Slick & NiftyGUI. Nifty initialize exception

Question

I found my self into trouble when trying to run a Slick game with a Nifty Game State. This is the code:

@Override
protected void initGameAndGUI(GameContainer container, StateBasedGame game)
        throws SlickException {
    initNifty(container, game);     
}

If i run this i get: java.lang.IllegalStateException: The NiftyGUI was already initialized. Its illegal to do so twice.

If i delete the call to initNifty() i get another exception:java.lang.IllegalStateException: NiftyGUI was not initialized.

Answer 1

This evening I switched switched from TWL to Nifty to give it a try. I experienced some of the same issues as you. I did get it working though. The documentation isn't great and there's no complete example at the end, so it's hard to know exactly what you're supposed to do at a glance. Below I've included the function I implemented to properly set up Nifty.

As the documentation states(see manual), your main game class is supposed to extend NiftyOverlayGame, or one of the other classes it lists, as I answered in your other question.

One of the functions you need to override is initGameAndGUI and I believe this is where your issue originates from. This is how I did it properly:

protected void initGameAndGUI(GameContainer gc) throws SlickException {
    renderDevice = new SlickRenderDevice(gc);
    soundDevice = new SlickSoundDevice();
    inputSystem = new SlickSlickInputSystem(new PlainSlickInputSystem());
    timeProvider = new LWJGLTimeProvider();
    gui = new Nifty(renderDevice, soundDevice, inputSystem, timeProvider);
    initNifty(gc);
}

Where these objects were defined inside my main class as (I'll include the imports as well for reference):

import de.lessvoid.nifty.Nifty;
import de.lessvoid.nifty.slick2d.NiftyOverlayGame;
import de.lessvoid.nifty.slick2d.input.PlainSlickInputSystem;
import de.lessvoid.nifty.slick2d.input.SlickSlickInputSystem;
import de.lessvoid.nifty.slick2d.render.SlickRenderDevice;
import de.lessvoid.nifty.slick2d.sound.SlickSoundDevice;
import de.lessvoid.nifty.slick2d.time.LWJGLTimeProvider;
import de.lessvoid.nifty.spi.input.InputSystem;
import de.lessvoid.nifty.spi.sound.SoundDevice;

...

public final class MainGame extends NiftyOverlayGame  {
    Nifty gui;
    SoundDevice soundDevice;
    SlickRenderDevice renderDevice;
    InputSystem inputSystem;
    TimeProvider timeProvider;
    ...

Hopefully setting up your code similar to this should help you get on the right track (if you haven't figured this out already).

Answer 2

I'm using nifty 1.3.2 and I had the same issue. Whenever I use a state based implementation, I got the error described above. This seems definitely to be a bug in nifty. Their examples does not implement slicks state-based implementations...

I could make it running by manipulating the source and build my own jar file of nifty-slick-renderer-1.3.2

I know the following change does not solve the issue, but will make your code run. Change

if (guiPrepared) {
  throw new IllegalStateException("The NiftyGUI was already initialized. Its illegal to do so twice.");
}

to

if (guiPrepared) {
  return;
}

and rebuild the jar file (and name it custom or so). This change will just ignore the second run of trying to build nifty.