How should an Animation class be implemented?

[kiregad]

I've tried to code an Animation class, which creates animations of different pictures following eachother.

Heres what I've come up with:

package grxTest;

import java.awt.*;
import java.util.*;

import javax.swing.ImageIcon;

public class Animation {
	private ArrayList images;
	private int currFrame;
	
	public Animation() {
		images = new ArrayList();
		currFrame = -1;
	}
	
	public void addFrame(Image i) {
		images.add(i);
	}
	
	public static Image loadImage(String s) {
		return new ImageIcon(s).getImage();
	}
	
	public Image getImage() {		
		currFrame++;
		
		if(currFrame == images.size()-1) {
			currFrame = 0;
		}
		
		return (Image)images.get(currFrame);
	}
}

The 3 images are swapping too fast. I know I can sleep the thread, but I dont wanna do that. What can I do to specify that the first image should show for 300 ms, and the nest two ones for 600 ms?

[berkeleybross]

// Not tested

long CurrentTime = System.currentTimeMillis();
while (System.currentTimeMillis() < CurrentTime + 300) {
    // Do nothing
}

Although it would be a lot more sensible to use thread.sleep. How come you are not doing that?

[StormyWaters]

Where exactly are you drawing your animation? This class appears to just hold the images that will be drawn are return the next one to draw.

You could try putting the drawing of the animation in a Timer.

[Norm]

Go look at the Java tutorial. It has a section on using Swing timers with an example program: TumbleItem that does what you're trying to do.

Sorry no URL, I have the tutorial on my computer.

[dinosoep]

long CurrentTime = System.currentTimeMillis();
while (System.currentTimeMillis() < CurrentTime + 300) {
// Do nothing
}

are you nuts :p you are making this thread taking over all the memory over everything else. if you want to do that place between the while
Threading.getCurrentThread().yield(); or something like that

[berkeleybross]

Heh, didnt say it was efficient. :P

[Fubarable]

Heh, didnt say it was efficient. :P

It's not a question of efficiency, but it will likely tie up the main Swing thread, the EDT, and put the whole application to sleep. I think the best solution is Norm's: use a Swing Timer as this is what they're built for. Yield won't help here either.

[kiregad]

The reason I dont wanna use sleep is because I believe it is inefficient. Because if Im making a game, and have like 200 sprites/animations walking around, the game would sleep itself to hell.

This is what I think, but feel free to correct me :)

[dinosoep]

if you are using a game, your probably gonna have multiple threads.
If one sleeps, everything else will stay reactive. The end user won't have a bad experience and sleep isn't ineffecient :p

[kiregad]

But not all computers have the same hardware! So shouldnt we update animations based on real time?