import java.awt.*;
import java.applet.*;

public class BeanJar extends Applet
{
  // Value of PI
  private static final double PI = 3.1416;
  
  // Volume of one bean
  private static final double VOLUME_OF_ONE_BEAN 
    = (PI * 0.125 * 0.125 * 0.15) + (0.25 * 0.25 * 0.15);

  // Our Ad
  Label advertisement = new Label ("How many coffee beans can fit in a jar");

  // Prompt for the user
  Label prompt = new Label ("Enter the jar length and width (whole inches)");
  
  // Field of entering the height
  TextField heightField = new TextField (10);

  // Field of entering the width
  TextField widthField = new TextField (10);

  // Calculate button
  Button calculateButton = new Button ("Calulate");

  // Area for results
  TextArea resultSection = new TextArea (2, 25);

  // Initialize my applet
  public void init ()
    {
      // Add all the GUI items
      add (advertisement);
      add (prompt);
      add (heightField);
      add (widthField);
      add (calculateButton);
      add (resultSection);
    }

  public boolean action (Event event, Object what)
    {
      try
        {
          // Get the height
          String heightString = heightField.getText ();
          int height = Integer.parseInt (heightString);

          // Get the width
          String widthString = widthField.getText ();
          int width = Integer.parseInt (widthString);

          // Calculate the volume of the jar
          double jarVolume = PI * width * height;

          // Calculate the number of beans
          long numberOfBeans = 
            Math.round (jarVolume / VOLUME_OF_ONE_BEAN * 0.6);

          // Make a result string
          String result = "The jar will hold \n" + 
            numberOfBeans + " coffee beans";

          // Set the results
          resultSection.setText (result);
        }      
      catch (Exception exception)
        {          
          //
          // In case of exceptions
          //

          String result = "Cannot understand input";
          
          resultSection.setText (result);
        }

      return true;
    }
}