When an item is shift clicked from from a chest, it is organized into your inventory.

 

I.e. Shift clicking on 64 oak within a separate inventory will fill oak stacks in your inventory first, before adding new ones.

 

Is there a way to call that method, that transfers the stacks, from the event "PlayerOpenContainerEvent"?  Or will I have to write my own code?

 

Thanks!

The methods are reserved for containers and are fired when you actually shift-click stuff. It basically is written separately for each possible container to respect all slots of all inventories displayed in given container (one container can display many inventories - e.g: player's, chest's, crafting grid's, on and on...).

 

You can't just call those methods. They kinda work like this: "Oh, you shift clicked stack in some inventory at some index." -> "Lemme transfer that stack to the other inventory for you." -> *Iterates through other inventory* -> *Fills-up non-full stacks of same type* -> *Is something is left, places it in 1st possible slot - respecting design*.

 

Those methods are always written (for specific stack) to do transfering (from inv to inv), if you would want to sort all stacks so that you will get nicely stacked (sorted) ItemStacks in one inventory - that would look totally differently. So yeah - you need to write your method.

You could take a look at how InventoryTweaks does it.