[1.16.3] [Solved] PlayerContainerEvent.Open not fired for Player's Inventory

[JimiIT92 20]

I'm trying to attach a listener to the Player Inventory, to do something when the Player change an ItemStack inside a slot.
To do this I'm adding the listeners to the container that is opened using the PlayerContainerEvent.Open event.
This works for basically any container, except the one I want, which is the Player Container (more specifically the Hotbar and Player Inventory).

 

This is what I've done
 

@SubscribeEvent
public static void onInventoryOpen(final PlayerContainerEvent.Open event) {
  Container container = event.getContainer();
  if(!event.isCanceled() && (container instanceof PlayerContainer ||
      	container instanceof CreativeScreen.CreativeContainer)) {
            container.addListener(new BundleContainerListener());
  }
}

So I'm checking if the Container that has been opened is a PlayerContainer or a CreativeContainer (because PlayerContainer is just the Survival Inventory and I want this listener to work in creative mode too). If it is I then add my listener to the Container, from which I'm able to do whatever I want

public class BundleContainerListener implements IContainerListener {

    @Override
    public void sendAllContents(Container containerToSend, NonNullList<ItemStack> itemsList) {

    }

    @Override
    public void sendSlotContents(Container containerToSend, int slotInd, ItemStack stack) {
        System.out.println("CONTAINER: " + containerToSend + " - SLOT: " + slotInd + " - STACK: " + stack);
    }

    @Override
    public void sendWindowProperty(Container containerIn, int varToUpdate, int newValue) {

    }
}

If I open a Chest and set a breakpoint at the beggining of the onInventoryOpen event, the breakpoint gets hit. However if I open the Player inventory it doesn't.
The interesting part is that the PlayerContainerEvent.Close event gets called. So if I change the onInventoryOpen function to this

@SubscribeEvent
public static void onInventoryOpen(final PlayerContainerEvent.Close event) {
  Container container = event.getContainer();
  if(!event.isCanceled() && (container instanceof PlayerContainer ||
      	container instanceof CreativeScreen.CreativeContainer)) {
            container.addListener(new BundleContainerListener());
  }
}

and open the Player Inventory, the event gets called and the listener added as well. So when I reopen the Player Inventory, the code from the Listener gets called. But this requires the Player to open and close the Inventory the first time, which of course is something I want to avoid. 
Any idea on why the Open event doesn't gets called for Player Inventory, but the Close one does?
Also, since I don't need the other two methods from the listener, is it fine to leave them as empty or should I call something in the container class? I didn't see any issue, but I want to know just to make things right
 

Edited October 7, 2020 by JimiIT92
solved

[diesieben07 7774]

The server has no idea whether or not you are looking at your inventory. The PlayerContainer is always open, unless you are looking at a different container (e.g. a chest).

If you want to modify the player container somehow, do it in PlayerLoggedInEvent.

The creative GUI is entirely client side, the client simply sends a packet saying "please spawn this stack in this slot". The server still just has the PlayerContainer (the normal inventory) open.

[JimiIT92 20]

Ok, but how can I do that? Because I can't just do this
 

@SubscribeEvent
public static void onPlayerLoggedIn(final PlayerEvent.PlayerLoggedInEvent event) {
  event.getPlayer().container = new CustomContainer();
}

since the container property is final.

I could also just add the listener here, using the addListener, but I noticed that the code from my listener is executed after the code from the existing listeners. What I'm trying to achieve is to intercept when the player changes an ItemStack into a slot and cancel the event or do some stuff accordingly. But when the code from my listener runs, the slot content has already been changed, so I can't determine what was in the slot and what I'm trying to put inside. Is there a way to set a priority for listeners, so my listener will run before any other?

 

EDIT: Figured out I have to change the value for openContainer. By doing this I can now set a custom implementation of the PlayerContainer. Thank you for the help, but I'm still curious about the listeners priority, and if there is such a way to do it (to avoid using a custom implementation)

Edited October 7, 2020 by JimiIT92
solved

[diesieben07 7774]

Do you really need a custom implementation? this will be very much incompatible with other mods.

 

Reading helps.

The listeners are just a list, you can prepend to it as well, using some reflection hackery.

[JimiIT92 20]

5 hours ago, diesieben07 said:

The listeners are just a list, you can prepend to it as well, using some reflection hackery.

Yes, I know they are just a list. What I want to avoid is using reflection to prepend my listener 😅

[diesieben07 7774]

10 hours ago, JimiIT92 said:

What I want to avoid is using reflection to prepend my listener 😅

It's better than just bulldozing over the whole container.

[JimiIT92 20]

Well, in the end I figured out I didn't even need a listener. All I need was to catch the ClickEvent 😅