Problem with Thread.sleep() and repaint()!!!

[chrishans]

Hi, I'm working on my own version of the Snake game and I have a problem. I want that when "the Snake" collides with itself, change its color to red, wait 1 or 2 seconds and reset the game. For this I used Thread.sleep, but it does not work as I want. First it waits x time, then changes the color, and almost instantaneously restarts the game.

Here's the code:

public void paintComponent(Graphics g) {
		super.paintComponent(g);
		g.setColor(Color.gray);
		g.fillRect(0, 0, 500, 500);
		try {
			Thread.sleep(t);
		} catch (InterruptedException p) {
			p.printStackTrace();
		}
		if (k != 0 && !over) {
			switch (k) {
			case 1:
				xa = 10;
				ya = 0;
				break;

			case 2:
				xa = -10;
				ya = 0;
				break;

			case 3:
				xa = 0;
				ya = 10;
				break;
			case 4:
				xa = 0;
				ya = -10;
				break;
			}
			puntos.poll();
			puntos.addLast(new Point(puntos.getLast().x + xa,
					puntos.getLast().y + ya));
			food(g);
			for (z = puntos.size() - 2; z > 0; z--) {
				if (puntos.getLast().x == puntos.get(z).x
						&& puntos.getLast().y == puntos.get(z).y) {
					over = true;
					System.out.println("PERDISTE");
				}
			}
		}
		if (over) {
			System.out.println("OVER TRUE");
			for (i = 0; i < puntos.size(); i++) {
				g.setColor(Color.red);
				g.fillRect(puntos.get(i).x, puntos.get(i).y, 10, 10);
				g.setColor(Color.black);
				g.drawRect(puntos.get(i).x, puntos.get(i).y, 10, 10);
			}
			try {
				Thread.sleep(1500);
				init();
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			
		} else if (!over) {
			System.out.println("OVER FALSE");
			for (i = 0; i < puntos.size(); i++) {

				g.setColor(Color.green);
				g.fillRect(puntos.get(i).x, puntos.get(i).y, 10, 10);
				g.setColor(new Color(67, 135, 22));
				g.fillRect(puntos.getLast().x, puntos.getLast().y, 10, 10);
				g.setColor(Color.black);
				g.drawRect(puntos.get(i).x, puntos.get(i).y, 10, 10);
			}
			paintfood(g);
			repaint();
		}


	}

- Init (): what it does is reset the values ​​of variables, and so on. and then repaint ();
-food () and paintfood () are for the food of the Snake.
- "points" is the list containing the positions of each square of Snake

I think the problem is in how I used Thread.sleep () and where I put it, I hope you can help!
Thank you!

[KevinWorkman]

Do NOT call Thread.sleep() while on the EDT. Use a Swing Timer to accomplish this instead.

[doWhile]

a) Never call Thread.sleep in the paintComponent method - this is called to from the EDT and will result in your component not updating until the sleep is complete b) Never call repaint from within paintComponent, as repaint basically queue's up another call paintComponent. If you want to do animation, then use a swing Timer or a separate thread (if the latter, make sure calls to Swing components get placed on the EDT).

[chrishans]

Fine, but how do I use a Timer? I've been looking on the web, but I can't find anything I can understand. By the way, I'm a begginer and all my knowledge is taken from tutorials, videos, etc., so I tried to use everything I remembered. I'd never heard about a Swing Timer!
Thanks again!

[KevinWorkman]

First result for googling "java swing timer": How to Use Swing Timers (The Java™ Tutorials > Creating a GUI With JFC/Swing > Using Other Swing Features)

[Fubarable]

Fine, but how do I use a Timer? I've been looking on the web, but I can't find anything I can understand. By the way, I'm a begginer and all my knowledge is taken from tutorials, videos, etc., so I tried to use everything I remembered. I'd never heard about a Swing Timer!
Thanks again!

Rather than tell us you don't understand Swing Timers, which is an unanswerable statement, not a question, better to tell us what you've read in the tutorials and ask specific questions about the tutorial content that you don't understand.

[chrishans]

I finally worked it out. Thanks for your help!!

But I have another question: How can I put a JLabel on the JPanel? It would show the score? I tried adding the JLabel to the JPanel, but I can't see it!

Thanks again!

PS: Do I have to start a new thread for this question?

[Fubarable]

PS: Do I have to start a new thread for this question?

Yes, it probably it would be best if you did, as this is a completely new problem, one that will require that you show us your new code.

Congrats on solving the original problem!