Call a Fragment method from an Adapter

Solution 1:

Edit : Here is what I would use now. Older, "easier" solutions are available below.

MyFragment extends Fragment implements CustomAdapter.EventListener {

    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

        CustomAdapter adapter = new CustomAdapter(..., this);

    }

    void onEvent(int data) {
        doSomething(data);
    }

}

CustomAdapter extends BaseAdapter {

    EventListener listener; 

    public interface EventListener {
        void onEvent(int data);   
    }

    public CustomAdapter(..., EventListener listener) {
        this.listener = listener; 
    }

    ...

}

Now from any place in the adapter we can call listener.onEvent(data); to trigger the method in the fragment.

Moreover, instead of providing a listener through the constructor, we can add another method in the adapter such as registerListener(EventListener eventListener) and then maintain a list of listeners if needed.

Old Answer:

Solution 1 : Make the adapter an inner class of your fragment, so that you can call the method directly.

Solution 2 : Update your adapter constructor to accept the Fragment as a parameter.

Something like :

customAdapter = new CustomAdapter(myContext, android.R.layout.simple_list_item_1, getList, HomeFragment.this);

and update the constructor of the Adapter :

public CustomAdapter(Context context, int id, HomeFragment fragment) {
    this.fragment = fragment;
}

then you call methods using the fragment variable.

fragment.doSomething();

Solution 2:

I know it's late to answer but There are 2 ways more to do it:

1. You can also send broadcast from adapter and register it in fragment.

2. Use interface. Refer this SO question for details.