I want to build a complex layout using recyclerview android. In the layout, I want to have a camera button to the top left fixed and a recyclerview wrapped around it with gallery images. I have checked flexbox layout manager for recyclerview but it doesn't seem to match my use-case.

I want the header to be non-repeating and not to scroll with other items vertically. Here's the layout for the header:

and in my activity, here's the XML:

Previously, I had the header inside the activity XML but had no way to wrap a recyclerview around it. So, I have decide to use an adapter like below:

public class TrendingAdapter extends RecyclerView.Adapter {

private static final String TAG = TrendingAdapter.class.getSimpleName();

private Context context;
private List itemList;

private static final int HEADER = 0;
private static final int ITEMS = 1;

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View v;
    switch (viewType){
        case HEADER:
           v = LayoutInflater.from(parent.getContext()).inflate(R.layout.trending_header, parent, false);
           return new TrendingHeaderViewHolder(v);
        case ITEMS:
            v = LayoutInflater.from(parent.getContext()).inflate(R.layout.trending_items_layout, parent, false);
            return new TrendingItemsViewHolder(v);
    }
    return null;
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
    Trending tr = itemList.get(position);
    if (holder instanceof TrendingHeaderViewHolder){
        ((TrendingHeaderViewHolder) holder).cameraShareIV.setOnClickListener( view -> {
            // TODO: 4/2/2018   select image from gallery
        });
    } else if (holder instanceof TrendingItemsViewHolder){
        // TODO: 4/2/2018 populate gallery items here with picasso  
    }
}

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

@Override
public int getItemViewType(int position) {
    return super.getItemViewType(position);
}
}

I'm confused how to make the header stick and also what to do for getItemViewType method.

Is this the right way to approach this? Can anyone help out? Thanks.