1    /* 
2    * A program to paint, centered on the canvas, a circle of randomly colored, black-framed square 
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       private void paintTheImage(){
19           // Get the input information
20           int radius = getNumber("circle radius");
21           int side = getNumber("square side length");
22   
23           // Establish the painter
24           SPainter painter = new SPainter("Hirst Squares", 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   
33       private void paintCircleOfSquares(SPainter painter, SCircle circle, SSquare square){
34           // Position the painter to begin drawing the rows
35           painter.mfd(circle.radius());
36           painter.tr();
37           // Paint the circle of squares
38           double moved = 0;
39           while (moved < circle.diameter()) {
40               double chord = chordLength(circle.radius() - moved, circle);
41               int squares = squaresOnLineCount(chord, square.side());
42               paintRow(painter, square, squares);
43               nextRow(painter, square.side());
44               moved = moved + square.side();
45           }
46           // Make the method invariant with respect to painter position
47           painter.tl();
48           painter.mfd(circle.radius());
49       }
50   
51       // Move to the next row
52       private void nextRow(SPainter painter, double rowHeight){
53           painter.tr();
54           painter.mfd(rowHeight);
55           painter.tl();
56       }
57   
58       // Assumes the painter is at the center of the row to paint, facing right.
59       private void paintRow(SPainter painter, SSquare square, int squaresToPaint){
60           // Move backward 1/2 of the length we're painting to get ready to paint the row.
61           double centerOffset = ( (squaresToPaint * square.side()) / 2) - square.side()/2;
62           painter.mbk(centerOffset);
63   
64           // Paint the row of squares.
65           int painted = 0;
66           while (painted < squaresToPaint){
67               paintOneSquare(painter, square);
68               painter.mfd(square.side());
69               painted = painted + 1;
70           }
71   
72           // Make the method invariant with respect to painter position.
73           painter.mbk(centerOffset + square.side());
74       }
75   
76       private void paintOneSquare(SPainter painter, SSquare square){
77           square.s2();
78           painter.setColor(randomColor());
79           painter.paint(square);
80           painter.setColor(Color.BLACK);
81           painter.draw(square);
82           square.x2();
83   
84       }
85   
86       private static int squaresOnLineCount(double lineLength, double sideLength){
87           int squares = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1);
88           return squares;
89       }
90   
91       private double chordLength(double yOffset, SCircle circle){
92           double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
93           double chordLength = xLength * 2;
94           return chordLength;
95       }
96   
97       private static int getNumber(String prompt) {
98           String nss = JOptionPane.showInputDialog(null,prompt+"?");
99           Scanner scanner = new Scanner(nss);
100          return scanner.nextInt();
101      }
102  
103      private static Color randomColor() {
104          Random rgen = new Random();
105          int r = rgen.nextInt(256);
106          int g = rgen.nextInt(256);
107          int b = rgen.nextInt(256);
108          return new Color(r,g,b);
109      }
110  
111      public HirstSquares() {
112          paintTheImage();
113      }
114  
115      public static void main(String[] args) {
116          SwingUtilities.invokeLater(new Runnable() {
117              public void run() {
118                  new HirstSquares();
119              }
120          });
121      }
122  }