CurrencyConversion.java

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class GUI extends JFrame implements ActionListener{

    JPanel left, topRight, bottomLeft;
    JLabel dollar, can;
    JTextField dolNum,canNum;
    JButton convert, clear;//another way

    public GUI()  {
        left = new JPanel();
        topRight = new JPanel();
        bottomLeft = new JPanel();
        dollar = new JLabel("US Dollars");
        can = new JLabel("Canadian Dollars");
        dolNum = new JTextField();
        canNum = new JTextField();
        convert = new JButton("Convert");
        clear = new JButton("Clear");

        left.setLayout(new GridLayout(3,1));
        left.add(dollar);
        left.add(can);

        topRight.setLayout(left.getLayout());
        topRight.add(dolNum);
        topRight.add(canNum);
        topRight.add(bottomLeft);

        bottomLeft.setLayout(new BorderLayout());
        convert.addActionListener(this);
        bottomLeft.add(convert, BorderLayout.EAST);


        add(left, BorderLayout.WEST);
        add(topRight);

        setTitle("الحمدلله");
        setVisible(true);
        setSize(480,280);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);


    }

    public void actionPerformed (ActionEvent ae)
    {
        if (ae.getSource() == convert)
            canNum.setText(String.valueOf(Double.parseDouble(dolNum.getText()) * 1.5));//value of,, because it only accept String
        else if (ae.getSource() == clear)
        {
            canNum.setText("");
            dolNum.setText("");
        }
    }
}