How do I use a Frame to set up an applet animation?

Question

I am working on this program for a physics class. It is supposed to be an applet which animates a spring. I first set the animation with dummy values and it works fine (aside from a little flicker). I set up a frame which pops up and allows a user to input values. The frame looks and collects the information as I wanted; now I am trying to get these values passed to the init() method of my applet to be the basis of the animation. I was thinking something like JOptionPane; but, I wanted it to be more customized.
This is the inner class in Launcher which prepares information and disposes the frame. I would like to pass this array
"out."
     private class Exe implements ActionListener{
          public void actionPerformed(ActionEvent event){
               String execute = event.getActionCommand();
               if (execute == "Ok"){
                    out = new double[5];
                    for(int c = 0; c < 5; c++){
                         out[c] = Double.parseDouble(input[c].getText());}
                    dispose();}}}}This is the init() method which sets up all the information required for the animation. I want to receive the array here:
public class Spring extends Applet implements Runnable{
     double t = 0;
     double x,v,a,k;
     int s;
     int delay;
     Thread animator;
     double mass, omega, phi,gravity,equilibrium,amplitude, positionI, velocityI, phiHat;
     double scaler;
     Panel buttons;
     Button start;
     Button pause;
     Button back;
     Button forward;
     Button stop;
     Button restart;     
     Frame l;
     public void init(){
          //Opens the menu which allows user inputs
          l = new Launcher();
          l.setSize(500,450);
          l.setVisible(true);
          //Sets the ammount of time the system waits to refresh
          //Smaller numbers create a more accurate picture
          //This is in milliseconds
          delay = 100;
          //Calculates info about the system
          mass = 5;
          equilibrium = .5;
          gravity = 9.8;
          k = (mass * gravity)/equilibrium;
          omega = Math.pow(k/mass,.5);
          //Differential Equation
          positionI = .1;
          velocityI = -.1;
          amplitude = Math.pow(Math.pow((positionI/Math.cos(omega*0)),2)+
                    Math.pow((velocityI/(omega*Math.cos(omega*0))),2),.5);
          phiHat = Math.abs(Math.atan((positionI/Math.cos(omega*0))/(velocityI/(omega*Math.cos(omega*0)))));
          if((positionI/Math.cos(omega*0)) > 0 && (velocityI/(omega*Math.cos(omega*0))) > 0){
               phi = phiHat;}
          if((positionI/Math.cos(omega*0)) < 0 && (velocityI/(omega*Math.cos(omega*0))) < 0){
               phi = Math.PI + phiHat;}
          if((positionI/Math.cos(omega*0)) < 0 && (velocityI/(omega*Math.cos(omega*0))) > 0){
               phi = (2*Math.PI) - phiHat;}
          if((positionI/Math.cos(omega*0)) > 0 && (velocityI/(omega*Math.cos(omega*0))) < 0){
               phi = Math.PI - phiHat;}
          //scales the spring to the animation grid
          if (amplitude !=  0)
               scaler = amplitude / 105;
          else
               scaler = 1;
          //Adds buttons to applet          
          buttons = new Panel();
          buttons.setLayout(new FlowLayout(FlowLayout.CENTER));
          start = new Button("Start");
          buttons.add(start);
          pause = new Button("Pause");
          buttons.add(pause);
          back = new Button("Back");
          buttons.add(back);
          forward = new Button("Forward");
          buttons.add(forward);
          stop = new Button("Stop");
          buttons.add(stop);
          restart = new Button("Restart");
          buttons.add(restart);
          this.setLayout(new BorderLayout());
          add(buttons, BorderLayout.SOUTH);}

Answer 1

I was trying to tweak my animation and I have ran into some problems:
To refresh, I have an applet which animates a spring. The equation which drives the animation is taken from user input which is entered in a frame that launches when the applet loads. The user has the option to control the animation with buttons as opposed to the applet running itself. Anyway, everything worked fine until I rewrote the applet with an image buffer. Now, the frame launches and is automatically placed in the background (on the desktop). The start, stop, and pause buttons work; but the step back and forward buttons do not work. If you have time to offer suggestions they would be appreciated.
