Firebase Auth with Facebook a Android application

activity_login.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="tech.alvarez.today.LoginActivity">

    <com.facebook.login.widget.LoginButton
        android:id="@+id/loginButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:paddingBottom="10dp"
        android:paddingTop="10dp" />

    <ProgressBar
        android:id="@+id/progressBar"
        style="?android:attr/progressBarStyleLarge"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:indeterminate="true"
        android:visibility="gone" />

</RelativeLayout>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="tech.alvarez.today.MainActivity">

    <TextView
        android:id="@+id/nameTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="Nombre"
        android:textSize="20sp" />

    <TextView
        android:id="@+id/emailTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@id/nameTextView"
        android:layout_centerHorizontal="true"
        android:text="Email"
        android:textSize="16sp" />

    <TextView
        android:id="@+id/uidTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/nameTextView"
        android:layout_centerHorizontal="true"
        android:text="UID"
        android:textSize="14sp" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:onClick="logout"
        android:text="@string/logout" />
</RelativeLayout>

build.gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion "24.0.0"

    defaultConfig {
        applicationId "tech.alvarez.today"
        minSdkVersion 15
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:24.0.0'

    compile 'com.facebook.android:facebook-android-sdk:[4,5)'

    compile 'com.google.firebase:firebase-core:9.0.2'
    compile 'com.google.firebase:firebase-auth:9.0.2'
}

apply plugin: 'com.google.gms.google-services'

colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#4CAF50</color>
    <color name="colorPrimaryDark">#388E3C</color>
    <color name="colorAccent">#FFD740</color>
</resources>

LoginActivity.java

package tech.alvarez.today;

import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.facebook.AccessToken;
import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;
import com.facebook.login.LoginResult;
import com.facebook.login.widget.LoginButton;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthCredential;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FacebookAuthProvider;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;

import java.util.Arrays;

public class LoginActivity extends AppCompatActivity {

    private LoginButton loginButton;
    private CallbackManager callbackManager;

    private FirebaseAuth firebaseAuth;
    private FirebaseAuth.AuthStateListener firebaseAuthListener;

    private ProgressBar progressBar;

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

        progressBar = (ProgressBar) findViewById(R.id.progressBar);

        callbackManager = CallbackManager.Factory.create();

        loginButton = (LoginButton) findViewById(R.id.loginButton);

        loginButton.setReadPermissions(Arrays.asList("email"));

        loginButton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {
                handleFacebookAccessToken(loginResult.getAccessToken());
            }

            @Override
            public void onCancel() {
                Toast.makeText(getApplicationContext(), R.string.cancel_login, Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onError(FacebookException error) {
                Toast.makeText(getApplicationContext(), R.string.error_login, Toast.LENGTH_SHORT).show();
            }
        });

        firebaseAuth = FirebaseAuth.getInstance();
        firebaseAuthListener = new FirebaseAuth.AuthStateListener() {
            @Override
            public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
                FirebaseUser user = firebaseAuth.getCurrentUser();
                if (user != null) {
                    goMainScreen();
                }
            }
        };
    }

    private void handleFacebookAccessToken(AccessToken accessToken) {
        progressBar.setVisibility(View.VISIBLE);
        loginButton.setVisibility(View.GONE);

        AuthCredential credential = FacebookAuthProvider.getCredential(accessToken.getToken());
        firebaseAuth.signInWithCredential(credential).addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
            @Override
            public void onComplete(@NonNull Task<AuthResult> task) {
                if (!task.isSuccessful()) {
                    Toast.makeText(getApplicationContext(), R.string.firebase_error_login, Toast.LENGTH_LONG).show();
                }
                progressBar.setVisibility(View.GONE);
                loginButton.setVisibility(View.VISIBLE);
            }
        });
    }

    private void goMainScreen() {
        Intent intent = new Intent(this, MainActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(intent);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        callbackManager.onActivityResult(requestCode, resultCode, data);
    }

    @Override
    protected void onStart() {
        super.onStart();
        firebaseAuth.addAuthStateListener(firebaseAuthListener);
    }

    @Override
    protected void onStop() {
        super.onStop();
        firebaseAuth.removeAuthStateListener(firebaseAuthListener);
    }
}

MainActivity.java

package tech.alvarez.today;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;

import com.facebook.login.LoginManager;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;

public class MainActivity extends AppCompatActivity {

    private TextView nameTextView;
    private TextView emailTextView;
    private TextView uidTextView;

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

        nameTextView = (TextView) findViewById(R.id.nameTextView);
        emailTextView = (TextView) findViewById(R.id.emailTextView);
        uidTextView = (TextView) findViewById(R.id.uidTextView);

        FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();

        if (user != null) {
            String name = user.getDisplayName();
            String email = user.getEmail();
            Uri photoUrl = user.getPhotoUrl();
            String uid = user.getUid();

            nameTextView.setText(name);
            emailTextView.setText(email);
            uidTextView.setText(uid);
        } else {
            goLoginScreen();
        }
    }

    private void goLoginScreen() {
        Intent intent = new Intent(this, LoginActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(intent);
    }

    public void logout(View view) {
        FirebaseAuth.getInstance().signOut();
        LoginManager.getInstance().logOut();
        goLoginScreen();
    }
}

strings.xml

<resources>
    <string name="app_name">Today</string>

    <string name="facebook_app_id">TU_ID_APP</string>

    <string name="welcome">Bienvenido</string>
    <string name="cancel_login">Se canceló la operación</string>
    <string name="error_login">Ocurrió un error al ingresar</string>
    <string name="logout">Cerrar sesión</string>
    <string name="firebase_error_login">Error al iniciar sesión en Firebase</string>
</resources>

TodayApp.java

package tech.alvarez.today;

import android.app.Application;

import com.facebook.FacebookSdk;
import com.facebook.appevents.AppEventsLogger;

/**
 * Created by Daniel Alvarez on 29/6/16.
 * Copyright © 2016 Alvarez.tech. All rights reserved.
 */
public class TodayApp extends Application {

    @Override
    public void onCreate() {
        super.onCreate();
        FacebookSdk.sdkInitialize(getApplicationContext());
        AppEventsLogger.activateApp(this);
    }
}

Thank's a lot 👍

el todayapp.java es otra activity?
que funcion cumple?

thanks!

great! some deprecation happens