Easy Implementation of RecyclerView custom onItemClickListener

README.md

#The Problem In the way of replacing ListViews with RecyclerView I hit this obstacle where there is no onItemClickListener in RecyclerView ??? And when googled, I found almost all the posts saying we have to implement this using the GestureDetector. And some of them had used interfaces which is what I too thought of using in the first place. But even they were so much confusing and complex to understand.

#Solution

Prerequisites

1. Interfaces (Donot worry if you never used one. But they are very simple concept) - CustomItemClickListener.java
2. ViewHolder Adapter - ItemsListAdapter.java
3. ViewHolder Item Class - ItemsListSingleItem.java
4. The RecyclerView Itself - ItemsList (See Setting up the RecyclerView)

Solving the problem

Consider for example you have a list of thumbnails and a title to be listed. I would do the following to keep stuff simple and working. :)

Checkout the sample project here

activity_list.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/items_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</LinearLayout>

CustomItemClickListener.java

public interface CustomItemClickListener {
    public void onItemClick(View v, int position);
}

ItemsListAdapter.java

public class ItemsListAdapter extends RecyclerView.Adapter<ItemsListAdapter.ViewHolder> {
    ArrayList<ItemListSingleItem> data;

    Context mContext;
    CustomItemClickListener listener;

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View mView = LayoutInflater.from(parent.getContext()).inflate(R.layout.items_list_single_item, parent, false);
        final ViewHolder mViewHolder = new ViewHolder(mView);
        mView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                listener.onItemClick(v, mViewHolder.getPosition());
            }
        });
        return mViewHolder;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.itemTitle.setText(Html.fromHtml(data.get(position).getTitle()));
        if (!TextUtils.isEmpty(data.get(position).getThumbnailURL())) {
          // I Love picasso library :) http://square.github.io/picasso/
            Picasso.with(mContext).load(data.get(position).getThumbnailURL()).error(R.drawable.ic_no_image).
                    placeholder(R.drawable.ic_no_image).
                    transform(new RoundedCornersTransformation(5, 0)).
                    into(holder.thumbnailImage);
        } else {
            holder.thumbnailImage.setImageResource(R.drawable.ic_no_image);
        }
    }


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

    public ItemsListAdapter(Context mContext, ArrayList<ItemsListSingleItem> data, CustomItemClickListener listener) {
        this.data = data;
        this.mContext = mContext;
        this.listener = listener;
    }

    public static class ViewHolder extends RecyclerView.ViewHolder {
        public TextView itemTitle;
        public ImageView thumbnailImage;

        ViewHolder(View v) {
            super(v);
            itemTitle = (TextView) v
                    .findViewById(R.id.post_title);
            thumbnailImage = (ImageView) v.findViewById(R.id.post_thumb_image);
        }
    }
}

ItemsListSingleItem.java

public class ItemsListSingleItem {
    private String title,thumbnailURL;
    /**
     * Just for the sake of internal reference so that we can identify the item.
     */
    long id;

    /**
     *
     * @param id
     * @param title
     * @param thumbnailURL
     */
    public ItemsListSingleItem(long id, String title, String thumbnailURL) {
        this.id = id;
        this.title = title;
        this.thumbnailURL = thumbnailURL;
    }

    public String getTitle() {
        return title;
    }

    public long getID() {
        return id;
    }

    public String getThumbnailURL() {
        return thumbnailURL;
    }
}

ListActivity.java

public class HomeActivity extends AppCompatActivity{
    RecyclerView itemsList;
    ItemsListAdapter adapter;
    ArrayList<ItemsListSingleItem> data = new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_list);
      
      itemsList = (RecyclerView) getView().findViewById(R.id.items_list);
      itemsList.setHasFixedSize(true);
      mLinearLayoutManager = new LinearLayoutManager(this);
      itemsList.setLayoutManager(mLinearLayoutManager);

      //let us add some items into the list
      data.add(
        new ItemsListSingleItem(
        1,
        "First Item",
        "www.someUrlToMyThumbnailImage1"
      ));
                   
      data.add(
        new ItemsListSingleItem(
        2,
        "Second Item",
        "www.someUrlToMyThumbnailImage2"
      ));
      
      adapter = new ItemsListAdapter(getActivity(), data, new CustomItemClickListener() {
        @Override
        public void onItemClick(View v, int position) {
            Log.d(TAG, "clicked position:" + position);
            long postId = data.get(position).getID();
            // do what ever you want to do with it
        }
      });
      itemsList.setAdapter(adapter);
    }
}

Thanks! This is so simple and cool.

what if in fragment??

