Multiple interface implementations Android

Question

I have an Activity which implements two interfaces for call backs on certain actions. I want to send a context of my Activity to another Class which will access the object of the specified callback.

Here is my code :-

     public class OpenSchoolFragment extends Fragment implements IOpenSchoolCallBack, INetworkCallback
    {
// 1st case
       expandableListAdapter = new AdapterOpenSchool(getActivity(), this); // IOpenSchoolCallBack should provided

//2nd case
call.enqueue(new Callback<OpenSchool>()
        {
            @Override
            public void onResponse(Call<OpenSchool> call, Response<OpenSchool> response)
            {

                if (response.isSuccessful())
                {
                    OpenSchool userBatch = response.body();
                    if (userBatch != null)
                    {
                        RLProgressRoot.setVisibility(View.GONE);
                    }
                }
                else
                {
                    RLProgressRoot.setVisibility(View.GONE);
                    if (response.code() == getResources().getInteger(R.integer.integer_404))
                    {
                        DialogHelperUtil.showRetrySnackbar(RLContainer, getString(R.string.str_error_unauthorised),this); //INetworkCallBack should be provided

                    }
                    else
                    {
                        DialogHelperUtil.showMessageSnackbar(RLContainer, response.raw().message());
                    }
                }
            }

        }

So when I try to pass "this" in the second case, I get an error saying :-

Wrong 3rd argument type. Found: 'Callback<OpenSchool>', required: 'INetworkCallback'

How can I make sure the right callback is passed in "this" for the second case ie. INetworkCallback?

The error looks wrong. I feel there's something you're not showing us, like the second statement is called from an inner class or something. — Michael, Mar 04 '19 at 09:09
not sure, but try cast this to INetworkCallback, like `(INetworkCallback) this` — Linh, Mar 04 '19 at 09:10
@Michael Yes the second case is in an inner class. Updating my question — user3034944, Mar 04 '19 at 09:17
@user3034944 Then use `OpenSchoolFragment.this` instead of `this` — Michael, Mar 04 '19 at 09:18

score 1 · Accepted Answer · edited Mar 04 '19 at 09:19

1

The "this" refers to the current object in which you are in that precise point.

If your DialogHelperUtil.showRetrySnackbar() is called from Callback class, then this refers to Callback.

You can "exit" current inner-Class (Callback) and reach its outer-class by using OuterClass.this

edited Mar 04 '19 at 09:19

Michael

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answered Mar 04 '19 at 09:14

emandt

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Multiple interface implementations Android

1 Answers1