/*
 * "Grundkurs Programmieren in Java - Band 2 (2. Auflage, 2006)I"
 * 2003-2006, Carl Hanser Verlag
 * Loesungsvorschlag zu Aufgabe (Version 2.0)
 * (c) 2002 D. Ratz, J. Scheffler, D. Seese, J. Wiesenberger
 *
 */

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;

public class SinCosApplet extends JApplet{
  
  private Container      c;
  private JTextField     argument;
  private JButton        executeButton;
  private JCheckBox      sinCheckbox;
  private JCheckBox      cosCheckbox;
  private ButtonGroup funktion = new ButtonGroup();
  private JLabel         argumentLabel, resultLabel;
  
  public void init() {
    c = getContentPane();
    c.setFont(new Font("Courier", Font.BOLD, 28));
    c.setLayout(new GridLayout(2, 3) );
    c.add(argumentLabel = new JLabel("Argument", JLabel.CENTER));
    sinCheckbox = new JCheckBox("SINUS", true);
    funktion.add(sinCheckbox);
    c.add(sinCheckbox);
    executeButton = new JButton("Berechne");
    c.add(executeButton);
    executeButton.addActionListener(new ExecuteListener());
    argument = new JTextField(4);
    c.add(argument);
    cosCheckbox = new JCheckBox("COSINUS", false);
    funktion.add(cosCheckbox);
    c.add(cosCheckbox);
    c.add(resultLabel = new JLabel(""));
    resultLabel.setOpaque(true);
    resultLabel.setBackground(Color.WHITE);
  }
  
  class ExecuteListener implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      try {
        double arg = Double.valueOf(argument.getText()).doubleValue();
        double result;
        if (sinCheckbox.isSelected())
          result = Math.sin(arg);
        else
          result = Math.cos(arg);
        resultLabel.setText("" + result);
      }
      catch (Exception ex) {
        resultLabel.setText("Unzulaessige Eingabe!");
      }
    }
  }
}