I am trying to make a machine that has an upgrade slot that has an item limit of 1. I've tried overriding a lot of functions and even making a custom SlotItemHandler class, but nothing worked.

How would one go about making this? 

i have not test it but 
you must extend the slot class overriding the max stack size to 1 

	public int getMaxStackSize() {
return this.container.getMaxStackSize();
}
	

 

then in the menu class use your custome slot class to declare the slot 

 

this.addSlot(new SlotItemHandler(handler00, 6, 62, 35));//slot zero

this.addSlot(new ArmourSlotItemHandler(handler00, null,5, 80, 8));//head

 

I tried that, and the problem is I can still insert a full stack by hand.

Got it to work, for anyone that has this same question, here's the code:
- In the EntityMenu

this.blockEntity.getCapability(ForgeCapabilities.ITEM_HANDLER).ifPresent(iItemHandler -> {
            this.addSlot(new SlotItemHandler(iItemHandler, 0, 12, 15) {
                @Override
                public int getMaxStackSize() {
                    return 1;
                }

                @Override
                public int getMaxStackSize(@NotNull ItemStack stack) {
                    return 1;
                }

                @Override
                public void set(@NotNull ItemStack stack) {
                    ItemStack copiedItemStack = stack.copyWithCount(1);
                    super.set(copiedItemStack);
                    return;
                }
            });
            this.addSlot(new SlotItemHandler(iItemHandler, 1, 86, 15));
            this.addSlot(new SlotItemHandler(iItemHandler, 2, 86, 60));
        });

 

Adding an anonymous class to the slot you want to have this, and in the class you override the three methods.

Now if you want other number of items, replace the 1's in the methods with the number you want.

PS. The return line at the end of set() is not needed.

Edited June 10, 20241 yr by IlluminatiJoe