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 javax.swing.*;
10   import java.awt.*;
11   import java.util.Scanner;
12   
13   public class SimpleDots {
14   
15       private void paintTheImage(){
16           // Get the input information
17           int radius = getNumber("circle radius");
18           int radius2 = getNumber("dot radius");
19           Color circColor = getColor("dot color");
20           // Establish the painter
21           SPainter painter = new SPainter("Circle of Squares", radius*2+50, radius*2+50);
22           painter.setBrushWidth(3);
23           SCircle circle = new SCircle(radius);
24           SCircle SmallCircle = new SCircle(radius2);
25   
26           // Paint the squares
27           paintSimpleDots(painter, circle, SmallCircle, circColor);
28       }
29   
30       private void paintSimpleDots(SPainter painter, SCircle circle, SCircle SmallCircle, Color circColor){
31           // Position the painter to begin drawing the rows
32           painter.mfd(circle.radius());
33           painter.tr();
34           // Paint the circle of squares
35           double moved = 0;
36           while (moved < circle.diameter()) {
37               double chord = chordLength(circle.radius() - moved, circle);
38               int squares = dotsOnLineCount(chord, SmallCircle.radius());
39               paintRow(painter, SmallCircle, squares, circColor);
40               nextRow(painter, SmallCircle.radius());
41               moved = moved + SmallCircle.radius();
42           }
43           // Make the method invariant with respect to painter position
44           painter.tl();
45           painter.mfd(circle.radius());
46       }
47   
48       // Move to the next row
49       private void nextRow(SPainter painter, double rowHeight){
50           painter.tr();
51           painter.mfd(rowHeight);
52           painter.tl();
53       }
54   
55       // Assumes the painter is at the center of the row to paint, facing right.
56       private void paintRow(SPainter painter, SCircle SmallCircle, int dotsToPaint, Color circColor){
57           // Move backward 1/2 of the length we're painting to get ready to paint the row.
58           double centerOffset = ( (dotsToPaint * SmallCircle.radius()) / 2) - SmallCircle.radius()/2;
59           painter.mbk(centerOffset);
60   
61           // Paint the row of squares.
62           int painted = 0;
63           while (painted < dotsToPaint){
64               paintOneDot(painter, SmallCircle, circColor);
65               painter.mfd(SmallCircle.radius());
66               painted = painted + 1;
67           }
68   
69           // Make the method invariant with respect to painter position.
70           painter.mbk(centerOffset + SmallCircle.radius());
71       }
72   
73       private void paintOneDot(SPainter painter, SCircle SmallCircle, Color circColor){
74           SmallCircle.s2();SmallCircle.s2();
75           painter.setColor(circColor);
76           painter.paint(SmallCircle);
77           SmallCircle.x2();SmallCircle.x2();
78       }
79   
80       private static int dotsOnLineCount(double lineLength, double sideLength){
81           int dots = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1);
82           return dots;
83       }
84   
85       private double chordLength(double yOffset, SCircle circle){
86           double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
87           double chordLength = xLength * 2;
88           return chordLength;
89       }
90   
91       private static int getNumber(String prompt) {
92           String nss = JOptionPane.showInputDialog(null,prompt+"?");
93           Scanner scanner = new Scanner(nss);
94           return scanner.nextInt();
95       }
96       private static Color getColor(String prompt) {
97           String color = JOptionPane.showInputDialog(null,prompt+"color?");
98           if(color.equalsIgnoreCase("BLUE")){
99               return Color.blue;
100          } else if (color.equalsIgnoreCase("RED")){
101              return Color.red;
102          } else if (color.equalsIgnoreCase("GREEN")){
103              return Color.green;
104          } else {
105              return Color.BLACK;
106          }
107      }
108  
109      public SimpleDots() {
110          paintTheImage();
111      }
112  
113      public static void main (String[] args) {
114          SwingUtilities.invokeLater(new Runnable() {
115              public void run() {
116                  new SimpleDots();
117              }
118          });
119      }
120  }