Getting position of View in onCreateViewHolder

Question

I am using a RecyclerView with a single row layout with an ImageView and a TextView.

I want to implement a OnClickListener for the View and not for seperate ViewHolder objects. How can i get the position of the view in the Adapter?

Right now i'm deleting comments on click, but i cannot select the clicked View. I added a TODO in the appropriate line.

public class CommentAdapter extends RecyclerView.Adapter<CommentAdapter.ViewHolder> {      /** List of Comment objects */     private List<Comment> mCommentList;      /** Database with Comment objects */     private CommentsDataSource mDataSource;      /**      * Construcutor for CommentAdapter      *      * @param commentList   List of Comment objects      * @param dataSource    Database with Comment objects      */     public CommentAdapter(List<Comment> commentList, CommentsDataSource dataSource) {         this.mCommentList = commentList;         this.mDataSource = dataSource;     }      /**      * Add Comment objects to RecyclerView      *      * @param position  The position where the Comment object is added      * @param comment   Comment Object      */     public void add(int position, Comment comment) {         mCommentList.add(position, comment);         notifyItemInserted(position);     }      /**      * Remove Comment objects from RecyclerView      *      * @param comment Comment Object      */     public void remove(Comment comment) {         int position = mCommentList.indexOf(comment);         // Avoid double tap remove         if (position != -1) {             mCommentList.remove(position);             mDataSource.deleteComment(comment);             notifyItemRemoved(position);         }     }      @Override     public ViewHolder onCreateViewHolder(final ViewGroup parent, int viewType) {         final View view = LayoutInflater.from(parent.getContext())                 .inflate(R.layout.single_line_row, parent, false);         view.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                 // TODO get position                 remove(mCommentList.get(getItemCount() - 1));             }         });         return new ViewHolder(view);     }      @Override     public void onBindViewHolder(ViewHolder holder, int position) {         final Comment comment = mCommentList.get(position);         holder.comment.setText(comment.getComment());     }      @Override     public int getItemCount() {         return mCommentList.size();     }      public static class ViewHolder extends RecyclerView.ViewHolder {          /** ImageView icon */         public ImageView icon;          /** TextView comment */         public TextView comment;          /**          * Constructor for ViewHolder          *          * @param itemView Layout for each row of RecyclerView          */         public ViewHolder(final View itemView) {             super(itemView);             icon = (ImageView) itemView.findViewById(R.id.icon);             comment = (TextView) itemView.findViewById(R.id.comment);         }     } } 

Answer 1

You cannot use the position parameter of onBindViewHolder in a callback. If a new item is added above, RecyclerView will not rebind your item so the position is obsolete. Instead, RecyclerView provides a getAdapterPosition method on the ViewHolder.

@Override public ViewHolder onCreateViewHolder(final ViewGroup parent, int viewType) {     final View view = LayoutInflater.from(parent.getContext())             .inflate(R.layout.single_line_row, parent, false);     final ViewHolder holder = new ViewHolder(view);     view.setOnClickListener(new View.OnClickListener() {         @Override         public void onClick(View v) {             final int position = holder.getAdapterPosition();             if (position != RecyclerView.NO_POSITION) {                 remove(mCommentList.get(position));             }         }     });     return holder; } 

I've added position != RecyclerView.NO_POSITION check because when item is removed, RecyclerView will fade out the View so it may still be clicked by the user but its adapter position will return NO_POSITION.

Answer 2

you can create a method to update position in your class.

in my case I need to attach watcher and get the position to update arraylist. here is the example:

class DodolWatcher bla bla {     private var position: Int = 0     fun updatePosition(pos:Int)     {       position = pos     }      override fun onTextChanged(charSequence: CharSequence, i: Int, i2: Int, i3: Int) {     Log.d("test", position.toString())     }  } 

and in your onCreateViewHolder you can attach watcher to edittext

 override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RVPaymentMethodAdapter.ViewHolder {      ....      bla bla      ....      theWatcher = DodolWatcher() <-- this is the trick      amount.addTextChangedListener(theWatcher)  } 

and you will able to update position in your bindViewHolder like this:

override fun onBindViewHolder(viewHolder: RVPaymentMethodAdapter.ViewHolder, position: Int) {      theWatcher.updatePosition(viewHolder.adapterPosition)  <-- this is the trick  }