1// Aim: Program to perform GUI operations (Traffic Light Simulator).
2import javax.swing.*;
3import java.awt.*;
4import java.awt.event.ActionEvent;
5import java.awt.event.ActionListener;
6
7public class TrafficLightSimulator extends JFrame implements ActionListener {
8    private JRadioButton redButton;
9    private JRadioButton yellowButton;
10    private JRadioButton greenButton;
11    private JPanel lightPanel;
12
13    public TrafficLightSimulator() {
14        setTitle("Traffic Light Simulator");
15        setSize(300, 400);
16        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
17        setLayout(new BorderLayout());
18
19        // Create radio buttons
20        redButton = new JRadioButton("Red");
21        yellowButton = new JRadioButton("Yellow");
22        greenButton = new JRadioButton("Green");
23
24        // Group the radio buttons
25        ButtonGroup group = new ButtonGroup();
26        group.add(redButton);
27        group.add(yellowButton);
28        group.add(greenButton);
29
30        // Add action listeners
31        redButton.addActionListener(this);
32        yellowButton.addActionListener(this);
33        greenButton.addActionListener(this);
34
35        // Create a panel for the buttons
36        JPanel buttonPanel = new JPanel();
37        buttonPanel.setLayout(new GridLayout(3, 1));
38        buttonPanel.add(redButton);
39        buttonPanel.add(yellowButton);
40        buttonPanel.add(greenButton);
41
42        // Create a panel for the lights
43        lightPanel = new JPanel() {
44            @Override
45            protected void paintComponent(Graphics g) {
46                super.paintComponent(g);
47                g.setColor(Color.BLACK);
48                g.fillRect(100, 50, 100, 300);
49
50                if (redButton.isSelected()) {
51                    g.setColor(Color.RED);
52                    g.fillOval(125, 75, 50, 50);
53                } else {
54                    g.setColor(Color.DARK_GRAY);
55                    g.fillOval(125, 75, 50, 50);
56                }
57
58                if (yellowButton.isSelected()) {
59                    g.setColor(Color.YELLOW);
60                    g.fillOval(125, 175, 50, 50);
61                } else {
62                    g.setColor(Color.DARK_GRAY);
63                    g.fillOval(125, 175, 50, 50);
64                }
65
66                if (greenButton.isSelected()) {
67                    g.setColor(Color.GREEN);
68                    g.fillOval(125, 275, 50, 50);
69                } else {
70                    g.setColor(Color.DARK_GRAY);
71                    g.fillOval(125, 275, 50, 50);
72                }
73            }
74        };
75
76        add(buttonPanel, BorderLayout.WEST);
77        add(lightPanel, BorderLayout.CENTER);
78    }
79
80    public void actionPerformed(ActionEvent e) {
81        lightPanel.repaint();
82    }
83
84    public static void main(String[] args) {
85        SwingUtilities.invokeLater(() -> {
86            TrafficLightSimulator frame = new TrafficLightSimulator();
87            frame.setVisible(true);
88        });
89    }
90}