My question is how can one detect when an itemStack is being clicked on another specific item. for instance, if item1 = 1 and item2 = 2, (in the inventory, such the normal behavior is to have the ItemStacks switch places), if ItemStack 1 is being clicked on ItemStack 2, then do something. I have looked into various events and the potential of capabilities for the setItem method in ItemStack, yet i do not see a 'good' way of doing this function. How might I be able to implement such a function.

NOTE: Unless it is made in a way to guarantee that it will not cause any 'excessive' processing, if if it is the ONLY way, I do not care for some player event where the player inventory is checked every tick. Also, I do not care if it is a suggestion or the 'asnwer,' I mearly wish to know of what my potentials here are, what might work, what does, or just give up suggestions are all appreciated. 

 

EDIT: Or how might I find a way to detect changes in the ContainerPlayer class, for instance, is their an event for that?

EDIT: Due to issues in finding a potential answer to this, I shall specify further: I would like to add in a unique, custom way of 'crafting' recipes, where if item A is clicked on item B in slot, then both (ignoring specifics such as stack size) would be deleted from slot and replaced with item C. This would simply search from potential recipes to find matches. At this point, I am giving up on finding any reasonable solution.

Here's an option:

Override IContainerListener and add the listener to the container when it is created using Container.addListener. Perhaps the sendSlotContents method is the one you're looking for?

Looked into this a bit, but to specify, I am talking about for the player's inventory. How to detect if a specific ItemStack is clicked on another specific ItemStack in the player's inventory.

Player inventory uses IContainer as well so "when" a change happens in a container for a player's inventory, check to see what was going on.

 

I haven't looked much into container listeners but I know a few people have played with them. Mainly so far for capabilities.

Then my current question is of the most important, how should I do this. I say this in the respect of what is the best way. Is there a good hook I can use, or should I just put some if statements in the player tick event? Would prefer not to, but if that is the way, then so be it.

how can one detect when an itemStack is being clicked on another specific item.

or should I just put some if statements in the player tick event?

Well if you're looking for a item replacing another item via clicking. Tick Event won't cover that. You'd need something that would trigger with a "On Inventory" or "On Slot(container)" change that would know what the old and new ItemStack was for a Slot

 

This may not be 100% related, but it's close http://www.minecraftforge.net/forum/index.php?topic=42833.0

 

It's to do with Capabilities for ItemStacks, but I believe it can be easily applied to what you're trying to accomplish, yes it makes use of attaching a IContainerListener but that's so you can detect when something changes.

 

EDIT:

 

Well i guess you COULD use the tick event, but you'd have to store the old instance after each tick so you can compare and "See" the differences

Slot[6] was apple, next tick Slot[6] is now a cookie, do logic. But then of course you're scanning the Player inventory 2x each tick (old inv state you saved previous tick, and current inventory current tick) could take a bit of processing to run those two loops every tick

But then of course you're scanning the Player inventory 2x each tick (old inv state you saved previous tick, and current inventory current tick) could take a bit of processing to run those two loops every tick

 

That's actually an O(n) operation, not an O(2n).  You're still doing one loop, you're just comparing "old vs. new" and then either Doing Stuff or not, then saving new to old.  You don't need to loop twice.

 

But yes, not the most efficient way to do things.

Right, Thanks. Woke up not too long ago, some critical thinking is still trying to boot up.

Was making a basic blueprint for the capability, and the end result is that i am no where. I do not see a way to go anywhere with the capability.

Oh, Sorry. I don't think you need a Capability for what you're trying to do. Sorry if my suggestion lead you astray. I was hoping some info for using a IContainerListener would have helped. As your desired result is:

 

Holding Item A

Click on Item B (in inventory)

Magic happens??

 

Perhaps someone more versed will see this. Apologies for not being helpful

No, its not your fault, this is just a tricky subject, for the desired result. I would like to avoid using reflection, but the only way I seem to be able to do this is by either gaining access of some form to player inventory, or through itemStack, not the later, since itemstack is used everywhere and it is final. Just more searching in the forge and minecraft jars for me, is all