GregorianCalendar lost focus in android api 26

Question

i have an app Android TV with a calendar and can control by d-pad. It work well in android API 25 and when i update it to android API 26 it cannot work as normal. When calendar open first, it focus on current day and i click d-pad then it lost focus. I can't control by d-pad anymore.

Anybody know why please tell me reason and how to resolve it.

here my code:

my calendar adapter: public class RecyclerAdapter extends RecyclerView.Adapter implements View.OnClickListener {

private static final int DAY_OFFSET = 1;
private final String[] months = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
private final int[] daysOfMonth = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
String date_month_year;
private Activity activity;
private List<String> list;
private int daysInMonth;
private int currentDayOfMonth;
private int currentWeekDay;
private CalendarAdapter.IChangeMonth iChangeMonth;
private int currentMonth;
private Calendar calendar;

public RecyclerAdapter(Context context, int textViewResourceId, int month, int year, CalendarAdapter.IChangeMonth iChangeMonth) {
    super();
    this.activity = (Activity) context;
    this.list = new ArrayList<String>();
    calendar = Calendar.getInstance();
    setCurrentDayOfMonth(calendar.get(Calendar.DAY_OF_MONTH));
    setCurrentWeekDay(calendar.get(Calendar.DAY_OF_WEEK));
    this.iChangeMonth = iChangeMonth;

    // Print Month
    printMonth(month, year);
}

private String getMonthAsString(int i) {
    return months[i];
}

private int getNumberOfDaysOfMonth(int i) {
    return daysOfMonth[i];
}

private void printMonth(int mm, int yy) {
    int trailingSpaces = -1;
    int daysInPrevMonth = 0;
    int prevMonth = 0;
    int prevYear = 0;
    int nextMonth = 0;
    int nextYear = 0;

    currentMonth = mm - 1;
    daysInMonth = getNumberOfDaysOfMonth(currentMonth);


    // Gregorian GridCalendar : MINUS 1, set to FIRST OF MONTH
    GregorianCalendar cal = new GregorianCalendar(yy, currentMonth, 1);

    if (currentMonth == 11) {
        prevMonth = currentMonth - 1;
        daysInPrevMonth = getNumberOfDaysOfMonth(prevMonth);
        nextMonth = 0;
        prevYear = yy;
        nextYear = yy + 1;
    } else if (currentMonth == 0) {
        prevMonth = 11;
        prevYear = yy - 1;
        nextYear = yy;
        daysInPrevMonth = getNumberOfDaysOfMonth(prevMonth);
        nextMonth = 1;
    } else {
        prevMonth = currentMonth - 1;
        nextMonth = currentMonth + 1;
        nextYear = yy;
        prevYear = yy;
        daysInPrevMonth = getNumberOfDaysOfMonth(prevMonth);
    }

    int currentWeekDay = cal.get(Calendar.DAY_OF_WEEK) - 1;
    trailingSpaces = currentWeekDay;

    if (cal.isLeapYear(cal.get(Calendar.YEAR)) && mm == 1) {
        ++daysInMonth;
    }

    // Trailing Month days
    for (int i = 0; i < trailingSpaces; i++) {
        list.add(String.valueOf((daysInPrevMonth - trailingSpaces + DAY_OFFSET) + i) + "-GREY" + "-" + getMonthAsString(prevMonth) + "-" + prevYear + "-" + (prevMonth + 1));
    }

    // Current Month Days
    for (int i = 1; i <= daysInMonth; i++) {
        if (i == getCurrentDayOfMonth())
            list.add(String.valueOf(i) + "-DARKRED" + "-" + getMonthAsString(currentMonth) + "-" + yy + "-" + (currentMonth + 1));
        else
            list.add(String.valueOf(i) + "-WHITE" + "-" + getMonthAsString(currentMonth) + "-" + yy + "-" + (currentMonth + 1));
    }

