I've written an item that requires an amount of redstone to be in the player's inventory, but I can't work out how to make it require and consume x redstone.

 

What I want is:

[*]Player uses item

[*]Item checks if Player has 12 redstone or more in their inventory

[*]If they do, remove 12 redstone form their inventory

 

This is the code I'm using at the moment as a placeholder:

if (entityplayer.capabilities.isCreativeMode || entityplayer.inventory.hasItem(Item.redstone.itemID))
{
entityplayer.inventory.consumeInventoryItem(Item.redstone.itemID);
}

for loop to call the line 12 times?

I thought of that, but it would be really convoluted to call it 12 times and replace the redstone for each of the redstone dusts used; i was wondering if there's a more elegant way, before using that method?

Looking at EntityPlayer and PlayerInventory might give you some better ways.

But from a quick look at them I didn't see any method to remove a stack of X size from the inventory, which is weird as I would think that quite useful.

 

You could check the slots of the players inventory and if you 12 or more you can remove 12 of them by setting the item stack in the given slot?

When I did something like this for Extendable Ladders, I looped it.  As each placement was dependent on where it was placed and when it should stop placement.

Get stack in slot and decrease stack size.

You'll need loops in the worst case that the player has redstone all over its inventory.