Java апплет — измерение коэффициента вязкости жидкости

public class ball extends Applet
 implements ActionListener, Runnable
{

 public ball()
 {
     timeOn = false;
     timerOn = false;
     timerValue = 0.0D;
     timeStep = 1.0D;
     firstStart = true;
     AppletOn = false;
     menuY = 0;
     time = 0.0D;
     mtimer = null;
     a = 1.0D;
     k = 1.0D;
     r = 2.5D;
 }

 void LoadGraphics()
 {
     MediaTracker mediatracker = new MediaTracker(this);
     showStatus("Loading images...");
     System.out.println("Loading images...");
     backgrnd = getImage(getDocumentBase(), "img/back.jpg");
     mediatracker.addImage(backgrnd, 1);
     lead1 = getImage(getDocumentBase(), "img/lead1.gif");
     mediatracker.addImage(lead1, 2);
     lead2 = getImage(getDocumentBase(), "img/lead2.gif");
     mediatracker.addImage(lead2, 3);
     lead3 = getImage(getDocumentBase(), "img/lead3.gif");
     mediatracker.addImage(lead3, 4);
     steel1 = getImage(getDocumentBase(), "img/steel1.gif");
     mediatracker.addImage(steel1, 5);
     steel2 = getImage(getDocumentBase(), "img/steel2.gif");
     mediatracker.addImage(steel2, 6);
     steel3 = getImage(getDocumentBase(), "img/steel3.gif");
     mediatracker.addImage(steel3, 7);
     try
     {
         mediatracker.waitForAll();
         System.out.println("loaded");
     }
     catch(InterruptedException _ex) { }
     showStatus("Ready");
 }

