/** 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,10); 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[]; //[] means a list of things Image AndromedaImage; Image MilkywayHydrogenImage; Image PleiadesClusterImage; //Image borgcubeImage; // Not currently being used. Image rocketshipImage; Image InfraredUranusImage; MediaTracker tracker; //load all the image first then start int backNumber = 0; //background number int shipstrIndex = 0; //where the sting going to cross the screen int xspeedUp = 0; //increase the ship goes to x direction int yspeedUp = 0; //increase the ship speed goes to y direction /** INITIALIZE THE APPLET **/ public void init() {setBackground(Color.black); String str; int fps = 50; // 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]; //3 means three images in tracker = new MediaTracker(this); // Spawn the tracker background thread(s) AndromedaImage = getImage(getCodeBase(),"images/am5hst.jpg"); tracker.addImage(AndromedaImage,0); MilkywayHydrogenImage = getImage(getCodeBase(),"images/nHI_alt_skyview.jpg"); tracker.addImage(MilkywayHydrogenImage,0); PleiadesClusterImage = getImage(getCodeBase(),"images/pleiades2.gif"); tracker.addImage(PleiadesClusterImage,0); InfraredUranusImage = getImage(getCodeBase(),"images/space1.jpg"); tracker.addImage(InfraredUranusImage,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] = InfraredUranusImage; tracker.addImage(backgroundstarImage[3],0); //borgcubeImage = getImage(getCodeBase(),"images/borgcube.jpg"); //tracker.addImage(borgcubeImage,0); rocketshipImage = getImage(getCodeBase(),"images/rocketship.gif"); //another image by itself 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(starblue); preImageGraphics.drawString( "Lost in Space ? ", d.width - titlefontm.stringWidth("Lost in Space ? "), 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 = " Hmmm..., looks like Andromeda... Let's warp in and check it out !"; shipstr += shipstrpad + shipstrpad; // Pad shipstr with blanks. if (yscrollPosition > 0) {preImageGraphics.drawString( shipstr.substring(shipstrIndex,shipstrIndex + 11), // Compute current substring xscrollPosition + 27, // 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 = " Where am I ?? This looks like a Hydrogen-only view of the Milky Way... Bye !"; shipstr += shipstrpad + shipstrpad; if (yscrollPosition < .62*d.height) {preImageGraphics.drawString( shipstr.substring(shipstrIndex,shipstrIndex + 11), xscrollPosition + 27, 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 = " The Pleiades Cluster ?? With HyperDrive you never know... Uh Oh !"; shipstr += shipstrpad + shipstrpad; if (xscrollPosition > 0) {preImageGraphics.drawString( shipstr.substring(shipstrIndex,shipstrIndex + 11), xscrollPosition + 27, 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 = " Look the pretty uranus"; shipstr += shipstrpad + shipstrpad; if (xscrollPosition > 1) {preImageGraphics.drawString( shipstr.substring(shipstrIndex,shipstrIndex + 11), xscrollPosition + 27, 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; } }