Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.Random;

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

public class Main {
    static int N = 4;

    public static void main(String[] args) {
        JFrame frame = new JFrame();
        frame.setLayout(new GridLayout(N, N));
        for (int i = 0; i < N * N; i++) {
            frame.add(new CirclePanel());
        }
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }
}

class CirclePanel extends JPanel {
    static final Random r = new Random();

    public CirclePanel() {
        this.setPreferredSize(new Dimension(80, 80));
        this.setForeground(new Color(r.nextInt()));
        this.addMouseListener(new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
                update();
            }
        });
    }

    public void update() {
        this.setForeground(new Color(r.nextInt()));
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        Dimension size = this.getSize();
        int d = Math.min(size.width, size.height) - 10;
        int x = (size.width - d) / 2;
        int y = (size.height - d) / 2;
        g.fillOval(x, y, d, d);
        g.setColor(Color.blue);
    }
}