Save the state of the item selected in RecyclerView when the view is reused when scrolling

I created an adapter and ViewHolder for recyclerView. I bind an imageButton of an itemView element inside the Viewholder. And set onClickListener inside onBindViewHolder.

Everything works as expected, but now the problem occurs when I look at the list of the selected imageButton change state for the selected item, and some of the items at the bottom of the list are already displayed selected.

Here is the code

public class ListViewHolder extends RecyclerView.ViewHolder {
    TextView textViewUserName;
    ImageButton imageButtonCheckMark;

    public ListViewHolder(View itemView) {
        super(itemView);
        textViewUserName = (TextView) itemView.findViewById(R.id.textView_user_name);
        imageButtonCheckMark = (ImageButton) itemView.findViewById(R.id.imageButton_add_user);
    }
}

Adapter class

public class ListAdapter extends RecyclerView.Adapter<ListAdapter.ListViewHolder> {

    private LayoutInflater inflater;
    private Context context;
    private List<Metadata> list;
    public static boolean isUserSelected = false;
    ListInterface listener;

    public ListAdapter(Context context, List<Metadata> data, ListInterface listener) {
        Log.d(TAG, "Passed list to adapter : " + data.size());
        inflater = LayoutInflater.from(context);
        this.context = context;
        this.list = data;
        this.listener = listener;
    }

    @Override
    public ListViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = inflater.inflate(R.layout.item_following_people, parent, false);
        return new ListViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ListViewHolder holder, int position) {

        holder.textViewUserName.setText(list.get(position).name);

        holder.imageButtonCheckMark.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (!isUserSelected) {
                    holder.imageButtonCheckMark.setImageResource(R.drawable.checkmark_green);
                    isUserSelected = true;
                } else {
                    holder.imageButtonCheckMark.setImageResource(R.drawable.checkmark_grey);
                    isUserSelected = false;
                }
                listener.onUserSelected(isUserSelected, holder.getLayoutPosition());
            }
        });
    }


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

Class inteface

public interface ListInterface {
    public void onUserSelected(boolean userStatus, int listPosition);
}

Interface callback listener inside operation

// Interface callback listener implemented in the activity class
private ArrayList<Metadata> metadataList = new ArrayList<>();
ArrayList<String> selectedUserIdList = new ArrayList<>();

@Override
public void onUserSelected(boolean isUserSelected, int pos) {
    if (isUserSelected) {
        Log.d(TAG, "Selected user Id: " + metadataList.get(pos).userID);
        followersSelectedIdList.add(metadataList.get(pos).userID);
    } else {
        Log.d(TAG, "Removed user Id: " + metadataList.get(pos).userID);
        followersSelectedIdList.remove(metadataList.get(pos).userID);
    }
}
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, () . onBindViewHolder(), .

+1

, , , onBindViewHolder(), ,

if(yourModel.getIsSelected()){
   // positive view
} else { 
   //negative view
} 
+1

Source: https://habr.com/ru/post/1651138/


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