package chapter2;

import javax.swing.*;

import java.awt.*;

import java.awt.event.ActionListener;

public class ComputeSquare extends JFrame

{

JTextField number;

JTextField square;

JButton submit;

JPanel panel;

public ComputeSquare()

{

number = new JTextField(10);

square = new JTextField(10);

submit = new JButton("Submit");

submit.addActionListener( x -> {

try {

int num = Integer.parseInt(number.getText());

square.setText(Integer.toString(num*num));

}

catch (NumberFormatException e) {

System.out.println(number.getText()

+ " is not a number");

}

});

panel = new JPanel();

setSize(200,130);

panel.add(number);

panel.add(square);

panel.add(submit);

add(panel);

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setVisible(true);

}

public static void main(String[] args)

{

new ComputeSquare();

}

}