1    /* 
2    A program to paint, centered on a canvas, a circle of randomly colored, black-framed squares spaced from each other. 
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 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       private static int squaresOnLineCount(double lineLength, double sideLength){
86           int squares = ((int)Math.ceil((lineLength-sideLength)/sideLength)+1);
87           return squares;
88       }
89   
90       private double chordLength(double yOffset, SCircle circle){
91           double xLength=Math.sqrt(Math.pow(circle.radius(),2)-Math.pow(yOffset,2));
92           double chordLength=xLength*2;
93           return chordLength;
94       }
95   
96       private static int getNumber(String prompt) {
97           String nss = JOptionPane.showInputDialog(null,prompt+"?");
98           Scanner scanner = new Scanner(nss);
99           return scanner.nextInt();
100      }
101  
102      private static Color randomColor() {
103          Random rgen = new Random();
104          int r = rgen.nextInt(256);
105          int g = rgen.nextInt(256);
106          int b = rgen.nextInt(256);
107          return new Color(r,g,b);
108      }
109  
110      public HirstSquares(){
111          paintTheImage();
112      }
113  
114      public static void main(String[] args) {
115          SwingUtilities.invokeLater(new Runnable() {
116              public void run() {
117                  new HirstSquares();
118              }
119          });
120      }
121  }
122