The button to interact will be the gamepad face button left. So I imagine that will feeding the call like part of the interface inside the third persob character
The interface goes into the actor you wish to interact with, not necessarily into the player (but it may help sometimes, too):
The premise it:
- the player pushes a button to interact
- if they have an item, they use it
- if they have no item, they search nearby for one
- what use means is up to the item itself to decide
- the interface functions:
- are implemented inside the interactive item:
- the player does the interacting:
You can combine the above with inheritance if necessary. In which case it’d be just he base class that needs the interface.