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       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("Circle of 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           paintHirstSquares(painter, circle, square);
31       }
32   
33       private void paintHirstSquares(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   
87       private static int squaresOnLineCount(double lineLength, double sideLength){
88           int squares = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1);
89           return squares;
90       }
91   
92       private double chordLength(double yOffset, SCircle circle){
93           double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
94           double chordLength = xLength * 2;
95           return chordLength;
96       }
97   
98       private static int getNumber(String prompt) {
99           String nss = JOptionPane.showInputDialog(null,prompt+"?");
100          Scanner scanner = new Scanner(nss);
101          return scanner.nextInt();
102      }
103  
104      private static Color randomColor() {
105          Random color = new Random();
106          int r = color.nextInt(256);
107          int g = color.nextInt(256);
108          int b = color.nextInt(256);
109          return new Color(r,g,b);
110      }
111  
112      public HirstSquares() {
113          paintTheImage();
114      }
115  
116      public static void main(String[] args) {
117          SwingUtilities.invokeLater(new Runnable() {
118              public void run() {
119                  new SimpleDots();
120              }
121          });
122      }
123  }
124