Java – recyclerview displays the deleted data on the list

I have implemented recyclerview with inbox style sliding view. When swiping my card, I deleted the list item using the following method:

public void removeItem(int position) {
    countries.remove(position);
    notifyItemRemoved(position);
}

Similarly, when I press fab, I use this method to add data,

public void addItem(String country) {
    countries.add(country);
    notifyItemInserted(countries.size());
}

However, when I delete a data item by sliding, it will be deleted from the ArrayList and recyclerview lists, but when I add data through fab, the deleted data will still be displayed in the list. I checked the ArrayList dataset. This is expected

In the screenshot above, you can see that string test is the newly added data. I have deleted the last two lines of data. It is displayed randomly

Complete code for my adapter and activity

public class DataAdapter extends RecyclerView.Adapter<DataAdapter.ViewHolder> {
    private ArrayList<String> countries;
    private TextView tv_country;


    public DataAdapter(ArrayList<String> countries) {
        this.countries = countries;
    }

    @Override
    public DataAdapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.row_layout, viewGroup, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(DataAdapter.ViewHolder viewHolder, int i) {

        tv_country.setText(countries.get(i));
    }

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

    public void addItem(String country) {
        countries.add(country);
        notifyItemInserted(countries.size());
    }

    public void removeItem(int position) {
        countries.remove(position);
        notifyItemRemoved(position);
    }
    public class ViewHolder extends RecyclerView.ViewHolder{
        public ViewHolder(View view) {
            super(view);

            tv_country = (TextView)view.findViewById(R.id.tv_country);
        }
    }
}

MainActivity.java

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private ArrayList<String> countries =  new ArrayList<>();
    private DataAdapter adapter;
    private RecyclerView recyclerView;
    private  RecyclerView.LayoutManager layoutManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        initViews();
    }

    private void initViews(){
        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(this);
        recyclerView = (RecyclerView)findViewById(R.id.card_recycler_view);
        recyclerView.setHasFixedSize(true);
        layoutManager = new linearlayoutmanager(getApplicationContext());
        recyclerView.setLayoutManager(layoutManager);
        adapter = new DataAdapter(countries);
        recyclerView.setAdapter(adapter);
        countries.add("Australia");
        countries.add("India");
        countries.add("United States of America");
        countries.add("Germany");
        countries.add("Russia");
        adapter.notifyDataSetChanged();

        itemtouchhelper.SimpleCallback simpleItemTouchCallback = new itemtouchhelper.SimpleCallback(0, itemtouchhelper.LEFT | itemtouchhelper.RIGHT) {
            @Override
            public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
                return false;
            }

            @Override
            public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
                int position = viewHolder.getAdapterPosition();

                if (direction == itemtouchhelper.LEFT){

                    adapter.removeItem(position);

                }
            }

            @Override
            public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
                Paint p = new Paint();
                Bitmap icon;
                if(actionState == itemtouchhelper.ACTION_STATE_SWIPE){

                    View itemView = viewHolder.itemView;

                    if(dX > 0){
                        p.setColor(Color.parseColor("#388E3C"));
                        c.drawRect((float) itemView.getLeft(), (float) itemView.getTop(), dX,(float) itemView.getBottom(), p);
                        icon = BitmapFactory.decodeResource(
                                getResources(), R.drawable.ic_edit_white);
                        float height = (float) itemView.getBottom() - (float) itemView.getTop();
                        float width = height / 3;
                        RectF dest = new RectF((float) itemView.getLeft() + width ,(float) itemView.getTop() + width,(float) itemView.getLeft()+ width+width,(float)itemView.getBottom() - width);
                        c.drawBitmap(icon,null,dest,p);
                    } else {
                        p.setColor(Color.parseColor("#D32F2F"));
                        c.drawRect((float) itemView.getRight() + dX, (float) itemView.getTop(),(float) itemView.getRight(), (float) itemView.getBottom(), p);
                        icon = BitmapFactory.decodeResource(getResources(), R.drawable.ic_delete_white);
                        float height = (float) itemView.getBottom() - (float) itemView.getTop();
                        float width = height / 3;
                        RectF dest = new RectF((float) itemView.getRight() - width - width ,(float) itemView.getTop() + width,(float) itemView.getRight() - width,(float)itemView.getBottom() - width);
                        c.drawBitmap(icon,null,dest,p);
                    }
                }

                super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
            }
        };

        itemtouchhelper itemtouchhelper = new itemtouchhelper(simpleItemTouchCallback);
        itemtouchhelper.attachToRecyclerView(recyclerView);

    }

    @Override
    public void onClick(View v) {

        switch (v.getId()){
            case R.id.fab:
                adapter.addItem("Test");
                Log.d("Raj",countries.toString());
                break;
        }
    }
}

What have I tried

I tried using notifyitemrangechanged() like this:

public void removeItem(int position) {
    countries.remove(position);
    notifyItemRemoved(position);
    notifyItemRangeChanged(position, countries.size());
}

resolvent:

I'm not sure this will solve your problem, but one thing is incorrect is how you bind data. TV_ Country should not be part of the DataAdapter; It should be part of every viewholder. One of the reasons we use viewholder mode is to keep a simple reference to the views in each row

Your bind method should be similar to:

public void onBindViewHolder(DataAdapter.ViewHolder viewHolder, int i) {
    viewHolder.tv_country.setText(countries.get(i));
}

And ensure that TV_ Country is set as the public field of the internal viewholder class

public class ViewHolder extends RecyclerView.ViewHolder{
    public TextView tv_country;
    public ViewHolder(View view) {
        super(view);
        tv_country = (TextView) view.findViewById(R.id.tv_country);
    }
}