CODEWITHSUNDEEP
javaandroidlibgdx
ploosu2
ploosu2

Reputation: 433

Libgdx on desktop, how to handle disposing when window is closed

I'm using libgdx (com.badlogic.gdx.Game and Screens and that stuff) to make a game. I have the following problem: on desktop, when I close the window (from the cross on top), of course the application closes. But I would like to go back to menu screen and dispose there, since I do disposing of resources there (via asset manager). I have buttons for exiting in the game and if exiting is done that way, it's fine. The trouble is that the red cross can be pressed. So how could I handle disposing properly in that case?

On the android version, I catch the back key and handle leaving different parts of the game and the whole game in my own way. And there it works OK.

Another related question I have:

On desktop the application cannot get stopped and then disposed (on it's own, without user explicitly exiting it) like the android version can (the android life cycle), right? So is it a good idea, if I do a temporary save on pause() and restore game state from that on resume(), that I don't restore on desktop (since the restoring isn't a complete restore and I don't want restoring to happen if, on desktop, the window is just minimized (as I noticed, pause()/resume() gets called when minimizing/restoring window )).

Hope this wasn't too unclear :D. I've tried to google for answers but don't seem to find anything. Any help is much appreciated.

Upvotes: 5

Views: 4733

Answers (4)

Noam Preil
Noam Preil

Reputation: 11

As mentioned above, the Screen interface contains a dispose method. Additionally, the dispose method of Game can be overridden to dispose of the current screen automatically. However, there is a reason this is not the default. Let's say you have multiple Screens - Screen1and Screen2. Screen1 was active, then changed the screen to 2. The game is then exited, and the dispose method is called, which calls the current screen's dispose method - leaving screen 1 alone.

My preferred method is to have the game keep track of screens set by overriding the setScreen method and adding a Screen[] screens, a boolean[] scrDiss, and an index. When dispose is called on Game, it checks through all screens set, checks if previously disposed, and disposes if not. Additionally, the Screen dispose methods should call a method on the Game that finds it in the array, and marks it disposed. This way, screens can be disposed before the end of the Game, but when Game is disposed, all Screens will be as well.

Upvotes: 1

Sheraz Ahmad Khilji
Sheraz Ahmad Khilji

Reputation: 8358

You can call dispose() of your Screen by calling it explicitly from your Game Class dispose() like this

MyScreen Class:

public class MyScreen implements Screen {
    // Not going to write all other methods that need to be overridden

    @Override
    public void dispose() {
        // Clear you Screen Resources here
    }

}

MyGame Class:

public class MyGame extends Game {
    // Not going to write all other methods that need to be overridden

    @Override
    public void create() {
        setScreen(new MyScreen());

    }

    @Override
    public void dispose() {
        // Clear you Screen Explicitly
        getScreen().dispose();

    }
}

Hope this helps

Upvotes: 3

donfuxx
donfuxx

Reputation: 11323

I suggest using the libgdx life-cycle methods

To dispose you should use the dispose() method. You don't need to call dispose yourself! It will be called automatically when the application gets destroyed, see documentation:

dispose () Called when the application is destroyed. It is preceded by a call to pause().

So just implement the dispose method in your Screens:

@Override
public void dispose () { 
    //your code needs to get added here, like for example:
    stage.dispose();
    texture.dispose();
    //etc..
}

Update: Note that dispose() of AppliacationListener gets called automatically, not dispose() of Screen, see comment of Springrbua

Upvotes: 4

Chase
Chase

Reputation: 3183

Call dispose on all your screens when your application is disposed.

Upvotes: 0

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