change background of all textviews in recyclerview from activity and not from adapter - android-recyclerview

Question

I have a recyclerview with a textview and the clicked textview gets a background around it.I also have a button within the activity which should put a background to all the items in the recyclerview ie..to show all selected.I am putting my activity and adapter code.please help me
my activity code
set_all_days.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
CommonUtility.selectedDays.clear();
CommonUtility.selectedDays.addAll(daysList);
//loadDays();
}
});
my adapter
public class DaysAdapter<T> extends RecyclerView.Adapter<DaysAdapter.ViewHolder> {
private ArrayList<String> list=new ArrayList<>();
private Context mContext;
private RecyclerViewClickListener mListener;
public DaysAdapter(ArrayList<String> data, Context context, RecyclerViewClickListener listener) {
list = data;
//languageListFiltered = filteredData;
mContext = context;
mListener = listener;
}
#Override
public void onBindViewHolder(DaysAdapter.ViewHolder viewHolder, final int position) {
viewHolder.titleTextView.setText(list.get(position));
// viewHolder.lang_radio.setChecked(position == mSelectedItem);
}
#Override
public int getItemCount() {
return list.size();
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
LayoutInflater inflater = LayoutInflater.from(mContext);
final View view = inflater.inflate(R.layout.days_list_item, viewGroup, false);
return new ViewHolder(view);
}
class ViewHolder extends RecyclerView.ViewHolder {
public TextView titleTextView;
public ViewHolder(final View inflate) {
super(inflate);
titleTextView = (TextView)inflate.findViewById(R.id.text_day);
View.OnClickListener clickListener = new View.OnClickListener() {
#Override
public void onClick(View v) {
if(!CommonUtility.selectedDays.contains(titleTextView.getText().toString()))
{
titleTextView.setBackground(mContext.getResources().getDrawable(R.drawable.green_circle));
titleTextView.setTextColor(mContext.getResources().getColor(R.color.white));
CommonUtility.selectedDays.add(titleTextView.getText().toString());
Log.d("added",titleTextView.getText().toString());
}
else
{
int index=CommonUtility.selectedDays.indexOf(titleTextView.getText().toString());
CommonUtility.selectedDays.remove(index);
titleTextView.setBackground(null);
Log.d("removed",titleTextView.getText().toString());
titleTextView.setTextColor(mContext.getResources().getColor(R.color.black));
}
}
};
itemView.setOnClickListener(clickListener);
titleTextView.setOnClickListener(clickListener);
}
}
}