/*
    JApplet1.java
    CIS 160
    David Klick
    2011-04-20

    Demonstrates a simple JApplet with two text boxes used
    for input, a label for output, and one button used to
    make the applet work.
*/

/*
<applet code="JApplet1" width="200" height="70">
</applet>
*/

import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class JApplet1 extends JApplet {
    JTextField txt1, txt2;
    JLabel lblOut;

    public void init() {
        // get containers set up
        Container c = getContentPane();
        JPanel pnlTop = new JPanel();
        JPanel pnlBottom = new JPanel();

        // set up layout managers
        c.setLayout(new GridLayout(2,1));
        pnlTop.setLayout(new GridLayout(1,3));
        pnlBottom.setLayout(new FlowLayout());

        // create components
        txt1 = new JTextField();
        txt2 = new JTextField();
        lblOut = new JLabel();
        JButton btnAdd = new JButton("Add Numbers");

        // place components in containers
        pnlTop.add(txt1);
        pnlTop.add(txt2);
        pnlTop.add(lblOut);
        pnlBottom.add(btnAdd);

        // nest containers to get full layout
        c.add(pnlTop);
        c.add(pnlBottom);

        // add ActionListener to make add button work
        btnAdd.addActionListener(new AddListener());

    }
    public void start() {}
    public void paint(Graphics g) { super.paint(g); }
    public void stop() {}
    public void destroy() {}
    class AddListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            double num1=0.0, num2=0.0, tot=0.0;
            try {
                num1 = Double.parseDouble(txt1.getText());
                num2 = Double.parseDouble(txt2.getText());
                tot = num1 + num2;
                lblOut.setText("" + tot);
            } catch (NumberFormatException nfe) {
                lblOut.setText("Error");
            }

        }
    }
}