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 SimpleDots {
17   
18       private void paintTheImage(){
19           // Get the input information
20           int radius = getNumber("circle radius");
21           int side = getNumber("circle radius length");
22           Color color = getColor("color (red, blue, or green)");
23   
24           // Establish the painter
25           SPainter painter = new SPainter("Hirst Dots", radius*2+50, radius*2+50);
26           painter.setColor(color);
27           painter.setBrushWidth(3);
28           SCircle circle = new SCircle(radius);
29           SCircle dot = new SCircle(side);
30   
31           // Paint the dots
32           paintCircleOfDots(painter, circle, dot);
33       }
34   
35       private void paintCircleOfDots(SPainter painter, SCircle circle, SCircle dot){
36           // Position the painter to begin drawing the rows
37           painter.mfd(circle.radius());
38           painter.tr();
39           // Paint the circle of dots
40           double moved = 0;
41           while (moved < circle.diameter()) {
42               double chord = chordLength(circle.radius() - moved, circle);
43               int dots = dotsOnLineCount(chord, dot.radius());
44               paintRow(painter, dot, dots);
45               nextRow(painter, dot.radius());
46               moved = moved + dot.radius();
47           }
48           // Make the method invariant with respect to painter position
49           painter.tl();
50           painter.mfd(circle.radius());
51       }
52   
53       // Move to the next row
54       private void nextRow(SPainter painter, double rowHeight){
55           painter.tr();
56           painter.mfd(rowHeight);
57           painter.tl();
58       }
59   
60       // Assumes the painter is at the center of the row to paint, facing right.
61       private void paintRow(SPainter painter, SCircle dot, int dotsToPaint){
62           // Move backward 1/2 of the length we're painting to get ready to paint the row.
63           double centerOffset = ( (dotsToPaint * dot.radius()) / 2) - dot.radius()/2;
64           painter.mbk(centerOffset);
65   
66           // Paint the row of dots.
67           int painted = 0;
68           while (painted < dotsToPaint){
69               paintOneDot(painter, dot);
70               painter.mfd(dot.radius());
71               painted = painted + 1;
72           }
73   
74           // Make the method invariant with respect to painter position.
75           painter.mbk(centerOffset + dot.radius());
76       }
77   
78       private void paintOneDot(SPainter painter, SCircle dot){
79           dot.s3();
80           painter.paint(dot);
81   
82           dot.x3();
83       }
84   
85       private static int dotsOnLineCount(double lineLength, double sideLength){
86           int dots = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1);
87           return dots;
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 getColor(String prompt) {
103          String nss = JOptionPane.showInputDialog(null, prompt+"?");
104          Scanner scanner = new Scanner(nss);
105          String response = scanner.next();
106          Color color = Color.black;
107          if (response.equalsIgnoreCase("red"))
108          {
109              color = Color.RED;
110          }
111          else if (response.equalsIgnoreCase(("blue")))
112          {
113              color = Color.BLUE;
114          }
115          else if(response.equalsIgnoreCase("green"))
116          {
117              color = Color.GREEN;
118          }
119          return color;
120      }
121  
122      public SimpleDots() {
123          paintTheImage();
124      }
125  
126      public static void main(String[] args) {
127          SwingUtilities.invokeLater(new Runnable() {
128              public void run() {
129                  new SimpleDots();
130              }
131          });
132      }
133  }