1 package npw; 2 /* 3 * A program to paint, centered on the canvas, a circle of randomly colored, black-framed squares 4 * In this program, we will add spaces between each square 5 */ 6 7 import painter.SPainter; 8 import shapes.SCircle; 9 import shapes.SSquare; 10 import javax.swing.*; 11 import java.awt.*; 12 import java.util.Random; 13 import java.util.Scanner; 14 15 public class HirstSquares { 16 private void paintTheImage(){ 17 // Get the input info 18 int radius = getNumber("circle radius"); 19 int side = getNumber("square side length"); 20 21 // Establish a 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 paintHirstSquares(painter, circle, square); 29 } 30 31 private void paintHirstSquares(SPainter painter, SCircle circle, SSquare square){ 32 // Position the painter to begin drawing 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 // Invariance 45 painter.tl(); 46 painter.mfd(circle.radius()); 47 } 48 49 // Move to 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 square.s2(); 76 painter.setColor(randomColor()); 77 painter.paint(square); 78 painter.setColor(Color.BLACK); 79 painter.draw(square); 80 square.x2(); 81 } 82 83 private static int squaresOnLineCount(double lineLength, double sideLength){ 84 int squares = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1); 85 return squares; 86 } 87 88 private double chordLength(double yOffset, SCircle circle){ 89 double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2)); 90 double chordLength = xLength * 2; 91 return chordLength; 92 } 93 94 private static int getNumber(String prompt) { 95 String nss = JOptionPane.showInputDialog(null,prompt+"?"); 96 Scanner scanner = new Scanner(nss); 97 return scanner.nextInt(); 98 } 99 100 private static Color randomColor() { 101 Random rgen = new Random(); 102 int r = rgen.nextInt(256); 103 int g = rgen.nextInt(256); 104 int b = rgen.nextInt(256); 105 return new Color(r,g,b); 106 } 107 108 public HirstSquares() { 109 paintTheImage(); 110 } 111 112 public static void main(String[] args) { 113 SwingUtilities.invokeLater(new Runnable() { 114 public void run() { 115 new HirstSquares(); 116 } 117 }); 118 } 119 } 120