Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main {
    public static void main(String[] args) {
        JFrame frame = new JFrame();
        JPanel panel = new JPanel();
        frame.setSize(300, 200);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JButton redButton = new JButton("Red");
        JButton greenButton = new JButton("Green");
        JButton blueButton = new JButton("Blue");
        class Listener extends JPanel implements ActionListener {
            public void actionPerformed(ActionEvent event) {
                Color color;
                if (event.getSource() == redButton) {
                    color = Color.red;
                    redButton.setBackground(color);
                    panel.setBackground(color);
                } else if (event.getSource() == greenButton) {
                    color = Color.green;
                    greenButton.setBackground(color);
                    panel.setBackground(color);
                } else {
                    color = Color.blue;
                    blueButton.setBackground(color);
                    panel.setBackground(color);
                }
                setBackground(color);
                repaint();
            }
        }
        redButton.addActionListener(new Listener());
        greenButton.addActionListener(new Listener());
        blueButton.addActionListener(new Listener());
        panel.add(redButton);
        panel.add(greenButton);
        panel.add(blueButton);
        frame.add(panel);
        frame.setVisible(true);
    }
}