How to pass edit text value from adapter to activity?

Question

I have a recycler view adapter which takes input from user in edittext. I want to pass those values as a list back to the activity in which the recycler view is present. I need this list in activity to send as a parameter to api through retrofit.

Answer 1

1. Create an interface like this:

interface IList {
   void addToList(String editTextValue);
}

2. Implement this interface in your Activity:

class MainActivity extends AppCompatActivity implements IList {

    @Override
    public void addToList(String editTextValue) {
        //TODO("logic for adding to list and sending")
    }
}

3. Add to Adapter's constructor Activity, that implementing IList interface, as paramert:

public Adapter(IList listener){
   this.listener = listener;
}

4. Execute addToList method in your adapter:

    @Override 
    public void onBindViewHolder(NewViewHolder holder, int position) {
        holder.sendButton.setOnClickListener .setOnClickListener(v -> {
            String newText = holder.editText.text.toString()
            listener.addToList(newText)
        });
    }

Answer 2

There's a working sample.

MainActivity.java

```    
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.inputmethod.EditorInfo;
import android.widget.EditText;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.RecyclerView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Adapter adapter = new Adapter();
        RecyclerView recyclerView = findViewById(R.id.recyclerView);
        recyclerView.setAdapter(adapter);

        EditText editText = findViewById(R.id.editText);
        editText.setOnEditorActionListener((textView, actionId, keyEvent) -> {
            boolean handled = false;
            if (actionId == EditorInfo.IME_ACTION_DONE) {
                // add item
                adapter.addItem(editText.getText().toString());
                // clear text input
                textView.setText("");
                handled = true;
            }
            return handled;
        });
    }
}
    
```

activity_main.xml

```
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/editText"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:hint="Insert text.."
        android:imeOptions="actionDone"
        android:inputType="text"
        app:layout_constraintBottom_toTopOf="@+id/recyclerView"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.0"
        app:layout_constraintVertical_chainStyle="packed" />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/editText" />

</androidx.constraintlayout.widget.ConstraintLayout>

```

Adapter.java

```    
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import java.util.ArrayList;
import java.util.List;

public class Adapter extends RecyclerView.Adapter<Adapter.ViewHolder> {

    private List<String> items = new ArrayList<>();

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

    @Override
    public void onBindViewHolder(@NonNull Adapter.ViewHolder holder, int position) {
        String currentItem = items.get(position);
        holder.textView.setText(currentItem);
    }

    public void addItem(String item) {
        // add at first position - replace with your desired index
        int index = 0;
        this.items.add(index, item);
        notifyItemInserted(index);
    }

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

    public class ViewHolder extends RecyclerView.ViewHolder {
        protected TextView textView;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            textView = itemView.findViewById(android.R.id.text1);
        }
    }
}

You can use the "done" key on the keyboard to notify the adapter that an item has been added.
To display the "done" button in the xml it is necessary to use these two instructions in the edittext

    android:imeOptions="actionDone"
    android:inputType="text"