/** 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 AllanApplet14 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, waitstr3 = ""; Font kirkfont=new Font("TimesRoman",Font.PLAIN,10); FontMetrics kirkfontm = getFontMetrics(kirkfont); String shipstr = ""; String kirkstr = ""; String kirkstrpad = " "; Font titlefont=new Font("TimesRoman",Font.BOLD,24); FontMetrics titlefontm = getFontMetrics(titlefont); String titlestr = ""; Color starblue = new Color(0,100,255); Thread frameThread; Font font=new Font("TimesRoman",Font.BOLD,30); String framestr = ""; 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 background1; Image background2; Image background3; Image background4; Image background5; Image PleiadesClusterImage; Image starbackground; Image kirk; Image picard; Image sisko; Image rocketshipImage; Image torpedo; Image enterprisea1; Image enterprisea2; Image enterprisee1; Image enterprisee2; Image defiant; Image defiant2; Image explosion; Image nothing; Image fire1; Image fire2; Image fire3; Image fire4; Image fire5; Image fire6; MediaTracker tracker; int backNumber = 0; int kirkstrIndex = 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[6]; tracker = new MediaTracker(this); // Spawn the tracker background thread(s) background1 = getImage(getCodeBase(),"images/background1.JPG"); tracker.addImage(background1,0); background2 = getImage(getCodeBase(),"images/background1.JPG"); tracker.addImage(background2,0); background3 = getImage(getCodeBase(),"images/starbackground.gif"); tracker.addImage(background3,0); background4 = getImage(getCodeBase(),"images/starbackground.gif"); tracker.addImage(background4,0); background5 = getImage(getCodeBase(),"images/starbackground.gif"); tracker.addImage(background5,0); backgroundstarImage[0] = background1; tracker.addImage(backgroundstarImage[0],0); backgroundstarImage[1] = background2; tracker.addImage(backgroundstarImage[1],0); backgroundstarImage[2] = background3; tracker.addImage(backgroundstarImage[2],0); backgroundstarImage[3] = background4; tracker.addImage(backgroundstarImage[3],0); backgroundstarImage[4] = background4; tracker.addImage(backgroundstarImage[4],0); backgroundstarImage[5] = background5; tracker.addImage(backgroundstarImage[5],0); nothing = getImage(getCodeBase(),"images/nothing.gif"); tracker.addImage(nothing,0); torpedo = getImage(getCodeBase(),"images/torpedo.GIF"); tracker.addImage(torpedo,0); defiant2 = getImage(getCodeBase(),"images/defiant2.GIF"); tracker.addImage(defiant2,0); fire1 = getImage(getCodeBase(),"images/fire1.gif"); tracker.addImage(fire1,0); fire2 = getImage(getCodeBase(),"images/fire2.gif"); tracker.addImage(fire2,0); fire3 = getImage(getCodeBase(),"images/fire3.gif"); tracker.addImage(fire3,0); fire4 = getImage(getCodeBase(),"images/fire4.gif"); tracker.addImage(fire4,0); fire5 = getImage(getCodeBase(),"images/fire5.gif"); tracker.addImage(fire5,0); fire6 = getImage(getCodeBase(),"images/fire6.gif"); tracker.addImage(fire6,0); picard = getImage(getCodeBase(),"images/picard.jpg"); tracker.addImage(picard,0); sisko = getImage(getCodeBase(),"images/sisko.gif"); tracker.addImage(sisko,0); kirk = getImage(getCodeBase(),"images/kirk.jpg"); tracker.addImage(kirk,0); explosion = getImage(getCodeBase(),"images/explosion.GIF"); tracker.addImage(explosion,0); enterprisea1 = getImage(getCodeBase(),"images/enterprisea1.gif"); tracker.addImage(enterprisea1,0); enterprisea2 = getImage(getCodeBase(),"images/enterprisea2.gif"); tracker.addImage(enterprisea2,0); enterprisee2 = getImage(getCodeBase(),"images/enterprisee2.gif"); tracker.addImage(enterprisee2,0); enterprisee1 = getImage(getCodeBase(),"images/enterprisee1.gif"); tracker.addImage(enterprisee1,0); } /** 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 = "Star Trek: Battle of the Captains' Egos"; waitstr2 = "Loading images, please wait... Depending upon your computer "; waitstr3 = "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()); g.drawString(waitstr3, (d.width - waitfontm.stringWidth(waitstr3))/2, (d.height/2) + (waitfontm.getHeight() + 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. // something strange, exit int kirkWidth = kirk.getWidth(this); // the while loop. int defiant2Width = defiant2.getWidth(this); // Get rocketship image int defiant2Height = defiant2.getHeight(this); // dimensions. int enterprisea1Width = enterprisea1.getWidth(this); // Get rocketship image int enterprisea1Height = enterprisea1.getHeight(this); // dimensions. int enterprisea2Width = enterprisea2.getWidth(this); // Get rocketship image int enterprisea2Height = enterprisea2.getHeight(this); // dimensions. int enterprisee2Width = enterprisee2.getWidth(this); // Get rocketship image int enterprisee2Height = enterprisee2.getHeight(this); int enterprisee1Width = enterprisee1.getWidth(this); // Get rocketship image int enterprisee1Height = enterprisee1.getHeight(this); int xscrollDistance = d.width + enterprisea2Width; int yscrollDistance = d.height + enterprisea2Height; int xscrollPosition = 0; int yscrollPosition = 0; int cycle = 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( "Biggest Ego ? ", d.width - titlefontm.stringWidth("Biggest Ego ? "), titlefontm.getAscent()); //backNumber = 3; if (backNumber == 0) // Paint on background 0. {yscrollPosition = (frameNumber % yscrollDistance) - enterprisea2Height/2 + yspeedUp*10; //while ((yscrollPosition >= (d.height/6) +10)&&(yscrollPosition < (d.height/3) +10)) if (yscrollPosition >= (d.height/6) +10) yspeedUp++; if (yscrollPosition >= (d.height/3) +10) xspeedUp++; // Go to warp speed. xscrollPosition = (frameNumber % xscrollDistance) - enterprisea2Width/2 + xspeedUp*30; preImageGraphics.drawImage(kirk,0,(d.height - 150),this); preImageGraphics.drawImage( enterprisee2, (d.width - enterprisee2Width), (d.height - enterprisee2Height),this); preImageGraphics.drawImage( enterprisea2, xscrollPosition, yscrollPosition,this); preImageGraphics.setColor(Color.red); if ((yscrollPosition >= (d.height/3) +10)&&(xscrollPosition <= d.width - 200)) {preImageGraphics.drawLine(xscrollPosition + 120, yscrollPosition + 50, (d.width - enterprisee2Width + 20), (d.height - enterprisee2Height + 33)); // if (yscrollPosition >= (d.height/3) +10) preImageGraphics.drawImage(explosion, (d.width - enterprisee2Width + 5), (d.height - enterprisee2Height + 25),this); } if ((yscrollPosition >= (d.height/3) +10)&&(xscrollPosition > d.width - 200)) cycle++; // preImageGraphics.setFont(font); // background color (magenta), preImageGraphics.setColor(starblue); preImageGraphics.setFont(kirkfont); kirkstr = " Picard, Your nothing but a 24th century Mr. Clean !!"; kirkstr += kirkstrpad + kirkstrpad + kirkstrpad + kirkstrpad; // Pad shipstr with blanks. if (yscrollPosition > 0) {preImageGraphics.drawString( kirkstr.substring(kirkstrIndex,kirkstrIndex + 21), // Compute current substring 0, d.height - 10); if (frameNumber % 2 == 0) kirkstrIndex++; // Slow down shipstr display. if (kirkstrIndex + 15 == kirkstr.length()) kirkstrIndex = 0; // Start over at } // end of shipstr. if (xscrollPosition >= d.width) {frameNumber = -1; backNumber = 1; kirkstrIndex = 0; yspeedUp = 0; xspeedUp = 0; } } else if (backNumber == 1) // Paint on background 1. {yscrollPosition = (d.height/2) - (frameNumber % yscrollDistance); if (yscrollPosition <= .1*d.height) xspeedUp++; xscrollPosition = (frameNumber % xscrollDistance) - enterprisea2Width + xspeedUp*50; preImageGraphics.drawImage(picard,0,d.height - 150,this); preImageGraphics.drawImage( enterprisee1, xscrollPosition, (yscrollPosition + 15),this); preImageGraphics.drawImage(enterprisea1, (d.width - enterprisea1Width), (d.height - enterprisea1Height),this); preImageGraphics.setColor(Color.red); if ((xscrollPosition >= 65) && (xscrollPosition <= 300)) preImageGraphics.drawLine(xscrollPosition + 150, yscrollPosition + 50, (d.width - enterprisea1Width + 20), (d.height - enterprisea1Height + 33)); if ((xscrollPosition >= 65) && (xscrollPosition <= 300)) preImageGraphics.drawImage(explosion, (d.width - enterprisea1Width + 5), (d.height - enterprisea1Height + 18),this); preImageGraphics.setFont(font); // background color (magenta), preImageGraphics.setColor(starblue); preImageGraphics.setFont(kirkfont); kirkstr = " Kirk, you're an old fogy who wears a rug! Time for you to retire !!"; kirkstr += kirkstrpad + kirkstrpad + kirkstrpad + kirkstrpad; //ADDED EXTRA PADDING HERE // Pad shipstr with blanks. if (yscrollPosition > 0) {preImageGraphics.drawString( kirkstr.substring(kirkstrIndex,kirkstrIndex + 21), // Compute current substring 0,d.height - 10); if (frameNumber % 2 == 0) kirkstrIndex++; // Slow down shipstr display. if (kirkstrIndex + 15 == kirkstr.length()) kirkstrIndex = 0; // Start over at } // end of shipstr. if (xscrollPosition >= d.width) // Setup for next background. {frameNumber = -1; backNumber = 2; kirkstrIndex = 0; xspeedUp = 0; } } else if (backNumber == 2) // Paint on background 2. {yscrollPosition = (frameNumber % yscrollDistance) - defiant2Height/2; if (yscrollPosition >= (d.height/3)) xspeedUp++; // Go to warp speed. xscrollPosition = (frameNumber % xscrollDistance) - defiant2Width/2 + xspeedUp*30; preImageGraphics.drawImage(sisko,0,(d.height - 150), this); preImageGraphics.drawImage(defiant2, xscrollPosition, yscrollPosition,this); if (yscrollPosition >= (d.height/3)) {preImageGraphics.drawImage(torpedo, 170, xscrollPosition, this); preImageGraphics.drawImage(torpedo, 239, (xscrollPosition + 90), this); } //ADDED THIS BRACE preImageGraphics.setFont(font); // background color (magenta), preImageGraphics.setColor(starblue); preImageGraphics.setFont(kirkfont); kirkstr = " Gentlemen, Starfleet grows weary of this bickering, and sent Sisko to settle it...."; kirkstr += kirkstrpad + kirkstrpad + kirkstrpad + kirkstrpad; // Pad shipstr with blanks. if (yscrollPosition > 0) {preImageGraphics.drawString( kirkstr.substring(kirkstrIndex,kirkstrIndex + 21), // Compute current substring 0,d.height - 10); if (frameNumber % 2 == 0) kirkstrIndex++; // Slow down shipstr display. if (kirkstrIndex + 15 == kirkstr.length()) kirkstrIndex = 0; // Start over at } //ADDED THIS BRACE if (xscrollPosition >= d.width) // Setup for next background. {frameNumber = -1; backNumber = 3; kirkstrIndex = 0; xspeedUp = 0; yspeedUp = 0; } } else if (backNumber == 3) // Paint on background 2. {yscrollPosition = (frameNumber % yscrollDistance) - defiant2Height; if (yscrollPosition <= (1)) xspeedUp++; // Go to warp speed. xscrollPosition = (frameNumber % xscrollDistance) - defiant2Width + xspeedUp*30; preImageGraphics.drawImage(enterprisea2, 10, 200, this); preImageGraphics.drawImage(enterprisee1, 225, 210, this); preImageGraphics.drawImage(nothing, xscrollPosition, 1, this); if (xscrollPosition <= (220)) { preImageGraphics.drawImage(torpedo, 170, xscrollPosition, this); preImageGraphics.drawImage(torpedo, 300, (xscrollPosition + 90), this); } //ADDED THIS BRACE & ITS PAIR ABOVE if (xscrollPosition >= d.width) // Setup for next background. {frameNumber = -1; backNumber = 4; kirkstrIndex = 0; xspeedUp = 0; yspeedUp = 0; } } else if (backNumber == 4) // Paint on background 2. {yscrollPosition = (frameNumber % yscrollDistance) - defiant2Height; if (yscrollPosition <= (1)) xspeedUp++; // Go to warp speed. xscrollPosition = (frameNumber % xscrollDistance) - defiant2Width + xspeedUp*30; preImageGraphics.drawImage(fire1, 10,200, this); preImageGraphics.drawImage(fire1, 225, 210, this); preImageGraphics.drawImage(enterprisea2, 10, 200, this); preImageGraphics.drawImage(enterprisee1, 225, 210, this); preImageGraphics.drawImage(nothing, xscrollPosition, 1, this); if (xscrollPosition <= 20) //if ((xscrollPosition >= 1) && (xscrollPosition <= 20)) preImageGraphics.drawImage(fire1, 10,200, this); if ((xscrollPosition >= 21) && (xscrollPosition <= 40)) preImageGraphics.drawImage(fire2, 10,200, this); if ((xscrollPosition >= 41) && (xscrollPosition <= 60)) preImageGraphics.drawImage(fire3, 10,200, this); if ((xscrollPosition >= 61) && (xscrollPosition <= 80)) preImageGraphics.drawImage(fire4, 10,200, this); if ((xscrollPosition >= 81) && (xscrollPosition <= 100)) preImageGraphics.drawImage(fire5, 10,200, this); if ((xscrollPosition >= 101) && (xscrollPosition <= 120)) preImageGraphics.drawImage(fire6, 10,200, this); if ((xscrollPosition >= 121) && (xscrollPosition <=140)) preImageGraphics.drawImage(fire1, 10,200, this); if ((xscrollPosition >= 141) && (xscrollPosition <= 160)) preImageGraphics.drawImage(fire2, 10,200, this); if ((xscrollPosition >= 161) && (xscrollPosition <= 180)) preImageGraphics.drawImage(fire3, 10,200, this); if ((xscrollPosition >= 181) && (xscrollPosition <= 200)) preImageGraphics.drawImage(fire4, 10,200, this); if ((xscrollPosition >= 201) && (xscrollPosition <= 220)) preImageGraphics.drawImage(fire5, 10,200, this); if ((xscrollPosition >= 221) && (xscrollPosition <= 240)) preImageGraphics.drawImage(fire6, 10,200, this); if ((xscrollPosition >= 241) && (xscrollPosition <= 260)) preImageGraphics.drawImage(fire1, 10,200, this); if ((xscrollPosition >= 261) && (xscrollPosition <= 280)) preImageGraphics.drawImage(fire2, 10,200, this); if ((xscrollPosition >= 301) && (xscrollPosition <= 320)) preImageGraphics.drawImage(fire3, 10,200, this); if ((xscrollPosition >= 321) && (xscrollPosition <= 341)) preImageGraphics.drawImage(fire4, 10,200, this); if ((xscrollPosition >= 361) && (xscrollPosition <= 380)) preImageGraphics.drawImage(fire5, 10,200, this); if ((xscrollPosition >= 381) && (xscrollPosition <= 400)) preImageGraphics.drawImage(fire6, 10,200, this); if ((xscrollPosition >= 401) && (xscrollPosition <=420)) preImageGraphics.drawImage(fire1, 10,200, this); if ((xscrollPosition >= 421) && (xscrollPosition <= 440)) preImageGraphics.drawImage(fire2, 10,200, this); if ((xscrollPosition >= 441) && (xscrollPosition <= 460)) preImageGraphics.drawImage(fire3, 10,200, this); if ((xscrollPosition >= 461) && (xscrollPosition <= 480)) preImageGraphics.drawImage(fire4, 