1    package npw;
2    import painter.SPainter;
3    import shapes.SCircle;
4    import shapes.SSquare;
5    
6    import javax.swing.*;
7    import java.awt.*;
8    import java.util.Random;
9    import java.util.Scanner;
10   public class CircleOfSquares {
11   
12   
13   
14   
15   
16           private void paintTheImage(){
17               // Get the input information
18               int radius = getNumber("circle radius");
19               int side = getNumber("square side length");
20   
21               // Establish the painter
22               SPainter painter = new SPainter("Circle of Squares", radius*2+50, radius*2+50);
23               painter.setBrushWidth(3);
24               SCircle circle = new SCircle(radius);
25               SSquare square = new SSquare(side);
26   
27               // Paint the squares
28               paintCircleOfSquares(painter, circle, square);
29           }
30   
31           private void paintCircleOfSquares(SPainter painter, SCircle circle, SSquare square){
32               // Position the painter to begin drawing the rows
33               painter.mfd(circle.radius());
34               painter.tr();
35               // Paint the circle of squares
36               double moved = 0;
37               while (moved < circle.diameter()) {
38                   double chord = chordLength(circle.radius() - moved, circle);
39                   int squares = squaresOnLineCount(chord, square.side());
40                   paintRow(painter, square, squares);
41                   nextRow(painter, square.side());
42                   moved = moved + square.side();
43               }
44               // Make the method invariant with respect to painter position
45               painter.tl();
46               painter.mfd(circle.radius());
47           }
48   
49           // Move to the next row
50           private void nextRow(SPainter painter, double rowHeight){
51               painter.tr();
52               painter.mfd(rowHeight);
53               painter.tl();
54           }
55   
56           // Assumes the painter is at the center of the row to paint, facing right.
57           private void paintRow(SPainter painter, SSquare square, int squaresToPaint){
58               // Move backward 1/2 of the length we're painting to get ready to paint the row.
59               double centerOffset = ( (squaresToPaint * square.side()) / 2) - square.side()/2;
60               painter.mbk(centerOffset);
61   
62               // Paint the row of squares.
63               int painted = 0;
64               while (painted < squaresToPaint){
65                   paintOneSquare(painter, square);
66                   painter.mfd(square.side());
67                   painted = painted + 1;
68               }
69   
70               // Make the method invariant with respect to painter position.
71               painter.mbk(centerOffset + square.side());
72           }
73   
74           private void paintOneSquare(SPainter painter, SSquare square){
75               painter.setColor(randomColor());
76               painter.paint(square);
77               painter.setColor(Color.BLACK);
78               painter.draw(square);
79           }
80   
81           private static int squaresOnLineCount(double lineLength, double sideLength){
82               int squares = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1);
83               return squares;
84           }
85   
86           private double chordLength(double yOffset, SCircle circle){
87               double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
88               double chordLength = xLength * 2;
89               return chordLength;
90           }
91   
92           private static int getNumber(String prompt) {
93               String nss = JOptionPane.showInputDialog(null,prompt+"?");
94               Scanner scanner = new Scanner(nss);
95               return scanner.nextInt();
96           }
97   
98           private static Color randomColor() {
99               Random rgen = new Random();
100              int r = rgen.nextInt(256);
101              int g = rgen.nextInt(256);
102              int b = rgen.nextInt(256);
103              return new Color(r,g,b);
104          }
105  
106          public CircleOfSquares() {
107              paintTheImage();
108          }
109  
110          public static void main(String[] args) {
111              SwingUtilities.invokeLater(new Runnable() {
112                  public void run() {
113                      new CircleOfSquares();
114                  }
115              });
116          }
117      }
118  
119  
120  
121  
122  
123  
124  
125  
126  
127  
128  
129  
130  
131  
132  
133  
134