width)                      // Setup for next background. 
	   {frameNumber = -1; 
	    backNumber = 3;
	    shipstrIndex = 0;
	    xspeedUp = 0;
	    yspeedUp = 0;
	    }
	  }                                             
	else if (backNumber == 3)                               // Paint on background 3.
	 {xscrollPosition = 
	        (frameNumber % xscrollDistance) - rocketshipWidth + xspeedUp*50;
	  yscrollPosition = d.height/2 + yspeedUp*30;
	  preImageGraphics.drawImage(
	      rocketshipImage,
	      xscrollPosition,
	      yscrollPosition,this);	
	  preImageGraphics.setFont(shipfont);
	  shipstr = "              That's not a moon! That's a space station ... looks like we'll have to fight our way out of this one";
	  shipstr += shipstrpad + shipstrpad;
	  if (xscrollPosition > 0)
	   {preImageGraphics.drawString(
	    shipstr.substring(shipstrIndex,shipstrIndex + 11),
	    xscrollPosition + 60,
	    yscrollPosition + rocketshipWidth/2);	
	    if (frameNumber % 2 == 0) shipstrIndex++;
	    if (shipstrIndex + 11 == shipstr.length()) shipstrIndex = 0; 
	    }	
	  if (xscrollPosition >= d.width/3) 
	   {xspeedUp++; 
	    yspeedUp++; 
	    }
	  if (xscrollPosition >= d.width)                      // Setup for next background. 
	   {frameNumber = -1; 
	    backNumber = 0;
	    shipstrIndex = 0;
	    xspeedUp = 0;
	    yspeedUp = 0;
	    }
	  }                                             
							 // Offscreen preImage completed.
	g.drawImage(preImage,0,0,this);	                // Paint preImage on the screen.
      }
     }
    /** STOP THE ANIMATION THREAD **/

   public void stop()
      {animatorThread = null;     // The user either clicked to stop or left the page,
       preImageGraphics = null;   // so wipe out the current thread and preImage context.
       preImage = null;
       }
     }