Is that a right way of using interface callback?

Question

I read this and this and found out that in class B I need to save a reference to class A and when something happens in class B we exec

Answer 1

In my opinion, it's not a good programming manner. Generally you even don't need interfaces to implement such design, you can override every method of a class when you're instantiating it. Actually you're not instantiating that class, you're instead instantiating an anonymous class which subclasses that class.

Let's head back to the problem, interfaces are meant to be used as literally their name suggests. They should be used as an interface between two components. From software engineering point of view, suppose you're in a team that develops a large-scale software system, in this case in design phases you an your teammates should agree on a standard and globally-acceptable interface by which two components are going to interact and additionally suppose implementation of one of this two is up to you and the other one is going to be implemented by your teammates, so for interoperability your codes must comply with that interface and so is for your teammates.

In your case, you're actually merging that standard interface into your own component, so your teammates may be unhappy with this.

TL;DR:

Your approach is not good.