1    /* 
2     * A program to paint, centered on the canvas, a circle of randomly 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 HirstSquares {
17   
18       public HirstSquares() {
19           paintTheImage();
20       }
21   
22       private void paintTheImage(){
23           // Get the input information
24           int radius = getNumber("circle radius");
25           int side = getNumber("square side length");
26   
27           // Establish the painter
28           SPainter painter = new SPainter("Circle of Squares", radius*2+50, radius*2+50);
29           painter.setBrushWidth(3);
30           SCircle circle = new SCircle(radius);
31           SSquare square = new SSquare(side);
32   
33           // Paint the squares
34           paintCircleOfSquares(painter, circle, square);
35       }
36   
37       private void paintCircleOfSquares(SPainter painter, SCircle circle, SSquare square){
38           // Position the painter to begin drawing the rows
39           painter.mfd(circle.radius());
40           painter.tr();
41           // Paint the circle of squares
42           double moved = 0;
43           while (moved < circle.diameter()) {
44               double chord = chordLength(circle.radius() - moved, circle);
45               int squares = squaresOnLineCount(chord, square.side());
46               paintRow(painter, square, squares);
47               nextRow(painter, square.side());
48               moved = moved + square.side();
49           }
50           // Make the method invariant with respect to painter position
51           painter.tl();
52           painter.mfd(circle.radius());
53       }
54   
55       // Move to the next row
56       private void nextRow(SPainter painter, double rowHeight){
57           painter.tr();
58           painter.mfd(rowHeight);
59           painter.tl();
60       }
61   
62       // Assumes the painter is at the center of the row to paint, facing right.
63       private void paintRow(SPainter painter, SSquare square, int squaresToPaint){
64           // Move backward 1/2 of the length we're painting to get ready to paint the row.
65           double centerOffset = ( (squaresToPaint * square.side()) / 2) - square.side()/2;
66           painter.mbk(centerOffset);
67   
68           // Paint the row of squares.
69           int painted = 0;
70           while (painted < squaresToPaint){
71               paintOneSquare(painter, square);
72               painter.mfd(square.side());
73               painted = painted + 1;
74           }
75   
76           // Make the method invariant with respect to painter position.
77           painter.mbk(centerOffset + square.side());
78       }
79   
80       private void paintOneSquare(SPainter painter, SSquare square){
81           square.s2();
82           painter.setColor(randomColor());
83           painter.paint(square);
84           painter.setColor(Color.BLACK);
85           painter.draw(square);
86           square.expand(square.side());
87   
88       }
89   
90       private static int squaresOnLineCount(double lineLength, double sideLength){
91           int squares = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1);
92           return squares;
93       }
94   
95       private double chordLength(double yOffset, SCircle circle){
96           double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
97           double chordLength = xLength * 2;
98           return chordLength;
99       }
100  
101      private static int getNumber(String prompt) {
102          String nss = JOptionPane.showInputDialog(null,prompt+"?");
103          Scanner scanner = new Scanner(nss);
104          return scanner.nextInt();
105      }
106  
107      private static Color randomColor() {
108          Random rgen = new Random();
109          int r = rgen.nextInt(256);
110          int g = rgen.nextInt(256);
111          int b = rgen.nextInt(256);
112          return new Color(r,g,b);
113      }
114  
115  
116  
117      public static void main(String[] args) {
118          SwingUtilities.invokeLater(new Runnable() {
119              public void run()
120              {
121                  new HirstSquares();
122              }
123          });
124      }
125  }
126  
127