Java Reference
In-Depth Information
The the
MouseSprite
class, shown in Listing 10-8, draws each of the four sprites in turn.
Conceptually, it is similar to the
Firework
class, in that it draws its pieces on the screen and then
announces that it's done, so that the class holding a reference to it can let that reference go, which lets
the system garbage collect the now useless
MouseSprite
object.
Listing 10-8. The MouseSprite class
package com.bryantcs.examples.animation;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.ImageObserver;
import javax.swing.JPanel;
public class MouseSprite {
private int spriteX, spriteY, step;
private boolean done = false;
Image[] spriteImages= new Image[4];
JPanel spritePanel;
MouseSprite(int x, int y, Image[] images, JPanel panel) {
spriteX = x;
spriteY = y;
step = 0;
spriteImages = images;
spritePanel = panel;
}
void draw(Graphics g) {
ImageObserver observer = spritePanel;
if (step < 4) {
g.drawImage(spriteImages[step], spriteX, spriteY, observer);
step++;
} else {
done = true;
}
}
public boolean isDone() {
return done;
}
}
Figure 10-5 shows the MouseSprite program.
