Where to place onClickListener

Question

I have buttons in the rows of a RecyclerView within a Fragment within an Activity. Is it best to place the onClickListener and logic in the RecyclerView adapter or within the Fragments onActivityCreated method or the in the Activity?

Answer 1

I prefer MyFragment implements onClickListener

In the adapter's onBindViewHolder

button.setTag(position);
button.setOnClickListener(MyFragment.this);

In the onClick function

int position = view.getTag();

And then you can use the position variable to identify which button is clicked.

Answer 2

You put the listeners in the adapter, the logic somewhere else, for example the fragment.

So in your adapter, assuming Kotlin, for example:

...

var yourListener: (() -> Unit)? = null

...

override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
holder.itemView.setOnClickListener { yourListener?.let { it() } } 
}

And where you listener lives, and where the adapter is set:

var addCardClicked: (() -> Unit)? = null

...

adapter.yourListener = { yourListener() }

...
private fun yourListener() {
//does all kind of cool stuff
}

Answer 3

This works

public class ServiceListAdapter extends RecyclerView.Adapter<ServiceListAdapter.ViewHolder> {
private final Context mContext;
private List<ServiceListModel> categoryList;
private View.OnClickListener onClickListener;

public ServiceListAdapter(Context mContext, List<ServiceListModel> categoryList, View.OnClickListener onClickListener) {
this.categoryList = categoryList;
this.mContext = mContext;
this.onClickListener = onClickListener;
}

@Override
public ViewHolder onCreateViewHolder(final ViewGroup parent, final int viewType) {
final LayoutInflater inflater = LayoutInflater.from(parent.getContext());
final RowServiceListBinding binding = DataBindingUtil.inflate(inflater, R.layout.row_service_list, parent, false);
return new ViewHolder(binding.getRoot(), binding);
}

@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
holder.binding.rlService.setOnClickListener(onClickListener);
holder.binding.rlService.setTag(position);
}

@Override
public int getItemCount() {
return categoryList.size();
}

public class ViewHolder extends RecyclerView.ViewHolder {
private final RowServiceListBinding binding;

public ViewHolder(final View view, final RowServiceListBinding binding) {
    super(view);
    this.binding = binding;
}

@UiThread
public void bind(final ServiceListModel mAddressModel) {
    //this.binding.setAddress(mAddressModel);
}
}
}

Use in Activity/Fragment

ServiceListAdapter adapter = new ServiceListAdapter(context, serviceList, new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.rlService:
                int pos = (int) v.getTag();
                serviceList.remove(position);
                break;
        }
    }
});