1    /* 
2     * A program to paint, centered on the canvas, a circle of  colored dots that are spaced apart. The program prompts 
3     * the user for red, green, or blue circles. If they dont choose, black is the color selected. 
4     */
5    
6    
7    package npw;
8    
9    import painter.SPainter;
10   import shapes.SCircle;
11   import shapes.SSquare;
12   import javax.swing.JOptionPane;
13   import java.awt.Color;
14   import javax.swing.*;
15   
16   import java.util.Random;
17   import java.util.Scanner;
18   
19   public class SimpleDots{
20   
21       private void paintTheImage(){
22           // Get the input information
23           int radius = getNumber("circle radius");
24           int radius1 = getNumber("dot radius length");
25   
26           // Establish the painter
27           SPainter painter = new SPainter("SimpleDots", radius*2+50, radius*2+50);
28           painter.setBrushWidth(3);
29           SCircle circle = new SCircle(radius);
30           SCircle dot = new SCircle(radius1);
31   
32   
33           // Paint the squares
34           paintCircleOfDots(painter, circle, dot);
35       }
36   
37   
38       private void paintCircleOfDots(SPainter painter, SCircle circle, SCircle dot){
39           // Position the painter to begin drawing the rows
40           painter.mfd(circle.radius());
41           painter.tr();
42   
43   
44           // Paint the circle of dots
45           double moved = 0;
46           while (moved < circle.diameter()) {
47               double chord = chordLength(circle.radius() - moved, circle);
48               int dots = DotsOnLineCount(chord, dot.diameter());
49               paintRow(painter, dot, dots);
50               nextRow(painter, dot.diameter());
51               moved = moved + dot.diameter();
52           }
53           // Make the method invariant with respect to painter position
54           painter.tl();
55           painter.mfd(circle.radius());
56   
57       }
58   
59       // Move to the next row
60       private void nextRow(SPainter painter, double rowHeight){
61           painter.tr();
62           painter.mfd(rowHeight);
63           painter.tl();
64   
65   
66       }
67   
68       // Assumes the painter is at the center of the row to paint, facing right.
69       private void paintRow(SPainter painter, SCircle dot, int DotsToPaint){
70           // Move backward 1/2 of the length we're painting to get ready to paint the row.
71           double centerOffset = ( (DotsToPaint * dot.diameter()) / 2) - dot.diameter()/2;
72           painter.mbk(centerOffset);
73   
74   
75           // Paint the row of dots
76           int painted = 0;
77           while (painted < DotsToPaint){
78               paintOneCircle(painter, dot);
79               painter.mfd(dot.diameter());
80               painted = painted + 1;
81   
82           }
83   
84           // Make the method invariant with respect to painter position.
85           painter.mbk(centerOffset + dot.diameter());
86       }
87   
88       private void paintOneCircle(SPainter painter, SCircle dot){
89           dot.shrink(dot.radius() * 0.50);
90           choiceColor(painter);
91           painter.paint(dot);
92           dot.expand(dot.radius()); ///Needed for invariance
93       }
94   
95       private static int DotsOnLineCount(double lineLength, double dotDiameter){
96           int dot = ( (int)Math.ceil( ( lineLength - dotDiameter ) / dotDiameter ) + 1);
97           return dot;
98       }
99   
100      private double chordLength(double yOffset, SCircle circle){
101          double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
102          double chordLength = xLength * 2;
103          return chordLength;
104      }
105  
106      private static int getNumber(String prompt) {
107          String nss = JOptionPane.showInputDialog(null,prompt+"?");
108          Scanner scanner = new Scanner(nss);
109          return scanner.nextInt();
110      }
111      private static String getColor(String prompt) {
112          String nss = JOptionPane.showInputDialog (null, prompt+ "?");
113          Scanner scanner = new Scanner(nss);
114          return scanner.next();
115  
116      }
117      String inputColor = getColor("dot color(red, green, blue)");
118      private void choiceColor(SPainter painter) {
119  
120          if (inputColor.equalsIgnoreCase("red")) {
121              painter.setColor(Color.RED);
122          } else if (inputColor.equalsIgnoreCase("green")) {
123              painter.setColor(Color.GREEN);
124          } else if (inputColor.equalsIgnoreCase("blue")) {
125              painter.setColor(Color.BLUE);
126          } else {
127              painter.setColor(Color.BLACK);
128          }
129      }
130  
131      public SimpleDots() {
132          paintTheImage();
133      }
134  
135      public static void main(String[] args) {
136          SwingUtilities.invokeLater(new Runnable() {
137              public void run() {
138                  new SimpleDots();
139              }
140          });
141      }
142  }
143