How to communicate between two child Fragments inside a Nested Fragment
android, fragment, interface
Solution
The cast thing is to ensure certain object is instance of class that implements given interface (in this case `OnHeadlineSelectedListener`). It's irrelevant at this point what type of object it is be it activity, fragment or anything else. As long as it implements the interface you need, it is all fine.
Problem
I can easily communicate between two `fragment`s of an activity by callback `interface`. Following that way, I have implemented an interface in `ParentFragment` to communicate. But in case of activity, I was using - ``` @Override public void onAttach(Activity activity) { super.onAttach(activity); try { mCallback = (OnHeadlineSelectedListener) activity; } catch (ClassCastException e) { throw new ClassCastException(activity.toString() + " must implement OnHeadlineSelectedListener"); } } ``` And in current case, I am using `mCallback = (OnHeadlineSelectedListener) getParentFragment();` instead of `mCallback = (OnHeadlineSelectedListener) activity;`. Everything is working well. Is this approach okay? Or should I do it into another thread instead `onAttach()`?