CS1 Standard Demo Page

/*
 * A program to paint a given number of concentric squares.
 */

package npw;

import painter.SPainter;
import shapes.SSquare;
import java.awt.Color;
import javax.swing.*;
import java.util.Scanner;

public class Stella {
    private void paintTheImage() {
        int number = getNumber("Number of concentric squares");
        int shrink = 700 / number;
        SPainter painter = new SPainter("Stella", 800, 800);
        SSquare square = new SSquare(700);
        Color one = randomColor();
        Color two = randomColor();

        int i = 0;
        while (i < number) {
            if (i % 2 == 0) {
                painter.setColor(one);
            } else {
                painter.setColor(two);
            }
            painter.paint(square);
            square.resetSide((int) (square.side() - shrink));
            i = i + 1;
        }
    }

    private static int getNumber(String prompt) {
        String scanner = JOptionPane.showInputDialog(null, prompt + "?");
        Scanner nss= new Scanner(scanner);
        return nss.nextInt();
    }

    private static Color randomColor() {
        int rv = (int) (Math.random() * 256);
        int gv = (int) (Math.random() * 256);
        int bv = (int) (Math.random() * 256);
        return new Color(rv, gv, bv);
    }

    public Stella() {
        paintTheImage();
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() { new Stella(); }
        });
    }
}