10,200, this); if ((xscrollPosition >= 481) && (xscrollPosition <= 500)) preImageGraphics.drawImage(fire5, 10,200, this); if (xscrollPosition <= 20) //if ((xscrollPosition >= 1) && (xscrollPosition <= 20)) preImageGraphics.drawImage(fire1, 225, 210, this); if ((xscrollPosition >= 21) && (xscrollPosition <= 40)) preImageGraphics.drawImage(fire2, 225, 210, this); if ((xscrollPosition >= 41) && (xscrollPosition <= 60)) preImageGraphics.drawImage(fire3, 225, 210, this); if ((xscrollPosition >= 61) && (xscrollPosition <= 80)) preImageGraphics.drawImage(fire4, 225, 210, this); if ((xscrollPosition >= 81) && (xscrollPosition <= 100)) preImageGraphics.drawImage(fire5, 225, 210, this); if ((xscrollPosition >= 101) && (xscrollPosition <= 120)) preImageGraphics.drawImage(fire6, 225, 210, this); if ((xscrollPosition >= 121) && (xscrollPosition <=140)) preImageGraphics.drawImage(fire1, 225, 210, this); if ((xscrollPosition >= 141) && (xscrollPosition <= 160)) preImageGraphics.drawImage(fire2, 225, 210, this); if ((xscrollPosition >= 161) && (xscrollPosition <= 180)) preImageGraphics.drawImage(fire3, 225, 210, this); if ((xscrollPosition >= 181) && (xscrollPosition <= 200)) preImageGraphics.drawImage(fire4, 225, 210, this); if ((xscrollPosition >= 201) && (xscrollPosition <= 220)) preImageGraphics.drawImage(fire5, 225, 210, this); if ((xscrollPosition >= 221) && (xscrollPosition <= 240)) preImageGraphics.drawImage(fire6, 225, 210, this); if ((xscrollPosition >= 241) && (xscrollPosition <= 260)) preImageGraphics.drawImage(fire1, 225, 210, this); if ((xscrollPosition >= 261) && (xscrollPosition <= 280)) preImageGraphics.drawImage(fire2, 225, 210, this); if ((xscrollPosition >= 301) && (xscrollPosition <= 320)) preImageGraphics.drawImage(fire3, 225, 210, this); if ((xscrollPosition >= 321) && (xscrollPosition <= 341)) preImageGraphics.drawImage(fire4, 225, 210, this); if ((xscrollPosition >= 361) && (xscrollPosition <= 380)) preImageGraphics.drawImage(fire5, 225, 210, this); if ((xscrollPosition >= 381) && (xscrollPosition <= 400)) preImageGraphics.drawImage(fire6, 225, 210, this); if ((xscrollPosition >= 401) && (xscrollPosition <=420)) preImageGraphics.drawImage(fire1, 225, 210, this); if ((xscrollPosition >= 421) && (xscrollPosition <= 440)) preImageGraphics.drawImage(fire2, 225, 210, this); if ((xscrollPosition >= 441) && (xscrollPosition <= 460)) preImageGraphics.drawImage(fire3, 225, 210, this); if ((xscrollPosition >= 461) && (xscrollPosition <= 480)) preImageGraphics.drawImage(fire4, 225, 210, this); if ((xscrollPosition >= 481) && (xscrollPosition <= 500)) preImageGraphics.drawImage(fire5, 225, 210, this); //REMOVED THIS BRACE } if (xscrollPosition >= d.width) // Setup for next background. {frameNumber = -1; backNumber = 5; kirkstrIndex = 0; xspeedUp = 0; yspeedUp = 0; } } // Offscreen preImage completed. else if (backNumber == 5) // Paint on background 2. {yscrollPosition = (frameNumber % yscrollDistance) - defiant2Height; if (yscrollPosition <= (1)) xspeedUp++; // Go to warp speed. xscrollPosition = (frameNumber % xscrollDistance) - defiant2Width + xspeedUp*30; // preImageGraphics.drawImage(enterprisea2, 10, 200, this); // preImageGraphics.drawImage(enterprisee1, 225, 210, this); preImageGraphics.drawImage(nothing, xscrollPosition, 1, this); if (xscrollPosition >= d.width) // Setup for next background. {frameNumber = -1; backNumber = 0; kirkstrIndex = 0; xspeedUp = 0; yspeedUp = 0; } } 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; } }