/*
  This applet simulates an object falling with
  a constant gravitational acceleration.
*/
/*
<applet code = "FallingObject" height=400 width=340>
</applet>
*/
import java.applet.*;
import java.awt.*;
import java.awt.event.*;

/*--------------------------------------------------*/
public class FallingObject extends Applet implements ActionListener{
  BoxShoot shoot;

  Button    startBt;
  TextField nDropsText;
  TextField gText;
  TextField speedUpText;
  TextField elevationText;

  int nDropsDefault      =     1;
  double gDefault        = 980.0;
  double speedUpDefault  =   1.0;
  double elevationDefault= 200.0;

  int nDrops;
  int dropCount=0;
  double g;
  double speedUp;
  double elevation;

// Add detector setup here
  G_Detector detector=null;

/*--------------------------------------------------*/
//
  public void init(){
    setBackground(Color.blue);
    setLayout(new BorderLayout());

    nDrops = nDropsDefault;
    g = gDefault;
    speedUp = speedUpDefault;
    elevation = elevationDefault;

    shoot = new BoxShoot(nDrops, speedUp, g, elevation,this);
    add("West",shoot);

    Panel controls = new Panel(new BorderLayout());
    controls.setBackground(Color.white);

    startBt = new Button("Start");
    startBt.addActionListener(this);
    Panel bp0 = new Panel();
    bp0.add(startBt);
    controls.add("West",bp0);

    Panel entriesPane = new Panel();
    entriesPane.setLayout(new GridLayout(4,2));

    Panel lp0 = new Panel(new FlowLayout(FlowLayout.RIGHT));
    lp0.add(new Label("N-drops:"));
    entriesPane.add(lp0);

    nDropsText = new TextField(""+nDrops,4);
    nDropsText.addActionListener(this);
    Panel pt0 = new Panel(new FlowLayout(FlowLayout.LEFT));
    pt0.add(nDropsText);
    entriesPane.add(pt0);

    Panel lp1 = new Panel(new FlowLayout(FlowLayout.RIGHT));
    lp1.add(new Label("g(cm/s**2)="));
    entriesPane.add(lp1);

    gText = new TextField(""+g,4);
    gText.addActionListener(this);
    Panel pt1 = new Panel(new FlowLayout(FlowLayout.LEFT));
    pt1.add(gText);
    entriesPane.add(pt1);

    Panel lp2 = new Panel(new FlowLayout(FlowLayout.RIGHT));
    lp2.add(new Label("FrameRate:"));
    entriesPane.add(lp2);

    speedUpText = new TextField(""+speedUp,4);
    speedUpText.addActionListener(this);
    Panel pt2 = new Panel(new FlowLayout(FlowLayout.LEFT));
    pt2.add(speedUpText);
    entriesPane.add(pt2);

    Panel lp3 = new Panel(new FlowLayout(FlowLayout.RIGHT));
    lp3.add(new Label("Height(cm):"));
    entriesPane.add(lp3);

    elevationText = new TextField(""+elevation,4);
    elevationText.addActionListener(this);
    Panel pt3 = new Panel(new FlowLayout(FlowLayout.LEFT));
    pt3.add(elevationText);
    entriesPane.add(pt3);

    controls.add("East",entriesPane);

    add("South",controls);

    // Add the detector
    detector = new G_Detector( shoot.dY, shoot.dX);
    add("East",detector);
    detector.init();

  }
/*--------------------------------------------------*/
  public void dropDone () {
    detector.eventDone();
    dropCount--;
    if(dropCount > 0){
       detector.eventStart();
       shoot.start();
    }
  }
/*--------------------------------------------------*/
  public void actionPerformed ( ActionEvent e) {
    Object src = e.getSource();
    String str;

    if( src == startBt) {
      checkTextFields();
      dropCount = nDrops;
      detector.eventStart();
      shoot.start();

    } else if(src == nDropsText){
      str = nDropsText.getText();
     try{
        nDrops = Integer.valueOf(str).intValue();
      } catch ( NumberFormatException ex){
        nDrops = nDropsDefault;
        nDropsText.setText(""+nDropsDefault);
      }
      shoot.setnDrops(nDrops);

    } else if(src == gText){
      str = gText.getText();
      try{
        g = Double.valueOf(str).doubleValue();
      } catch ( NumberFormatException ex){
        g = gDefault;
        gText.setText(""+gDefault);
      }
      shoot.setGrav(g);

    } else if(src == speedUpText){
      str = speedUpText.getText();
      try{
        speedUp = Double.valueOf(str).doubleValue();
      } catch ( NumberFormatException ex){
        speedUp = speedUpDefault;
        speedUpText.setText(""+speedUpDefault);
      }
      shoot.setSpeedUp(speedUp);

    } else if(src == elevationText){
      str = elevationText.getText();
      try{
        elevation = Double.valueOf(str).doubleValue();
      } catch ( NumberFormatException ex){
        elevation = elevationDefault;
        elevationText.setText(""+elevationDefault);
      }
      shoot.setElevation(elevation);
    }
  }
/*--------------------------------------------------*/
  void checkTextFields(){

  String str = nDropsText.getText();
  try{
        nDrops = Integer.valueOf(str).intValue();
  } catch ( NumberFormatException ex){
    nDrops = nDropsDefault;
    nDropsText.setText(""+nDropsDefault);
  }
  shoot.setnDrops(nDrops);

  str = gText.getText();
  try{
     g = Double.valueOf(str).doubleValue();
  } catch ( NumberFormatException ex){
     g = gDefault;
     gText.setText(""+gDefault);
  }
  shoot.setGrav(g);

  str = speedUpText.getText();
  try{
     speedUp = Double.valueOf(str).doubleValue();
  } catch ( NumberFormatException ex){
     speedUp = speedUpDefault;
     speedUpText.setText(""+speedUpDefault);
  }
  shoot.setSpeedUp(speedUp);

  str = elevationText.getText();
  try{
     elevation = Double.valueOf(str).doubleValue();
  } catch ( NumberFormatException ex){
     elevation = elevationDefault;
     elevationText.setText(""+elevationDefault);
  }
  shoot.setElevation(elevation);

}
/*--------------------------------------------------*/
  public Insets getInsets(){
    return new Insets(2,2,2,2);
  }

}