Notes

package hw1;

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;

public class Homework4 extends JFrame implements ActionListener {
private JComboBox<String> cb;
private JRadioButton r1, r2, r3, r4;
private ButtonGroup bg;
private JCheckBox ch1, ch2, ch3, ch4, ch5, ch6;
private JButton b1, b2;
private JLabel lb1, lb2, lb3;
private JTextArea tf;
private String[] String = { "1", "2", "3", "4" };

public Homework4() {
// TODO Auto-generated constructor stub

cb = new JComboBox<>(String);
cb.setBounds(120, 20, 90, 20);
this.add(cb);


lb1 = new JLabel("Grade");
lb1.setBounds(20, 20, 70, 20);
this.add(lb1);
lb2 = new JLabel("Department");
lb2.setBounds(20, 60, 70, 20);
this.add(lb2);
lb3 = new JLabel("Cources");
lb3.setBounds(20, 100, 70, 20);
this.add(lb3);


r1 = new JRadioButton("MM");
r2 = new JRadioButton("CS");
r3 = new JRadioButton("IC");
r4 = new JRadioButton("EE");
r1.setBounds(120, 60, 50, 20);
r2.setBounds(180, 60, 50, 20);
r3.setBounds(240, 60, 50, 20);
r4.setBounds(300, 60, 50, 20);
this.add(r1);
this.add(r2);
this.add(r3);
this.add(r4);

ch1 = new JCheckBox("JAVA");
ch1.setBounds(120, 100, 100, 20);
this.add(ch1);
ch2 = new JCheckBox("Network");
ch2.setBounds(230, 100, 100, 20);
this.add(ch2);
ch3 = new JCheckBox("Web design");
ch3.setBounds(120, 140, 100, 20);
this.add(ch3);
ch4 = new JCheckBox("Security");
ch4.setBounds(230, 140, 100, 20);
this.add(ch4);
ch5 = new JCheckBox("C++");
ch5.setBounds(120, 180, 100, 20);
this.add(ch5);
ch6 = new JCheckBox("Circuit");
ch6.setBounds(230, 180, 100, 20);
this.add(ch6);

// button
b1 = new JButton("Show");
b1.setBounds(145, 220, 70, 20);
this.add(b1);
b2 = new JButton("Clear");
b2.setBounds(230, 220, 70, 20);
this.add(b2);

// buttongroup
bg = new ButtonGroup();
bg.add(r1);
bg.add(r2);
bg.add(r3);
bg.add(r4);

// textfield
tf = new JTextArea();
tf.setBounds(10, 260, 500, 180);
this.add(tf);

// actionListener
r1.addActionListener(this);
r2.addActionListener(this);
r3.addActionListener(this);
r4.addActionListener(this);
b1.addActionListener(this);
b2.addActionListener(this);
ch1.addActionListener(this);
ch2.addActionListener(this);
ch3.addActionListener(this);
ch4.addActionListener(this);
ch5.addActionListener(this);
ch6.addActionListener(this);
cb.addActionListener(this);

this.setTitle("Form");
this.setLayout(null);
this.setSize(550, 500);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

String grade = "You are Freshman";
String dep;

@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
if (e.getSource() == cb) {
if (cb.getSelectedIndex() == 0) {
grade = "You are Freshman";
} else if (cb.getSelectedIndex() == 1) {
grade = "You are Sophomore";
} else if (cb.getSelectedIndex() == 2) {
grade = "You are Junior";
} else if (cb.getSelectedIndex() == 3) {
grade = "You are Senior";
}
}

if (e.getSource() == r1) {
dep = r1.getText();
}
if (e.getSource() == r2) {
dep = r2.getText();
}
if (e.getSource() == r3) {
dep = r3.getText();
}
if (e.getSource() == r4) {
dep = r4.getText();

}
if (e.getSource() == b1) {
tf.setText("");
tf.append(grade + " in " + dep + ".n");
tf.append("You selected following courses: ");

if (ch1.isSelected() == true) {
tf.append(ch1.getText() + ", ");
}

if (ch2.isSelected() == true) {
tf.append(ch2.getText() + ", ");
}
if (ch3.isSelected() == true) {
tf.append(ch3.getText() + ", ");
}
if (ch4.isSelected() == true) {
tf.append(ch4.getText() + ", ");
}
if (ch5.isSelected() == true) {
tf.append(ch5.getText() + ", ");
}
if (ch6.isSelected() == true) {
tf.append(ch6.getText() + ", ");
}
Document doc = tf.getDocument();
try {
doc.remove(doc.getLength() - 2, 1);
} catch (BadLocationException e1) {
e1.printStackTrace();
}
}
if (e.getSource() == b2) {
tf.setText("");
ch1.setSelected(false);
ch2.setSelected(false);
ch3.setSelected(false);
ch4.setSelected(false);
ch5.setSelected(false);
ch6.setSelected(false);
cb.setSelectedIndex(0);
bg.clearSelection();
}
}

}