Set Up Buttons and Frame:
     public void init(){
          l = new Frame("Information About Your Spring");
          l.setLayout(new GridLayout(4,1));
          directions = new TextArea(text);
          directions.setEditable(false);
          l.add(directions);
          GravityHandler a = new GravityHandler();
          gravityButtons = new Container();
          gravityButtons.setLayout(new GridLayout(bodies.length/4,4));
          gravityL = new JRadioButton[bodies.length];
          g = new ButtonGroup();
          for(int x = 0; x < bodies.length; x++){
               if(bodies[x].equals("Earth")){
                    gravityL[x] = new JRadioButton(bodies[x], true);
                    gravityL[x].addActionListener(a);}
               else{
                    gravityL[x] = new JRadioButton(bodies[x], false);
                    gravityL[x].addActionListener(a);}
               g.add(gravityL[x]);
               gravityButtons.add(gravityL[x]);}
          l.add(gravityButtons);
          lables = new TextField[5];
          input = new TextField[5];
          otherInput = new Container();
          otherInput.setLayout(new GridLayout(3,4,5,5));
          lables[0] = new TextField("Mass:");
          lables[0].setEditable(false);
          otherInput.add(lables[0]);
          input[0] = new TextField(20);
          otherInput.add(input[0]);
          lables[1] = new TextField("Gravity:");
          lables[1].setEditable(false);
          otherInput.add(lables[1]);
          input[1] = new TextField("9.81",20);
          input[1].setEditable(false);
          otherInput.add(input[1]);
          lables[2] = new TextField("Equilibrium:");
          lables[2].setEditable(false);
          otherInput.add(lables[2]);
          input[2] = new TextField(20);
          otherInput.add(input[2]);
          lables[3] = new TextField("Displacement:");
          lables[3].setEditable(false);
          otherInput.add(lables[3]);
          input[3] = new TextField(20);
          otherInput.add(input[3]);
          lables[4] = new TextField("Initial Velocity:");
          lables[4].setEditable(false);
          otherInput.add(lables[4]);
          input[4] = new TextField(20);
          otherInput.add(input[4]);
          l.add(otherInput);
          Exe now = new Exe();
          buttonPlace = new Container();
          buttonPlace.setLayout(new FlowLayout(FlowLayout.CENTER));
          Ok = new Button("Ok");
          Ok.addActionListener(now);
          buttonPlace.add(Ok);
          l.add(buttonPlace);
          l.setSize(425,500);
          l.setResizable(false);
          l.toFront();
          l.setVisible(true);
          delay = 100;
          buttons = new Panel();
          buttons.setLayout(new FlowLayout(FlowLayout.CENTER));
          start = new Button("Start");
          buttons.add(start);
          pause = new Button("Pause");
          buttons.add(pause);
          back = new Button("Back");
          buttons.add(back);
          forward = new Button("Forward");
          buttons.add(forward);
          stop = new Button("Stop");
          buttons.add(stop);
          restart = new Button("Restart");
          buttons.add(restart);
          this.setLayout(new BorderLayout());
          add(buttons, BorderLayout.SOUTH);
          display = createImage(size().width, size().height);
          dspl = display.getGraphics();
          l.toFront();}The frame is handled by ActionListener
Action based on the buttons:
     public boolean action(Event e, Object args){
          if (e.target == start){
               animator = new Thread(this);
               animator.start();}
          if (e.target == stop){
               animator.stop();
               animator = null;
               t = 0;
               repaint();}
          if (e.target == pause){
               animator.stop();
               animator = null;}
          if (e.target == restart){
               animator.stop();
               animator = null;
               t = 0;
