1    /* 
2     *A program to paint, centered on the canvas, a circle of randomlt colored, black-framed squares 
3     */
4    
5    package npw;
6    
7            import painter.SPainter;
8            import shapes.SCircle;
9            import shapes.SSquare;
10   
11           import javax.swing.*;
12           import java.awt.*;
13           import java.util.Random;
14           import java.util.Scanner;
15   
16   public class CircleOfSquares {
17   
18       private void paintTheImage () {
19           //GEt the input info
20           int radius = getNumber("circle radius");
21           int side = getNumber("square side length");
22   
23           //Establish the painter
24           SPainter painter = new SPainter("Circle of Square", radius * 2 + 50, radius * 2 + 50);
25           painter.setBrushWidth(3);
26           SCircle circle = new SCircle(radius);
27           SSquare square = new SSquare(side);
28   
29           //Paint the squares
30           paintCircleOfSquares(painter, circle, square);
31       }
32       private void paintCircleOfSquares(SPainter painter, SCircle circle, SSquare square) {
33           //Position the painter to begin drawing the rows
34           painter.mfd(circle.radius());
35           painter.tr();
36           // Paint the circle of squares
37           double moved = 0;
38           while (moved < circle.diameter()) {
39               double chord = chordLength(circle.radius() - moved, circle);
40               int squares = squareOnLineCount(chord, square.side());
41               paintRow(painter, square, squares);
42               nextRow(painter, square.side());
43               moved = moved + square.side();
44           }
45   
46           //Make the method invariant with respect to painter position
47           painter.tl();
48           painter.mfd(circle.radius());
49       }
50       //Move to the next row
51       private void nextRow(SPainter painter, double rowHeight) {
52           painter.tr();
53           painter.mfd(rowHeight);
54           painter.tl();
55       }
56   
57       //Assumes the painter is at the center of the row to paint, facing right.
58       private void paintRow(SPainter painter, SSquare square, int squaresToPaint){
59           //Move backward 1/2 of the length we're painting to get ready to paint the row.
60           double centerOffset = ((squaresToPaint * square.side())/2) - square.side()/2;
61           painter.mbk(centerOffset);
62   
63           //Paint the row of squares.
64           int painted = 0;
65           while (painted < squaresToPaint) {
66               paintOneSquare(painter, square);
67               painter.mfd(square.side());
68               painted = painted + 1;
69           }
70   
71           //Make the method invariant with respect to painter position.
72           painter.mbk(centerOffset + square.side());
73       }
74   
75       private void paintOneSquare(SPainter painter, SSquare square) {
76           painter.setColor(randomColor());
77           painter.paint(square);
78           painter.setColor(Color.BLACK);
79           painter.draw(square);
80       }
81   
82       private static int squareOnLineCount(double lineLength, double sideLength) {
83           int squuares = ((int)Math.ceil((lineLength - sideLength) / sideLength) + 1);
84           return squuares;
85       }
86   
87       private double chordLength(double yOffset, SCircle circle){
88           double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
89           double chordLength = xLength * 2;
90           return chordLength;
91       }
92   
93       private static int getNumber(String prompt) {
94           String nss = JOptionPane.showInputDialog(null,prompt + "?");
95           Scanner scanner = new Scanner(nss);
96           return scanner.nextInt();
97       }
98   
99       private static Color randomColor() {
100          Random rgen = new Random();
101          int r = rgen.nextInt(256);
102          int g = rgen.nextInt(256);
103          int b = rgen.nextInt(256);
104          return new Color(r,g,b);
105      }
106  
107      public CircleOfSquares() {
108          paintTheImage();
109      }
110  
111      public static void main(String[] args) {
112          SwingUtilities.invokeLater(new Runnable() {
113              @Override
114              public void run() {
115                  new CircleOfSquares();
116              }
117          });
118      }
119  }
120