libgdx Stage.dispose() does not detach actors immediately

1
votes

I work with libgdx and I have this situation where I use a Stage with threeActors attached. When the act() method is being called for the stage, each of the actors' act() method is being called. This is the default behavior and it's correct.

But, if i dispose the scene in the second's actor act() method, then the act() method of the third actor is still being called. I would not have expected this behavior. It's like this actor is not being detached immediately after the dispose() method is called on the stage. This last call on the third actor is problematic for me because i get an exception and i don't know how to avoid it. If the third actor's act() method would not be called one last time before the scene is actually disposed it would be great.

Do you have any idea how could i avoid this?

I find it difficult to change my game design because in my case the second actor is an enemy and the third actor is a defense tower. When the enemy dies, i dispose the scene in order to show the game over screen. But the tower still acts in the background...

2
libgdxdisposeactorstagedetach
This is the designed behavior of Stage. It guarantees that every actor's act method is called once in a frame, regardless of what other actors are doing. I think in most cases this is the most useful behavior. Maybe you could share what is happening in your tower's act method that causes an exception. - Tenfour04
Thanks, i believe a redesign of part of my application could avoid this. Just that i find it strange that there still is an actor acting on the stage even after it's been disposed. I don't think there's a clean way to handle this. - linu

2 Answers

0
votes

Try using actor.remove() or stage.clear()

0
votes

Instead of changing screens/disposing your stage directly when your enemies die, you could pass in whatever class is controlling your stage as an argument to your actors. When your actor dies you could, for example set a boolean in the class holding your stage to transition, then after the stage.act() is called, check if you need to make a transition, then safely dispose of the stage. It's not very elegant but it's sure to work. There are also many ways you could go about implementing transitions called from outside objects. A boolean might be very limiting because you can't tell your game what screen you want to transition to, so you might want to implement some sort of Runnable implementation. There are many ways.

Just an idea. I hope this helps.