Estoy tratando de abrir diálogo pero guardo en conseguir error de compilación de `Builder (android.content.Context) en el constructor no puede ser aplicada a la actividad

Ronnie:

El siguiente código muestra RecyclerViewy actividad subyacente es la disposición Tab. En este momento el código de forma en que se Recibo un error por el que declaro el AlertDialogerror dice Builder cannot be applied to the Classsi uso Contexto de la aplicación se bloquea. He utilizado el mismo código de antes, pero con Firestore Recycler Adaptery TabLayout. Esta pregunta no es un duplicado, null pointer java/lang/nullpointerexceptiones demasiado general. He pasado por todos ellos.

public class RecyclerAdapter extends FirestoreRecyclerAdapter<Items, 
RecyclerAdapter.MyViewHolder> {

Context context;


public RecyclerAdapter(@NonNull FirestoreRecyclerOptions<Items> options) 
{
    super(options);
}

@Override
protected void onBindViewHolder(@NonNull MyViewHolder holder, final int 
position, @NonNull final Items model) {
    holder.name.setText(model.getName());
    holder.category.setText(model.getCategory());
    holder.price.setText(model.getPrice());
    holder.manu.setText(model.getManufacturer());


    Picasso.get()
            .load(model.getImage())
            .fit()
            .centerCrop()
            .into(holder.Thumbnail);


    holder.addtocart.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            showAddToCartDialog(model);
        }
    });
}

@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int 
 viewType) {
    View view;
    LayoutInflater mInflater = LayoutInflater.from(parent.getContext());
    view = mInflater.inflate(R.layout.activity_adapter, parent, false);
    return new MyViewHolder(view);
}

class MyViewHolder extends RecyclerView.ViewHolder {
    public TextView name;
    public TextView category;
    public ImageView Thumbnail;
    public TextView price;
    public TextView manu;
    public Button addtocart;

    public MyViewHolder(View itemView) {
        super(itemView);
        name = itemView.findViewById(R.id.rowname);
        category = itemView.findViewById(R.id.categorie);
        Thumbnail = itemView.findViewById(R.id.thumbnail);
        price = itemView.findViewById(R.id.price);
        manu = itemView.findViewById(R.id.manu);
        addtocart = itemView.findViewById(R.id.cartbutton);
    }
}

public void showAddToCartDialog(final Items items) {
    View view;

    AlertDialog.Builder builder = new 
    AlertDialog.Builder(RecyclerAdapter.this);
    LayoutInflater lflator = LayoutInflater.from(context);
    view = lflator.inflate(R.layout.add_to_cart_layout, null);

    ImageView image_product_dialogue = 
    view.findViewById(R.id.image_cart_product);
    TextView textView_product_dialogue = 
    view.findViewById(R.id.text_cart_product);
    RadioButton nairobi = view.findViewById(R.id.radio_nairobi);
    RadioButton mombasa = view.findViewById(R.id.radio_mombasa);
    RadioButton kisumu = view.findViewById(R.id.radio_kisumu);
    RadioButton nakuru = view.findViewById(R.id.radio_nakuru);
    RadioButton express = view.findViewById(R.id.radio_ex);
    RadioButton tomorow = view.findViewById(R.id.radio_tomo);
    final ElegantNumberButton text_count = 
    view.findViewById(R.id.text_count);

    express.setOnCheckedChangeListener(new 
    CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean 
        isChecked) {
            if (isChecked) {
                Items.delivery = 0;
            }
          }
      });

    tomorow.setOnCheckedChangeListener(new 
    CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean 
         isChecked) {
            if (isChecked)
                Items.delivery = 1;

        }
    });

    nairobi.setOnCheckedChangeListener(new 
    CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean 
   isChecked) {
            if (isChecked)
                Items.location = 0;

        }
    });
    mombasa.setOnCheckedChangeListener(new 
    CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean 
   isChecked) {
            if (isChecked)
                Items.location = 1;

        }
    });
    kisumu.setOnCheckedChangeListener(new 
    CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean 
  isChecked) {
            if (isChecked)
                Items.location = 2;

        }
    });
    nakuru.setOnCheckedChangeListener(new 
    CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean 
   isChecked) {
            if (isChecked)
                Items.location = 3;

        }
    });

    Picasso.get()
            .load(items.getImage())
            .fit()
            .centerCrop()
            .into(image_product_dialogue);
    textView_product_dialogue.setText(items.getName());

    builder.setView(view);

    builder.setNegativeButton("ADD TO CART", new 
    DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {

            // showConfirmDialogue(position, text_count.getNumber(), 
   text_count.getNumber());
            dialog.dismiss();

        }
    });


    builder.show();

  }

 }

Kelvin:

Pase contexto de actividad en el constructor y el uso de ese contexto para crear diálogo. algo como..

public RecyclerAdapter(@NonNull FirestoreRecyclerOptions<Items> options,Activity context) 
{
    super(options);
    this.context=context;
}