Question

Write a Java program that will output a 640x480 screen pixels, with a diagonal line from each both ends. Please help.

Answer 1

You should have already learned about swing, frames, panels, etc. and so this example should help from:
Publisher : Prentice Hall PTR
Core Java™ 2 Volume I - Fundamentals, Seventh Edition
By Cay S. Horstmann, Gary Cornell

Pub Date : August 17, 2004
ISBN : 0-13-148202-5
Pages : 784


Example 7-4. DrawTest.java
1. import java.awt.*;
2. import java.awt.geom.*;
3. import javax.swing.*;
4.
5. public class DrawTest
6. {
7. public static void main(String[] args)
8. {
9. DrawFrame frame = new DrawFrame();
10. frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
11. frame.setVisible(true);
12. }
13. }
14.
15. /**
16. A frame that contains a panel with drawings
17. */
18. class DrawFrame extends JFrame
19. {
20. public DrawFrame()
21. {
22. setTitle("DrawTest");
23. setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
24.
25. // add panel to frame
26.
27. DrawPanel panel = new DrawPanel();
28. add(panel);
29. }
30.
31. public static final int DEFAULT_WIDTH = 400;
32. public static final int DEFAULT_HEIGHT = 400;
33. }
34.
35. /**
36. A panel that displays rectangles and ellipses.
37. */
38. class DrawPanel extends JPanel
39. {
40. public void paintComponent(Graphics g)
41. {
42. super.paintComponent(g);
43. Graphics2D g2 = (Graphics2D) g;
44.
45. // draw a rectangle
46.
47. double leftX = 100;
48. double topY = 100;
49. double width = 200;
50. double height = 150;
51.
52. Rectangle2D rect = new Rectangle2D.Double(leftX, topY, width, height);
53. g2.draw(rect);
54.
55. // draw the enclosed ellipse
56.
57. Ellipse2D ellipse = new Ellipse2D.Double();
58. ellipse.setFrame(rect);
59. g2.draw(ellipse);
60.
61. // draw a diagonal line
62.
63. g2.draw(new Line2D.Double(leftX, topY, leftX + width, topY + height));
64.
65. // draw a circle with the same center
66.
67. double centerX = rect.getCenterX();
68. double centerY = rect.getCenterY();
69. double radius = 150;
70.
71. Ellipse2D circle = new Ellipse2D.Double();
72. circle.setFrameFromCenter(centerX, centerY, centerX + radius, centerY + radius);
73. g2.draw(circle);
74. }
75. }

Answer 2

You just nailed it! Thank you so much espex!

Answer 3

You're welcome.