               repaint();
               animator = new Thread(this);
               animator.start();}
          if (e.target == back){
               animator.stop();
               animator = null;
               t -= .1;
               repaint();}
          if (e.target == forward){
               animator.stop();
               animator = null;
               t += .1;
               repaint();}
          return true;}
draw animation:
     public void run(){
          while(Thread.currentThread() == animator){
               try{
                    Thread.sleep(delay);}
               catch(InterruptedException e){}
               if(animator != null){
                    t+= .1;}
               else{
                    repaint();}     
               dspl.setColor(Color.black);
               dspl.fillRect(0,0,size().width,size().height);
               dspl.setColor(Color.white);
               k = (mass * gravity)/equilibrium;
               omega = Math.pow(k/mass,.5);
               amplitude = Math.pow(Math.pow((positionI/Math.cos(omega*0)),2)+
                         Math.pow((velocityI/(omega*Math.cos(omega*0))),2),.5);
               phiHat = Math.abs(Math.atan((positionI/Math.cos(omega*0))/(velocityI/(omega*Math.cos(omega*0)))));
               if((positionI/Math.cos(omega*0)) > 0 && (velocityI/(omega*Math.cos(omega*0))) > 0){
                    phi = phiHat;}
               if((positionI/Math.cos(omega*0)) < 0 && (velocityI/(omega*Math.cos(omega*0))) < 0){
                    phi = Math.PI + phiHat;}
               if((positionI/Math.cos(omega*0)) < 0 && (velocityI/(omega*Math.cos(omega*0))) > 0){
                    phi = (2*Math.PI) - phiHat;}
               if((positionI/Math.cos(omega*0)) > 0 && (velocityI/(omega*Math.cos(omega*0))) < 0){
                    phi = Math.PI - phiHat;}
               if (amplitude !=  0)
                    scaler = amplitude / 105;
               else
                    scaler = 1;
               dspl.drawRect(5, 5, 442, 240);
               dspl.drawLine(200,5,200,245);
               dspl.drawLine(200,120,447,120);
               dspl.drawLine(20,20, 20, 230);
               dspl.drawLine(20, 20, 24, 20);
               dspl.drawString( String.format("%.2f m", amplitude) , 24,21);
               dspl.drawLine(20, 230, 24, 230);
               dspl.drawString( String.format("%.2f m", amplitude) , 24,231);
               dspl.drawLine(20, 125, 24, 125);
               dspl.drawString( "0 m", 24, 126);
               x = amplitude*Math.sin((omega*t)+phi); //Calculate position
               v = (amplitude*omega)*Math.cos((omega*t)+phi); //Calculate velovity
               a = -(Math.pow(omega,2)*amplitude)*Math.sin((omega*t)+phi); //Calculate acceleration
               dspl.drawString("Kinematics:", 210,20);
               dspl.drawString(String.format("Time: %.1f Seconds",t), 210, 40);
               dspl.drawString(String.format("Position: %.2f m",x), 210,60 );
               dspl.drawString(String.format("Velocity: %.2f m/s",v), 210,80 );
               dspl.drawString(String.format("Acceleration: %.2f m/sec sq",a),210,100 );
               dspl.drawString("Atributes:", 210, 140);
               dspl.drawString(String.format("Equation: x(t) = %.2fsin(%.2ft + %.3f)",amplitude,omega,phi),210,160);
               dspl.drawString(String.format("Spring Constant: %.2f n/m",k),210,180);
               dspl.drawString(String.format("Period: %.2f Seconds", (2*Math.PI)/omega), 210,200);
               dspl.drawString(String.format("Frequency: %.2f Hz",omega/(2*Math.PI)),210,220);
               dspl.drawString(String.format("Amplitude: %.2f",amplitude),210,240);
               s = (int) (x/scaler + 126);
               dspl.drawLine(128,5,128,s-12);
               dspl.drawString(String.format("%.0f kg Mass",mass), 104, s);
               repaint();}}
     public void update(Graphics g){
          paint(g);}
     public void paint(Graphics g){
          g.drawImage(display,0,0,this);}Thanks