Since like forever people been doing this kind of thing where "you are not allowed to use this item".

 

Now - everytime it was done (that I know of) the way was to use PlayerTickEvent or Item#onUpdate() and check if item is current item and if so - move it to other slot, because "you can't use it".

 

Question arises - is there other more "right now" way when executing code (changing the current slot).

 

Whenever, whoever makes some IInventory - it's clear and you can use isItemValid or some other stuff, you can't really do that in vanilla. Is there a hook somewhere?

 

I can deal with ticks, but just asking for yes or no (or something else?).

 

EDIT

By "right now" I ment that you don't use tick-checks, which would avoid e.g constatly checking NBT or other stuff.

Maybe you can handle the clicking on the hotbar and related input / keybind ect. that are used when player wants to put something in the hand?

Maybe you can handle the clicking on the hotbar and related input / keybind ect. that are used when player wants to put something in the hand?

You certainly can, sort of - I do this while one of the sword skills is active to prevent changing the current item.

 

MouseEvent has a field called 'dwheel' which indicates whether the mouse wheel is in use (+/- for up/down scrolling, zero for no input). You will also need to check the number keys using KeyInputEvent for direct changes.

 

I haven't tried it within a GUI screen, but as long as both of those events are fired, you could probably rig up something. Checking if the open GUI is a GuiContainer, for example, and then casting would probably allow you to figure out what the current slot clicked / item is.

 

Honestly, though, and contrary to what I usually try to promote, I think the ticking solutions are the better solution here. There are just so many ways that an item can get into a player's hotbar slot (picking up, shift-click, manually via direct inventory manipulation in code, etc.), that you can't possibly cover them all unless you actually check the slots involved and what they currently contain.