RecyclerView shows previous values entered in an EditText in new rows

Question

I'm creating an android app, in which I'm using recyclerView and the row of recyclerView is having editText.

This is my ReadingAdapter class

public class ReadingAdapter extends RecyclerView.Adapter<ReadingAdapter.ViewHolder>  implements AdapterView.OnItemSelectedListener {

    Context context;
    String valOpenReading, valClosReading, valConsumption;
    private List<ReadingData> readingList;
    static String[] arrValOpenRead, arrValClosRead, arrValConsumption;
    public ReadingAdapter(Context context, List<ReadingData> readingList) {
        this.context = context;
        this.readingList = readingList;

        arrValOpenRead = new String[readingList.size()];
        arrValClosRead = new String[readingList.size()];
        arrValConsumption = new String[readingList.size()];
    }

    @Override
    public ReadingAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.reading_sheet_layout, parent, false);
        return new ReadingAdapter.ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(final ReadingAdapter.ViewHolder holder, final int position) {
        ReadingData tempData = readingList.get(position);
        holder.pdtName.setText(tempData.pdtName);
        holder.keyId.setText("Key "+tempData.keyId);

        holder.etClosRead.addTextChangedListener(new TextWatcher() {
            boolean ignore = false;
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }
            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {

            }
            @Override
            public void afterTextChanged(Editable s) {
                if (ignore)
                    return;
                ignore = true;
                valOpenReading = holder.etOpenRead.getText().toString();
                arrValOpenRead[position] = valOpenReading;
                valClosReading = s.toString().equals("") ? "0": s.toString();
                arrValClosRead[position] = valClosReading;
                if (!valOpenReading.equals("")) {
                    if (Integer.parseInt(valClosReading) < Integer.parseInt(valOpenReading)) {
                        Toast.makeText(context, "Check once! closing reading should be more than opening reading!", Toast.LENGTH_LONG).show();
                        valConsumption = "0";
                        holder.consumption.setText("");
                    } else {
                        valConsumption = (Integer.parseInt(valClosReading) - Integer.parseInt(valOpenReading))+"";
                        arrValConsumption[position] = valConsumption;
                        holder.consumption.setText(valConsumption);
                    }
                } else
                    Toast.makeText(context, "Please fill the opening reading!", Toast.LENGTH_SHORT).show();
                ignore = false;
            }
        });
    }

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

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {

    }

    public class ViewHolder extends RecyclerView.ViewHolder{
        TextView pdtName, keyId, consumption;
        EditText etOpenRead, etClosRead;
        public ViewHolder(View view) {
            super(view);
            pdtName = (TextView)view.findViewById(R.id.txt_list_pdt_supp);
            keyId = (TextView)view.findViewById(R.id.key_set);
            etOpenRead = (EditText)view.findViewById(R.id.open_val_set);
            etClosRead = (EditText)view.findViewById(R.id.clos_val_set);
            consumption = (TextView)view.findViewById(R.id.consumption_val);
        }
    }
}

This is my ReadingData.java

public class ReadingData {
    String pdtName, keyId, openReading, closReading, consumption;
    public ReadingData(String pdtName, String keyId) {
        this.pdtName = pdtName;
        this.keyId = keyId;
    }
}

Here, if I enter value in the starting items of the recyclerView then as I scroll up the items to the bottom of the list, the last item will have that value.

Please ignore the quality of image as we can't upload above of 2MiB of snap.

Here the views are recycled as the list is scrolled. How to prevent the copying values to the other item in the list.

And that Toast is also repeated several times. How to stop this.

update: By the suggetion of LQ Gioan through the SO question How ListView's recycling mechanism works , I got the logic how ListView actually works with recycling of views.

But I'm not sure whether the recyclerView also works same.

But here in my case, how can I implement this process. pls someone help me here.

Answer 1

RecyclerView reuse views, in fact it only generate the as many as views that is visible on the screen. so it's expected if you can see a value you set for other rows

The solution would be set all attributes of the view that you are changing to default or whatever the row should present from your data set

So put addTextChangedListener insode ViewHolder constructor(you can get position by calling getAdapterPosition()) for better performance and set the editText value inside onBindViewHolder method from your data set