recycler view header adapter

gistfile1.txt

import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;

/**
 * Created by khaled bakhtiari on 10/26/2014.
 * <a href="http://about.me/kh.bakhtiari">
 */
 public class HeaderAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    private static final int TYPE_HEADER = 0;
    private static final int TYPE_ITEM = 1;
    String[] data;

    public HeaderAdapter(String[] data) {
        this.data = data;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        if (viewType == TYPE_ITEM) {
            //inflate your layout and pass it to view holder
            return new VHItem(null);
        } else if (viewType == TYPE_HEADER) {
            //inflate your layout and pass it to view holder
            return new VHHeader(null);
        }

        throw new RuntimeException("there is no type that matches the type " + viewType + " + make sure your using types correctly");
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        if (holder instanceof VHItem) {
            String dataItem = getItem(position);
            //cast holder to VHItem and set data
        } else if (holder instanceof VHHeader) {
            //cast holder to VHHeader and set data for header.
        }
    }

    @Override
    public int getItemCount() {
        return data.length + 1;
    }

    @Override
    public int getItemViewType(int position) {
        if (isPositionHeader(position))
            return TYPE_HEADER;

        return TYPE_ITEM;
    }

    private boolean isPositionHeader(int position) {
        return position == 0;
    }

    private String getItem(int position) {
        return data[position - 1];
    }

    class VHItem extends RecyclerView.ViewHolder {
        TextView title;

        public VHItem(View itemView) {
            super(itemView);
        }
    }

    class VHHeader extends RecyclerView.ViewHolder {
        Button button;

        public VHHeader(View itemView) {
            super(itemView);
        }
    }
}

I would just add that if you don't want the header/footer to be displayed if the data set is empty to change:

    @Override
    public int getItemCount() {
       if (data.isEmpty() {
          return data.length;
       } else {
           return data.length + 1;
        }
    }

I am trying to implement with a footer only. The part i'm confused about is how do I tell if the position is the footer? It makes sense with a header because its at position 0, but the position of my footer will keep changing. Any thoughts? Thanks!

position for footer is always getItemCount() -1 (meaning always the las item)

Hi, hister. I successfully used this to create a header (which is basically a refresh progressbar). The issue is I want to hide this header (GONE treatment) but can't seem to make this work. Any suggestion?

@jpshelley, I think you ment the other way around:

    @Override
    public int getItemCount() {
       if (data.isEmpty()) {
          return data.length + 1;
       } else {
           return data.length;
        }
    }

This will show the header if the data is empty.

What to do if i dnt want header for one Activity and want header in another activity with same adapter

@rafiqlightwala i've had the same problem what i did to solve the issue was to set visibility to gone on every child of the footer (i had a refresh progressbar as well, with a textview and a button)

@mmanishh you could easily send a flag to show the footer or not
or you could have a inheritance of the adapter that doesn't show the footer of course you'd need to tweak the code a bit

The first item for Recyclerview is not displayed . Can u tell why ? and the solution too

How can we implement this with multiple Headers?

Is there a way we can add Accordion behavior to this ?

I have been followed above example but In my case, It only shows the header and rest of items showing blank. I have checked that logs showing the data but It's not visible in Recyclerview rows. Can anyone tell me why it's happening?