[embedyt] https://www.youtube.com/watch?v=lAGI6jGS4vs[/embedyt]
Links & DependenciesNoteAdapter.javaMainActivity.javaactivity_main.xmlnote_item.xmlNote.javanew_note_menu.xml
package com.codinginflow.firebaseui_firestoreexample;

import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.firebase.ui.firestore.FirestoreRecyclerAdapter;
import com.firebase.ui.firestore.FirestoreRecyclerOptions;

public class NoteAdapter extends FirestoreRecyclerAdapter<Note, NoteAdapter.NoteHolder> {

    public NoteAdapter(@NonNull FirestoreRecyclerOptions<Note> options) {
        super(options);
    }

    @Override
    protected void onBindViewHolder(@NonNull NoteHolder holder, int position, @NonNull Note model) {
        holder.textViewTitle.setText(model.getTitle());
        holder.textViewDescription.setText(model.getDescription());
        holder.textViewPriority.setText(String.valueOf(model.getPriority()));
    }

    @NonNull
    @Override
    public NoteHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.note_item,
                parent, false);
        return new NoteHolder(v);
    }

    class NoteHolder extends RecyclerView.ViewHolder {
        TextView textViewTitle;
        TextView textViewDescription;
        TextView textViewPriority;

        public NoteHolder(View itemView) {
            super(itemView);
            textViewTitle = itemView.findViewById(R.id.text_view_title);
            textViewDescription = itemView.findViewById(R.id.text_view_description);
            textViewPriority = itemView.findViewById(R.id.text_view_priority);
        }
    }
}
package com.codinginflow.firebaseui_firestoreexample;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

import com.firebase.ui.firestore.FirestoreRecyclerOptions;
import com.google.firebase.firestore.CollectionReference;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.Query;

public class MainActivity extends AppCompatActivity {
    private FirebaseFirestore db = FirebaseFirestore.getInstance();
    private CollectionReference notebookRef = db.collection("Notebook");

    private NoteAdapter adapter;

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

        setUpRecyclerView();
    }

    private void setUpRecyclerView() {
        Query query = notebookRef.orderBy("priority", Query.Direction.DESCENDING);

        FirestoreRecyclerOptions<Note> options = new FirestoreRecyclerOptions.Builder<Note>()
                .setQuery(query, Note.class)
                .build();

        adapter = new NoteAdapter(options);

        RecyclerView recyclerView = findViewById(R.id.recycler_view);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setAdapter(adapter);
    }

    @Override
    protected void onStart() {
        super.onStart();
        adapter.startListening();
    }

    @Override
    protected void onStop() {
        super.onStop();
        adapter.stopListening();
    }
}
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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"
    tools:context=".MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/button_add_note"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_margin="16dp"
        android:src="@drawable/ic_add" />

</android.support.design.widget.CoordinatorLayout>
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginEnd="8dp"
    android:layout_marginStart="8dp"
    android:layout_marginTop="8dp"
    app:cardBackgroundColor="#FFFFE8">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:padding="8dp">

        <TextView
            android:id="@+id/text_view_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentStart="true"
            android:layout_toStartOf="@id/text_view_priority"
            android:ellipsize="end"
            android:maxLines="1"
            android:text="Title"
            android:textAppearance="@style/TextAppearance.AppCompat.Large" />

        <TextView
            android:id="@+id/text_view_priority"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentEnd="true"
            android:layout_alignParentTop="true"
            android:text="1"
            android:textAppearance="@style/TextAppearance.AppCompat.Large" />

        <TextView
            android:id="@+id/text_view_description"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentStart="true"
            android:layout_below="@id/text_view_title"
            android:text="Description" />

    </RelativeLayout>

</android.support.v7.widget.CardView>
package com.codinginflow.firebaseui_firestoreexample;

public class Note {
    private String title;
    private String description;
    private int priority;

    public Note() {
        //empty constructor needed
    }

    public Note(String title, String description, int priority) {
        this.title = title;
        this.description = description;
        this.priority = priority;
    }

    public String getTitle() {
        return title;
    }

    public String getDescription() {
        return description;
    }

    public int getPriority() {
        return priority;
    }
}
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/save_note"
        android:icon="@drawable/ic_save"
        android:title="Save"
        app:showAsAction="ifRoom" />
</menu>