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 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 }