title: Get button call from another class
body: <p>I have the two classes <code>OrderAdapter.java</code>  <code>OrderActivity.java</code>. In the class <code>OrderAdapter.java</code> is a button and when i click it has to change a textview in the class <code>OrderActivity.java</code>. When i run the app the textview changes one time because of this line which is intend:<br>
  <code>textView_order_price.setText(adapter.totalAmount + "");</code></p>
  
  <p>but when i press the button again it should change the text again but it doesn't. Can you guys help me?</p>
  
  <p><strong>OrderActivity.java</strong></p>
  
  <pre><code>package com.nfc.netvision;
  
  import androidx.appcompat.app.AppCompatActivity;
  import androidx.recyclerview.widget.LinearLayoutManager;
  import androidx.recyclerview.widget.RecyclerView;
  
  import android.os.Bundle;
  import android.view.View;
  import android.widget.TextView;
  
  import java.util.ArrayList;
  
  public class OrderActivity extends AppCompatActivity {
  
      RecyclerView recyclerView;
      TextView textView_order_price;
      ArrayList&lt;ModelOrder&gt; orderArrayList;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_order);
  
          recyclerView = findViewById(R.id.recyclerview_order_scroll);
          textView_order_price = findViewById(R.id.textView_order_price);
  
          orderArrayList = new ArrayList&lt;&gt;();
          orderArrayList.add(new ModelOrder(R.drawable.coke, "Coka Cola", "Eine Cola hält dich wach und schmeckt dazu.", "3",0));
          orderArrayList.add(new ModelOrder(R.drawable.fastfood, "Pommes", "Fritten für die Titten.", "5",0));
          orderArrayList.add(new ModelOrder(R.drawable.water, "Wasser", "Still und sanft, so mag ich es.", "5",0));
          orderArrayList.add(new ModelOrder(R.drawable.burger, "Burger", "Ach mir fällt nichts ein.", "10",0));
  
          LinearLayoutManager layoutManager = new LinearLayoutManager(this);
          RecyclerView.LayoutManager recLiLayoutManager = layoutManager;
  
          recyclerView.setLayoutManager(recLiLayoutManager);
  
          OrderAdapter adapter = new OrderAdapter(this, orderArrayList);
  
          recyclerView.setAdapter(adapter);
          textView_order_price.setText(adapter.totalAmount + "");
          System.out.println(adapter.totalAmount + "TOASBTORT");
  
  
      }
  }
  </code></pre>
  
  <p><strong>OrderAdapter.java</strong></p>
  
  <pre><code>package com.nfc.netvision;
  import android.content.Context;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.ImageView;
  import android.widget.TextView;
  import android.widget.Toast;
  import androidx.annotation.NonNull;
  import androidx.recyclerview.widget.RecyclerView;
  import com.google.firestore.v1.StructuredQuery;
  import java.util.ArrayList;
  public class OrderAdapter extends RecyclerView.Adapter&lt;OrderAdapter.ViewHolder&gt; {
      public int totalAmount;
      private Context mContext;
      private ArrayList&lt;ModelOrder&gt; nList;
      OrderAdapter(Context context, ArrayList&lt;ModelOrder&gt; list) {
          mContext = context;
          nList = list;
      }
      @NonNull
      @Override
      public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
          LayoutInflater layoutInflater = LayoutInflater.from(mContext);
          View view = layoutInflater.inflate(R.layout.recyclerview_order_items, parent, false);
          ViewHolder viewHolder = new ViewHolder(view);
          return viewHolder;
      }
      @Override
      public void onBindViewHolder(@NonNull final ViewHolder holder, int position) {
          final ModelOrder orderItem = nList.get(position);
          ImageView image = holder.item_image;
          final TextView name, place, price;
          name = holder.item_name;
          place = holder.item_place;
          price = holder.item_price;
          image.setImageResource(orderItem.getImage());
          name.setText(orderItem.getName());
          place.setText(orderItem.getPlace());
          price.setText(orderItem.getPrice());
          holder.order_item_minus.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View view) {
                  if(orderItem.getCounter() &gt; 0) {
                      orderItem.setCounter(orderItem.getCounter()-1);
                      holder.order_item_count.setText("" + orderItem.getCounter());
                      calculatePrice(Integer.parseInt((String) price.getText()), false);
                  }
              }
          });
          holder.order_item_plus.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View view) {
                  if(orderItem.getCounter() &lt; 9) {
                      orderItem.setCounter(orderItem.getCounter() + 1);
                      holder.order_item_count.setText("" + orderItem.getCounter());
                      calculatePrice(Integer.parseInt((String) price.getText()), true);
                  }
              }
          });
      }
      @Override
      public int getItemCount() {
          return nList.size();
      }
      public class ViewHolder extends RecyclerView.ViewHolder {
          ImageView item_image;
          TextView item_name, item_place, item_price,order_item_minus,order_item_count, order_item_plus;
          public ViewHolder(@NonNull View itemView) {
              super(itemView);
              item_image = itemView.findViewById(R.id.order_item_image);
              item_name = itemView.findViewById(R.id.order_item_name);
              item_place = itemView.findViewById(R.id.order_item_place);
              item_price = itemView.findViewById(R.id.order_item_price);
              order_item_minus = itemView.findViewById(R.id.order_item_minus);
              order_item_plus = itemView.findViewById(R.id.order_item_plus);
              order_item_count = itemView.findViewById(R.id.order_item_count);
          }
      }
      public void calculatePrice(int pPrice, boolean pUpDown) {
          if(pUpDown) {
              totalAmount = totalAmount + pPrice;
          }
          else {
              totalAmount = totalAmount - pPrice;
          }
          System.out.println(totalAmount);
      }
  }
  </code></pre>