FacebookLoginActivity.java

/**
 * Copyright 2021 Google Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.firebase.quickstart.auth;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;

import androidx.annotation.NonNull;

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;

/**
 * Demonstrate Firebase Authentication using a Facebook access token.
 */
public class FacebookLoginActivity extends Activity {

    private static final String TAG = "FacebookLogin";

    // [START declare_auth]
    private FirebaseAuth mAuth;
    // [END declare_auth]

    private CallbackManager mCallbackManager;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // [START initialize_auth]
        // Initialize Firebase Auth
        mAuth = FirebaseAuth.getInstance();
        // [END initialize_auth]

        // [START initialize_fblogin]
        // Initialize Facebook Login button
        mCallbackManager = CallbackManager.Factory.create();
        LoginButton loginButton = findViewById(R.id.button_sign_in);
        loginButton.setReadPermissions("email", "public_profile");
        loginButton.registerCallback(mCallbackManager, new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {
                Log.d(TAG, "facebook:onSuccess:" + loginResult);
                handleFacebookAccessToken(loginResult.getAccessToken());
            }

            @Override
            public void onCancel() {
                Log.d(TAG, "facebook:onCancel");
            }

            @Override
            public void onError(FacebookException error) {
                Log.d(TAG, "facebook:onError", error);
            }
        });
        // [END initialize_fblogin]
    }

    // [START on_start_check_user]
    @Override
    public void onStart() {
        super.onStart();
        // Check if user is signed in (non-null) and update UI accordingly.
        FirebaseUser currentUser = mAuth.getCurrentUser();
        updateUI(currentUser);
    }
    // [END on_start_check_user]

    // [START on_activity_result]
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        // Pass the activity result back to the Facebook SDK
        mCallbackManager.onActivityResult(requestCode, resultCode, data);
    }
    // [END on_activity_result]

    // [START auth_with_facebook]
    private void handleFacebookAccessToken(AccessToken token) {
        Log.d(TAG, "handleFacebookAccessToken:" + token);

        AuthCredential credential = FacebookAuthProvider.getCredential(token.getToken());
        mAuth.signInWithCredential(credential)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        if (task.isSuccessful()) {
                            // Sign in success, update UI with the signed-in user's information
                            Log.d(TAG, "signInWithCredential:success");
                            FirebaseUser user = mAuth.getCurrentUser();
                            updateUI(user);
                        } else {
                            // If sign in fails, display a message to the user.
                            Log.w(TAG, "signInWithCredential:failure", task.getException());
                            Toast.makeText(FacebookLoginActivity.this, "Authentication failed.",
                                    Toast.LENGTH_SHORT).show();
                            updateUI(null);
                        }
                    }
                });
    }
    // [END auth_with_facebook]

    private void updateUI(FirebaseUser user) {

    }
}