 public void actionPerformed(ActionEvent actionevent)
 {
     if(actionevent.getActionCommand().equals("Start") || actionevent.getActionCommand().equals("Start position"))
     {
         double d;
         if(gr_ball.getCurrent().getLabel().equals("lead"))
         {
             d = 11.4D;
             ball1 = lead1;
             ball2 = lead2;
             ball3 = lead3;
         } else
         {
             d = 7.7999999999999998D;
             ball1 = steel1;
             ball2 = steel2;
             ball3 = steel3;
         }
         double d1;
         double d2;
         if(gr_liquid.getCurrent().getLabel().equals("glycerine"))
         {
             d1 = 1.26D;
             if(temperature.getCurrent().getLabel().equals("T=283K"))
                 d2 = 3950D;
             else
             if(temperature.getCurrent().getLabel().equals("T=293K"))
                 d2 = 1480D;
             else
             if(temperature.getCurrent().getLabel().equals("T=303K"))
                 d2 = 600D;
             else
             if(temperature.getCurrent().getLabel().equals("T=313K"))
                 d2 = 330D;
             else
                 d2 = 180D;
         } else
         {
             d1 = 0.95999999999999996D;
             d2 = 987D;
         }
         r = (double)Math.round(15D + 10D * Math.random()) / 10D;
         piccoef = 50D / r / 18D;
         a = (1.0D - d1 / d) * 9.8100000000000005D;
         k = (450D * d2) / r / r / d;
         if(rEdit != null)
             rEdit.setText(String.valueOf(r));
     }
     if(actionevent.getActionCommand().equals("Start"))
     {
         if(firstStart)
             firstStart = false;
         time = 0.0D;
         start();
     } else
     if(actionevent.getActionCommand().equals("Start position"))
     {
         time = 0.0D;
         timerValue = 0.0D;
         timerValueEdit.setText("0");
         stop();
     } else
     if(actionevent.getActionCommand().equals("Timer"))
     {
         if(timerOn)
         {
             timerOn = false;
         } else
         {
             timerValue = 0.0D;
             timerOn = true;
         }
     } else
     if(actionevent.getActionCommand().equals("Stop"))
     {
         stop();
         timerOn = false;
     }
     recalc();
     repaint();
 }
public void init()
 {
     setLayout(null);
     setSize(570, 450);
     setBackground(new Color(0xc0c0c0));
     menuY += 5;
     StartButton = new Button();
     StartButton.setLabel("Start");
     StartButton.setBounds(5, menuY, 50, 20);
     StartButton.setBackground(new Color(0xc0c0c0));
     StartButton.addActionListener(this);
     add(StartButton);
     StopButton = new Button();
     StopButton.setLabel("Stop");
     StopButton.setBounds(65, menuY, 50, 20);
     StopButton.setBackground(new Color(0xc0c0c0));
     StopButton.addActionListener(this);
     add(StopButton);
     menuY += 30;
     TimerButton = new Button();
     TimerButton.setLabel("Timer");
     TimerButton.setBounds(5, menuY, 50, 20);
     TimerButton.setBackground(new Color(0xc0c0c0));
     TimerButton.addActionListener(this);
     add(TimerButton);
     timerValueEdit = new TextField();
     timerValueEdit.setEditable(false);
     timerValueEdit.setText("0");
     timerValueEdit.setBounds(65, menuY, 50, 20);
     add(timerValueEdit);
     menuY += 30;
     ResetButton = new Button();
     ResetButton.setLabel("Start position");
     ResetButton.setBounds(5, menuY, 110, 20);
     ResetButton.setBackground(new Color(0xc0c0c0));
     ResetButton.addActionListener(this);
     add(ResetButton);
     menuY += 30;
     timeStep = 12D;
     gr_ball = new CheckboxGroup();
     gr_liquid = new CheckboxGroup();
     temperature = new CheckboxGroup();
     lead = new Checkbox("lead", gr_ball, true);
     steel = new Checkbox("steel", gr_ball, false);
     glycerine = new Checkbox("glycerine", gr_liquid, true);
     kerosene = new Checkbox("castor oil", gr_liquid, false);
     t1 = new Checkbox("T=283K", temperature, true);
     t2 = new Checkbox("T=293K", temperature, false);
     t3 = new Checkbox("T=303K", temperature, false);
     t4 = new Checkbox("T=313K", temperature, false);
     t5 = new Checkbox("T=323K", temperature, false);
     lead.setBounds(5, menuY, 100, 15);
     menuY += 30;
     steel.setBounds(5, menuY, 100, 15);
     menuY += 30;
     glycerine.setBounds(5, menuY, 100, 15);
     menuY += 30;
     kerosene.setBounds(5, menuY, 100, 15);
     menuY += 30;
     t1.setBounds(5, menuY, 100, 15);
     menuY += 30;
     t2.setBounds(5, menuY, 100, 15);
     menuY += 30;
     t3.setBounds(5, menuY, 100, 15);
     menuY += 30;
     t4.setBounds(5, menuY, 100, 15);
     menuY += 30;
     t5.setBounds(5, menuY, 100, 15);
     menuY += 30;
     add(lead);
     add(steel);
     add(glycerine);
     add(kerosene);
     add(t1);
     add(t2);
     add(t3);
     add(t4);
     add(t5);
     rLabel = new Label("r (10^-4 m)");
     rLabel.setBounds(5, menuY, 55, 15);
     add(rLabel);
     rEdit = new TextField();
     rEdit.setEditable(false);
     rEdit.setText("2.5");
     rEdit.setBounds(65, menuY, 50, 20);
     add(rEdit);
     menuY += 30;
     heightLabel = new Label("height (cm)");
     heightLabel.setBounds(5, menuY, 50, 15);
     add(heightLabel);
     HeightEdit = new TextField();
     HeightEdit.setText("0");
     HeightEdit.setBounds(65, menuY, 50, 17);
     add(HeightEdit);
     menuY += 30;
     backbuf = createImage(570, 450);
     LoadGraphics();
     ball1 = lead1;
     ball2 = lead2;
     ball3 = lead3;
     r = (double)Math.round(15D + 10D * Math.random()) / 10D;
     piccoef = 50D / r / 18D;
     recalc();
 }

