1    package npw;
2    
3    import painter.SPainter;
4    import shapes.SCircle;
5    
6    import javax.swing.*;
7    import java.awt.*;
8    import java.util.Random;
9    import java.util.Scanner;
10   
11   public class SimpleDots {
12   
13       public static void main(String[] args) {
14           SwingUtilities.invokeLater(SimpleDots::new);
15       }
16   
17       public SimpleDots() {
18           paintTheImage();
19       }
20   
21       private void paintTheImage() {
22           // Grab the input information
23           int width = getNumber("width");
24           int height = getNumber("height");
25           int dotSpace = getNumber("horizontal space between dots");
26           String color = getColor("color");
27           // Establish the painter
28           SPainter painter = new SPainter("Abstract Gradient", width, height);
29           SCircle dot = new SCircle(5);
30   
31           // Move the painter to the upper left corner to get ready to paint the gradient
32           painter.mfd(height / 2.0);
33           painter.tl();
34           painter.mfd(width / 2.0);
35           painter.tl();
36   
37           // Paint it!
38           paintGradient(painter, dot, height, width, dotSpace, color);
39       }
40   
41       private String getColor(String color) {
42           String nss = JOptionPane.showInputDialog(null, color + "?");
43           Scanner scanner = new Scanner(nss);
44           return scanner.next();
45   
46   
47       }
48   
49   
50       private static int getNumber(String prompt) {
51           String nss = JOptionPane.showInputDialog(null, prompt + "?");
52           Scanner scanner = new Scanner(nss);
53           return scanner.nextInt();
54       }
55   
56       private void paintGradient(SPainter painter, SCircle dot, int height, int width, int dotSpace, String color) {
57           // Calculate the number of columns. We want to fill the screen, but don't want any columns half on the canvas.
58           // A column takes up the horizontal space of a dot's diameter plus the space between it and a neighbor.
59           double colWidth = dot.diameter() + dotSpace;
60           // We don't want a column all the way on the edge on the right side, so subtract 1.
61           int nrOfCols = (int) Math.floor((width / colWidth)) - 1;
62   
63           int cols = 0;
64           while (cols < nrOfCols) {
65               nextCol(painter, dot, dotSpace);
66               paintColumn(painter, dot, height, dotSpace, color);
67               cols = cols + 1;
68           }
69       }
70   
71       private void paintOneDot(SPainter painter, SCircle dot, String color) {
72           painter.setColor(fixedColor(color));
73           painter.paint(dot);
74   
75       }
76   
77       private Color fixedColor(String color) {
78           if (color.equalsIgnoreCase("red")) {
79               return Color.red;
80           } else if (color.equalsIgnoreCase("blue")) {
81               return Color.blue;
82           } else if (color.equalsIgnoreCase("green")) {
83               return Color.green;
84           } else {
85               return Color.black;
86           }
87   
88       }
89   
90       // Dots are spaced more tightly together near the bottom of the canvas.
91       private void paintColumn(SPainter painter, SCircle dot, int height, int dotSpace, String color) {
92           int totalDistanceTraveled = 0;
93   
94           // Paint a column with decreasing distance between dots.
95           while (totalDistanceTraveled < height - (dot.radius() * 3)) {
96               int travel = (int) (dot.diameter() + dotSpace);
97               totalDistanceTraveled = totalDistanceTraveled + travel;
98               painter.mfd(travel);
99               paintOneDot(painter, dot, color);
100          }
101  
102          // Make the method invariant with respect to painter position.
103          painter.mbk(totalDistanceTraveled);
104      }
105  
106      // Moves the painter to the next column.
107      private void nextCol(SPainter painter, SCircle dot, int dotSpace) {
108          painter.tl();
109          painter.mfd(dot.diameter() + dotSpace);
110          painter.tr();
111      }
112  }