SimpleDots.java
package npw;

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

public class SimpleDots {

    private void paintTheImage() {
        int radius = getNumber("circle radius");
        int diameter = getNumber("dot diameter length");
        String color = getColor("Color");

        SPainter painter = new SPainter("Circle of Dots", radius * 2 + 50, radius * 2 + 50);
        painter.setBrushWidth(3);
        SCircle circle = new SCircle(radius);
        SCircle dot = new SCircle(diameter);

        if (color.equals("red")) {
            painter.setColor(Color.red);
        } else if (color.equals("green")) {
            painter.setColor(Color.green);
        } else if (color.equals("blue")) {
            painter.setColor(Color.blue);
        } else {
            painter.setColor(Color.black);
        }

        paintCircleOfDots(painter, circle, dot);
    }

    private void paintCircleOfDots(SPainter painter, SCircle circle, SCircle dot) {

        painter.mfd(circle.radius());
        painter.tr();

        double moved = 0;
        while (moved < circle.diameter()) {
            double chord = chordLength(circle.radius() - moved, circle);
            int dots = dotsOnLineCount(chord, dot.diameter());
            paintRow(painter, dot, dots);
            nextRow(painter, dot.diameter());
            moved = moved + dot.diameter();
        }

        painter.tl();
        painter.mfd(circle.radius());
    }

    private void nextRow(SPainter painter, double rowHeight){
        painter.tr();
        painter.mfd(rowHeight);
        painter.tl();
    }

    private void paintRow(SPainter painter, SCircle dot, int dotsToPaint){

        double centerOffset = ( (dotsToPaint * dot.diameter()) / 2) - dot.diameter()/2;
        painter.mbk(centerOffset);

        int painted = 0;
        while (painted < dotsToPaint){
            paintOnedot(painter, dot);
            painter.mfd(dot.diameter());
            painted = painted + 1;
        }

        painter.mbk(centerOffset + dot.diameter());
    }

    private void paintOnedot(SPainter painter, SCircle dot){
        dot.s2();
        painter.paint(dot);
        dot.x2();
    }

    private static int dotsOnLineCount(double lineLength, double diameterLength){
        int dots = ( (int)Math.ceil( ( lineLength - diameterLength ) / diameterLength ) + 1);
        return dots;
    }

    private double chordLength(double yOffset, SCircle circle){
        double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
        double chordLength = xLength * 2;
        return chordLength;
    }

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

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

    public SimpleDots() {
        paintTheImage();
    }

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