 public void paint(Graphics g)
 {
     g.translate(120, 0);
     g.drawImage(backgrnd, 0, 0, this);
     if((48D - r * 18D) + x * 294D < 22D)
         g.drawImage(ball1, (int)(235D - r * 9D), (int)((48D - r * 18D) + x * 294D),
(int)(235D + r * 9D), 23, 0, 0, ball1.getWidth(this), (int)(((-25D + r * 18D) - x * 294D) * piccoef), this);
     if((48D - r * 18D) + x * 294D <= 22D)
         g.drawImage(ball2, (int)(235D - r * 9D), 23, (int)(235D + r * 9D), 48, 0,
(int)(((-25D + r * 18D) - x * 294D) * piccoef), ball1.getWidth(this), (int)((r * 18D - x * 294D) * piccoef), this);
     else
     if(-r * 18D + x * 294D < -1D)
         g.drawImage(ball2, (int)(235D - r * 9D), (int)((48D - r * 18D) + x * 294D),
(int)(235D + r * 9D), 48, 0, 0, ball1.getWidth(this), (int)((r * 18D - x * 294D) * piccoef), this);
     if(-r * 18D + x * 294D < 0.0D)
         g.drawImage(ball3, (int)(235D - r * 9D), 48, (int)(235D + r * 9D), (int)(48D + x * 294D), 0,
(int)((r * 18D - x * 294D) * piccoef), ball1.getWidth(this), ball1.getHeight(this), this);
     else
         g.drawImage(ball3, (int)(235D - r * 9D), (int)((48D - r * 18D) + x * 294D), (int)(235D + r * 9D),
(int)(48D + x * 294D), 0, 0, ball1.getWidth(this), ball1.getHeight(this), this);
     g.setColor(new Color(0, 0, 0));
 }
void recalc()
 {
     x = ((a / k / k) * Math.exp(-k * time) + (a / k) * time) - a / k / k;
     if(x > 1.1499999999999999D)
         x = 1.1499999999999999D;
     Double double1 = new Double(x);
     if(HeightEdit != null)
         HeightEdit.setText(double1.toString());
 }

 public void run()
 {
     do
         try
         {
             if(timeOn)
                 time += timeStep;
             if(timerOn)
             {
                 timerValue += timeStep;
                 timerValue = (double)Math.round(timerValue * 10D) / 10D;
                 timerValueEdit.setText(String.valueOf(timerValue));
             }
             recalc();
             repaint();
             Thread.sleep(100L);
         }
         catch(InterruptedException _ex)
         {
             stop();
         }
     while(true);
 }

 public void start()
 {
     if(!firstStart)
     {
         timeOn = true;
         if(mtimer == null)
         {
             mtimer = new Thread(this);
             mtimer.start();
         }
     }
 }

 public void stop()
 {
     if(mtimer != null)
     {
         mtimer.stop();
         mtimer = null;
     }
 }

 public void update(Graphics g)
 {
     paint(backbuf.getGraphics());
     g.drawImage(backbuf, 0, 0, this);
 }

 private Button StartButton;
 private Button StopButton;
 private Button ResetButton;
 private Button TimerButton;
 private TextField timerValueEdit;
 private boolean timeOn;
 protected boolean timerOn;
 protected double timerValue;
 protected double timeStep;
 private static final int WIDTH = 450;
 private static final int HEIGHT = 450;
 private static final int TaskBar = 120;
 private boolean firstStart;
 private boolean AppletOn;
 private int oldX;
 private int oldY;
 protected int menuY;
 protected double time;
 Image backbuf;
 Thread mtimer;
 Checkbox lead;
 Checkbox steel;
 Checkbox glycerine;
 Checkbox kerosene;
 Checkbox t1;
 Checkbox t2;
 Checkbox t3;
 Checkbox t4;
 Checkbox t5;
 CheckboxGroup gr_ball;
 CheckboxGroup gr_liquid;
 CheckboxGroup temperature;
 Label rLabel;
 TextField rEdit;
 Label heightLabel;
 TextField HeightEdit;
 double a;
 double k;
 double r;
 final double nk = 987D;
 final double ng1 = 3950D;
 final double ng2 = 1480D;
 final double ng3 = 600D;
 final double ng4 = 330D;
 final double ng5 = 180D;
 final double rg = 1.26D;
 final double rk = 0.95999999999999996D;
 final double rl = 11.4D;
 final double rs = 7.7999999999999998D;
 double piccoef;
 Image backgrnd;
 Image lead1;
 Image lead2;
 Image lead3;
 Image steel1;
 Image steel2;
 Image steel3;
 Image ball1;
 Image ball2;
 Image ball3;
 double x;
}