Thank you very much for this solution!

Thank you very much for this solution!

Thank you very much for this solution!

Thank you very much for this solution!

Thank you very much for this solution!

Thanks man. I also made another interface called CustomItemHoldListener the same way you did. It's ridiculous that you even need to this, ListView was so much simpler! Oh well.

mViewHolder.getPosition() is deprecated.
ItemListAdapter.java:14:
listener.onItemClick(v, mViewHolder.getPosition());
to
listener.onItemClick(v, mViewHolder.getAdapterPosition());

Thanks man

I am getting error
Class 'Anonymous class derived from CustomItemClickListener' must either be declared abstract or implement abstract method 'onItemClick(HomeOptions, int)' in 'CustomItemClickListener'

Muchas Gracias 👍

This solution didn't work for me - every time my ClickListener returned index "-1".
The solution was change the place of implementing internal onClick method (in ItemViewHolder internal class, not in Adapter), like:
`public class MovieViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener, View.OnLongClickListener {

    public TextView title;
    public TextView year;
    public TextView genre;

    public MovieViewHolder(View view) {
        super(view);
        title = (TextView) view.findViewById(R.id.list_row_title);
        genre = (TextView) view.findViewById(R.id.list_row_genre);
        year = (TextView) view.findViewById(R.id.list_row_year);
        view.setOnClickListener(this);
        view.setOnLongClickListener(this);
    }

    @Override
    public void onClick(View v) {
        listener.onItemClick(v, this.getAdapterPosition());

// Log.d("ItemID", String.valueOf(this.getItemId()));
// Log.d("ItemLayoutPosition", String.valueOf(this.getLayoutPosition()));
// Log.d("ItemAdapterPosition", String.valueOf(this.getAdapterPosition()));
}

    @Override
    public boolean onLongClick(View v) {
        listener.onItemLongClick(v, this.getAdapterPosition());
        return true;
    }
}`

Your solution is perfect for Recyclerview click. But can you please let me know how can we handle individual item clicks ( 2 buttons inside the RecyclerView ) like the below
adapter = new ItemsListAdapter(getActivity(), data, new CustomItemClickListener() {
@OverRide
public void onItemClick(View v, int position) {
Log.d(TAG, "clicked position:" + position);
long postId = data.get(position).getID();
// which button clicked and separate action for each button
}
});

Thank you, your code help me so much

Its Good, But i Want to Pass Array Adpter to Recyclerview Using Interface, So How Can I do?

i have a problem whit RoundedCornerTransformation()...what is this....onBindViewHolder() methods....

Excellent, this solution is easy and help me so much :) thank you

Those Looking to add different button to different activities

    adapter = new CategoryAdapter(this, categoryList, new CustomItemClickListener() {
        @Override
        public void onItemClick(View v, int position) {
            long postId = categoryList.get(position).getID();
            if (postId == 1){
                Intent intent = new Intent(MainActivity.this, NewActivity.class);
                startActivity(intent);
            } else if (postId == 2){
                Intent intent1 = new Intent(MainActivity.this,  NewActivity1.class);
                startActivity(intent1);
            } else if (postId == 3){
                Intent intent2 = new Intent(MainActivity.this,  NewActivity2.class);
                startActivity(intent2);
            }
        }
    });
    recyclerView.setAdapter(adapter);

good solution, but I'm not sure about how the position gets where the CustomItemClickListener passed out as an argument in HomeActivity.(the code snippet below)
can anyone leave an explanation?

adapter = new ItemsListAdapter(getActivity(), data, new CustomItemClickListener() { @Override public void onItemClick(View v, int position) { Log.d(TAG, "clicked position:" + position); long postId = data.get(position).getID(); // do what ever you want to do with it } }); itemsList.setAdapter(adapter); }

thx help a lot
i am new in java so create iface and view on click it's kind of magical for me
but seems awesome!!!

Good idea!