CIS 260 IOapalooza6.java

Code

/*
    IOapalooza6.java
    CIS 260
    David Klick
    2006-01-18

    This program is IOapalooza5.java slightly modified
    to be its own GUI.
*/

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

public class IOapalooza6 extends JFrame {
    public IOapalooza6() {
        this("");
    }
    
    public IOapalooza6(String s) {
        super(s);
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
    
    public void createAndShowGUI() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Container c = getContentPane();
        c.setLayout(new GridLayout(2, 2, 2, 5));
        final JTextField txt = new JTextField();
        txt.addFocusListener(new FocusListener() {
            public void focusGained(FocusEvent e) {
                txt.setSelectionStart(0);
                txt.setSelectionEnd(txt.getText().length());
            }
            public void focusLost(FocusEvent e) {}
        });

        final JLabel lbl = new JLabel();
        JButton btnAdd = new JButton("<html><b><i><font color='green'>Add</font></i></b></html>");
        btnAdd.setMnemonic('a');
        btnAdd.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                double sum = 0.0, num = 0.0;
                String strSum = lbl.getText();
                if (strSum.length() > 0) sum = Double.parseDouble(strSum);
                try {
                    String strNum = txt.getText();
                    num = Double.parseDouble(strNum);
                    sum += num;
                    txt.setText("");
                } catch (NumberFormatException e2) {
                    txt.setSelectionStart(0);
                    txt.setSelectionEnd(txt.getText().length());
                }
                lbl.setText("" + sum);
                txt.requestFocusInWindow();
            }
        });
        getRootPane().setDefaultButton(btnAdd);

        JButton btnExit = new JButton("Exit");
        btnExit.setMnemonic('x');
        btnExit.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.exit(0);
            }
        });
        c.add(txt);
        c.add(lbl);
        c.add(btnAdd);
        c.add(btnExit);
        setSize(200, 110);
        setVisible(true);
    }

    public static void main(String[] args) {
        IOapalooza6 app = new IOapalooza6("Adding Application");
    }
}