    // Leading Month days
    for (int i = 0; i < list.size() % 7; i++) {
        list.add(String.valueOf(i + 1) + "-GREY" + "-" + getMonthAsString(nextMonth) + "-" + nextYear + "-" + (nextMonth + 1));
    }
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    return new ViewHolder(LayoutInflater.from(activity).inflate(R.layout.calendar_item, parent, false));
}

@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
    final String[] day_color = list.get(position).split("-");
    String theDay = day_color[0];
    String theYear = day_color[3];
    String monthNumber = day_color[4];

    // Set the Day GridCell
    holder.btnGridCell.setText(theDay);
    holder.btnGridCell.setTag(theDay + "/" + monthNumber + "/" + theYear);

    if (day_color[1].equals("GREY")) {
        holder.btnGridCell.setTextColor(0xffe95451);
    }

    if (day_color[1].equals("DARKRED") && currentMonth == calendar.get(Calendar.MONTH)) {
        holder.btnGridCell.requestFocus();
      holder.btnGridCell.setTextColor(activity.getResources().getColor(R.color.current_day));
    } else if (day_color[1].equals("WHITE") && holder.btnGridCell.getText().equals("1") && currentMonth != calendar.get(Calendar.MONTH)) {
        holder.btnGridCell.requestFocus();
    }

    holder.btnGridCell.setOnClickListener(this);
    holder.itemView.setOnClickListener(this);
    holder.btnGridCell.setOnLongClickListener(v -> {
        if ((position % 7) == 0) {
            iChangeMonth.changePrevMonth();
        }
        if ((position % 7) == 6) {
            iChangeMonth.changeNextMonth();
        }
        return false;
    });
    holder.btnGridCell.setOnKeyListener((v, keyCode, event) -> {
        if (event.getAction() == KeyEvent.ACTION_DOWN) {
            switch (keyCode) {
                case KeyEvent.KEYCODE_ENTER:
                case KeyEvent.KEYCODE_DPAD_CENTER:
                    date_month_year = (String) v.getTag();
                    try {
                        SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy", Locale.getDefault());
                        Date date = formatter.parse(date_month_year);
                        iChangeMonth.choseDate(date.getTime());
                    } catch (ParseException e) {
                        e.printStackTrace();
                        Toast.makeText(activity, e.getMessage(), Toast.LENGTH_SHORT).show();
                    }
                    break;
                case KeyEvent.KEYCODE_DPAD_LEFT:
                    if ((position % 7) == 0) {
                        iChangeMonth.changePrevMonth();
                    }
                    break;
                case KeyEvent.KEYCODE_DPAD_RIGHT:
                    if ((position % 7) == 6) {
                        iChangeMonth.changeNextMonth();
                    }
                    break;
            }
            return false;
        }
        if (event.getAction() == KeyEvent.ACTION_UP) {
            Log.e("eee", "action up: " + holder.getAdapterPosition());
            return false;
        }
        return false;
    });
}

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

@Override
public void onClick(View view) {
    date_month_year = (String) view.getTag();
    try {
        SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy", Locale.getDefault());
        Date date = formatter.parse(date_month_year);
        iChangeMonth.choseDate(date.getTime());
    } catch (ParseException e) {
        e.printStackTrace();
        Toast.makeText(activity, e.getMessage(), Toast.LENGTH_SHORT).show();
    }
}

public int getCurrentDayOfMonth() {
    return currentDayOfMonth;
}

private void setCurrentDayOfMonth(int currentDayOfMonth) {
    this.currentDayOfMonth = currentDayOfMonth;
}

public int getCurrentWeekDay() {
    return currentWeekDay;
}

public void setCurrentWeekDay(int currentWeekDay) {
    this.currentWeekDay = currentWeekDay;
}

public class ViewHolder extends RecyclerView.ViewHolder {
    private Button btnGridCell;
    private View itemView;

    public ViewHolder(View itemView) {
        super(itemView);
        this.itemView = itemView;
        btnGridCell = (Button) itemView.findViewById(R.id.calendar_day_gridcell);
    }
}

}