Updating item data from the ViewHolder class

Question

I am confused with ViewHolder. I just started converting all my ArrayAdapters and ListView to RecyclerView with Adapters and Holders. When converting, I get stuck in the way I used to set click listeners.

Basically, in the past, I would get the position, retrieve the item at position pos and then perform the layouting of the item depending on the data in my ArrayList's item.

@SuppressLint("ClickableViewAccessibility")
@Override
public View getView(int position, View view, ViewGroup parent) {
    LayoutInflater inflater = context.getLayoutInflater();
    View rowView = inflater.inflate(R.layout.list_items, null, true);


    Data currentData = (Data) getItem(position);

    myTextView.setText(currentData.title);
    myTextView.setOnClickListener(v->actionThatDependsOnPositionAndOrData());


 }

So in my ClickListener, I would have something that depends on the position, and some kind of callback that updates the ArrayList or stuff like this.

Now, it seems like I have no way to retrieve the position anymore.

@Override
public <T extends DownloadableData> void bindData(T data) {
    super.bindData(data);

    myTextView.setOnClickListener(v->actionThat????)
}

So how do I specify the position?

Because right now, the only way that I found in my AsyncTask in the clickListener is to call the Fragment that has the RecyclerView and do this

 public void myCallback(Data data, String newTitle){

     int index=allData.indexOf(data);
     performModificationOfData(data); //like data.title=newTitle;
     allData.set(index, data);
     adapter.notifyDataSetChanged(); //not even sure this is needed..
    }

Isn't there a smarter way to do it?

Answer 1

Please check following adapter, it will help you to understand how to set click listener on a view inside the adapter. Inside the onBindViewHolder method setOnItemClick listener. Then in the activity set that callback and you will get override method of that callback with data and position. Then do whatever you want on item click.

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;  
import android.view.View;  
import android.view.ViewGroup;  
import android.widget.ImageView;  
import android.widget.RelativeLayout;  
import android.widget.TextView;  
import android.widget.Toast;  


public class MyListAdapter extends RecyclerView.Adapter<MyListAdapter.ViewHolder>{  
    private MyListData[] listdata;  
    private ItemclickCallback callback;

   // RecyclerView recyclerView;  
    public MyListAdapter(MyListData[] listdata) {  
        this.listdata = listdata;  
    }

    public void setCallback(ItemclickCallback callback) {
        this.callback = callback;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {  
        LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());  
        View listItem= layoutInflater.inflate(R.layout.list_item, parent, false);  
        ViewHolder viewHolder = new ViewHolder(listItem);  
        return viewHolder;  
    }  

    @Override  
    public void onBindViewHolder(ViewHolder holder, int position) {  
        final MyListData myListData = listdata[position];  
        holder.myTextView.setText(listdata[position].getDescription());  
        holder.imageView.setImageResource(listdata[position].getImgId());  
        holder.myTextView.setOnClickListener(new View.OnClickListener() {  
            @Override  
            public void onClick(View view) {  
                Toast.makeText(view.getContext(),"click on item: "+myListData.getDescription(),Toast.LENGTH_LONG).show(); 
                onTextViewClick(myListData,position); 
            }  
        });  
    }  


    interface ItemclickCallback{
        void onTextViewClick(MyListData myListData,int position);
    }

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

    public static class ViewHolder extends RecyclerView.ViewHolder {  
        public ImageView imageView;  
        public TextView myTextView;  
        public ViewHolder(View itemView) {  
            super(itemView);  
            this.imageView = (ImageView) itemView.findViewById(R.id.imageView);  
            this.myTextView = (TextView) itemView.findViewById(R.id.myTextView);  
        }  
    }  
}