How to Set BaseAdapter for RecyclerView?

Question

Whenever I need to implement a custom ListView or GridView . I always use a BaseAdapter class like this:

public class CustomFlowerGridViewAdapter extends BaseAdapter {

private HashMap<String, String> mFlowerFeed = new HashMap<>();

private Context mContext;
static LayoutInflater mFlowerInflater = null;

CustomFlowerGridViewAdapter(Context context, ArrayList<HashMap<String, String>> data) {

    super();
    this.mContext = context;
    MainActivity.flowerArrayFeedList = data;
    mFlowerInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

}

@Override
public int getCount() {
    return MainActivity.flowerArrayFeedList.size();
}

@Override
public Object getItem(int i) {
    return MainActivity.flowerArrayFeedList.size();
}

@Override
public long getItemId(int i) {
    return i;
}

@Override
public View getView(int i, View view, ViewGroup viewGroup) {

    final ViewHolder holder;

    if(view == null){

        view = mFlowerInflater.inflate(R.layout.flower_grid_row, viewGroup, false);

        holder = new ViewHolder();

        holder.name = (TextView) view.findViewById(R.id.mainGridName);

        view.setTag(holder);
        mFlowerFeed = MainActivity.flowerArrayFeedList.get(i);
        mFlowerImage = MainActivity.flowerArrayImageList.get(i);

    }
    else{
        holder = (ViewHolder) view.getTag();
        mFlowerFeed = MainActivity.flowerArrayFeedList.get(i);
        mFlowerImage = MainActivity.flowerArrayImageList.get(i);

    }

    holder.name.setText(mFlowerFeed.get("name"));

    return view;
}

private class ViewHolder {

    TextView name

 }
}

However, now I'm trying to implement a Horizontal ListView. After doing some research, I found that the "correct" way to implement a Horizontal ListView is to use a RecyclerView. This is what I have in my MainActivity

CustomFlowerGridViewAdapter customFlowerGridViewAdapter = new CustomFlowerGridViewAdapter(MainActivity.this, flowerArrayFeedList);
    flowersGrid.setAdapter(customFlowerGridViewAdapter);

The problem is when I try set the adapter.

How do I set a BaseAdapter to a RecyclerView?

Answer 1

You don't. RecylerViews accept another kind of adapter, different from the one in ListView. A simple example of adapter with a list of strings:

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
    private String[] mDataset;

    public static class ViewHolder extends RecyclerView.ViewHolder {
        public TextView mTextView;
        public ViewHolder(TextView v) {
            super(v);
            mTextView = v;
        }
    }

   public MyAdapter(String[] myDataset) {
        mDataset = myDataset;
    }

    @Override
    public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                                   int viewType) {
        TextView v = (TextView) LayoutInflater.from(parent.getContext())
                .inflate(R.layout.my_text_view, parent, false);
        ...
        ViewHolder vh = new ViewHolder(v);
        return vh;
    }


    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.mTextView.setText(mDataset[position]);

    }


    @Override
    public int getItemCount() {
        return mDataset.length;
    }
}

This one can be found in the docs. So you need to implement a ViewHolder class that and your adapter will use. Your adapter needs to extend RecyclerView.Adapter.

To set the list to be horizontal you need to set a LinearLayourManager in your recycler view with the Horizontal property set.

LinearLayoutManager layoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
recyclerView.setLayoutManager(layoutManager);
MyAdapter adapter = new MyAdapter(dataset);
recyclerView.setAdapter(adapter);