Prentice.Hall.Introduction.to.Java.Programming,.Brief.Version.9th.(2014).[sharethefiles.com]

13.8 Case Study: The MessagePanel Class 497
The MessagePanel class is implemented in Listing 13.8. The program seems long but is
actually simple, because most of the methods are get and set methods, and each method is
relatively short and easy to read.
LISTING 13.8
MessagePanel.java
1 import java.awt.FontMetrics;
2 import java.awt.Dimension;
3 import java.awt.Graphics;
4 import javax.swing.JPanel;
5
6 public class MessagePanel extends JPanel {
7 /** The message to be displayed */
8 private String message = "Welcome to Java";
9
10 /** The x-coordinate where the message is displayed */
11 private int xCoordinate = 20;
12
13 /** The y-coordinate where the message is displayed */
14 private int yCoordinate = 20;
15
16 /** Indicate whether the message is displayed in the center */
17 private boolean centered;
18
19 /** The interval for moving the message horizontally
20 * and vertically */
21 private int interval = 10;
22
23 /** Construct with default properties */
24 public MessagePanel() {
25 }
26
27 /** Construct a message panel with a specified message */
28 public MessagePanel(String message) {
29 this.message = message;
30 }
31
32 /** Return message */
33 public String getMessage() {
34 return message;
35 }
36
37 /** Set a new message */
38 public void setMessage(String message) {
39 this.message = message;
40
41
repaint();
}
42
43 /** Return xCoordinator */
44 public int getXCoordinate() {
45 return xCoordinate;
46 }
47
48 /** Set a new xCoordinator */
49 public void setXCoordinate(int x) {
50 this.xCoordinate = x;
51 repaint();
52 }
53
54 /** Return yCoordinator */
repaint panel
repaint panel