Facebook and Google Login using a custom button in an android studio.

Creating New Project

• Create a new project in Android Studio from File ⇒ New Project. When selecting Empty Activity and proceed.
• Add Facebook and Google dependency to your build.gradle and rebuild the project.

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    //noinspection GradleCompatible
    implementation 'com.android.support:appcompat-v7:27.1.1'
    implementation 'com.android.support:design:27.+'
    implementation 'com.android.support.constraint:constraint-layout:1.1.0'
    implementation 'com.android.support:support-v4:27.1.1'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    implementation 'com.facebook.android:facebook-android-sdk:[4,5)'
    implementation 'com.google.android.gms:play-services:12.0.1'
}

•  Open String.xml located under res ⇒ values and add the below values.

<resources>
    <string name="app_name">GoogleFbLoginstring>
    <string name="facebook_app_id">303427880192019string>
    <string name="fb_login_protocol_scheme">fb303427880192019string>
resources>

Create four XML layouts named activity_main.xml  under res ⇒ layouts.

xml version="1.0" encoding="utf-8"?>
<ScrollView 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=".LoginActivity">
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingTop="56dp"
        android:paddingLeft="24dp"
        android:paddingRight="24dp">
        <FrameLayout
            android:id="@+id/FrameLayout1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" >
            <com.facebook.login.widget.LoginButton
                android:id="@+id/login_button"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:visibility="gone" />
            <Button
                android:id="@+id/fb"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:background="#416BC1"
                android:onClick="onClick"
                android:text="FaceBook Login"
                android:textColor="#ffffff"
                android:textStyle="bold" />
        FrameLayout>
        <FrameLayout
            android:id="@+id/FrameLayout2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp">
            <com.google.android.gms.common.SignInButton
                android:id="@+id/btn_sign_in"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="0dp" />
            <Button
                android:id="@+id/google"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:background="#cf4333"
                android:onClick="onClick"
                android:text="Google Login"
                android:textColor="#ffffff"
                android:textStyle="bold" />
        FrameLayout>
    LinearLayout>
ScrollView>

• Open MainActivity.java and modify the code as below. 

package com.wapptech.waytofeed;

import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

import com.bumptech.glide.Glide;
import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;
import com.facebook.GraphRequest;
import com.facebook.GraphResponse;
import com.facebook.login.LoginResult;
import com.facebook.login.widget.LoginButton;
import com.google.android.gms.auth.api.Auth;
import com.google.android.gms.auth.api.signin.GoogleSignInAccount;
import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
import com.google.android.gms.auth.api.signin.GoogleSignInResult;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.SignInButton;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.OptionalPendingResult;
import com.google.android.gms.common.api.ResultCallback;
import com.google.android.gms.common.api.Status;

import org.json.JSONException;
import org.json.JSONObject;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.Arrays;
import java.util.List;

import static android.provider.ContactsContract.Intents.Insert.EMAIL;

public class MainActivity extends AppCompatActivity implements View.OnClickListener, GoogleApiClient.OnConnectionFailedListener{
    private static final String TAG = MainActivity.class.getSimpleName();
    private static final int RC_SIGN_IN = 430;
    private GoogleApiClient mGoogleApiClient;
    private SignInButton btnSignIn;
    public LoginButton loginButton;
    public Button fb, google;
    public CallbackManager callbackManager;
    public String id, name, email, gender, birthday;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        callbackManager = CallbackManager.Factory.create();
        fb = (Button) findViewById(R.id.fb);
        google = (Button) findViewById(R.id.google);
        loginButton = (LoginButton) findViewById(R.id.login_button);
        List < String > permissionNeeds = Arrays.asList("user_photos", "email",
                "user_birthday", "public_profile", "AccessToken");
        loginButton.registerCallback(callbackManager, new FacebookCallback < LoginResult > () {@Override
        public void onSuccess(LoginResult loginResult) {
            System.out.println("onSuccess");
            String accessToken = loginResult.getAccessToken()
                    .getToken();
            Log.i("accessToken", accessToken);
           GraphRequest request = GraphRequest.newMeRequest(
                    loginResult.getAccessToken(),
                    new GraphRequest.GraphJSONObjectCallback() {@Override
                    public void onCompleted(JSONObject object,
                                            GraphResponse response) {
                        Log.i("LoginActivity",
                                response.toString());
                        try {
                            id = object.getString("id");
                            try {
                                URL profile_pic = new URL(
                                        "http://graph.facebook.com/" + id + "/picture?type=large");
                                Log.i("profile_pic",
                                        profile_pic + "");

                            } catch (MalformedURLException e) {
                                e.printStackTrace();
                            }
                            Log.e("UserDate", String.valueOf(object));
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                    });
            Bundle parameters = new Bundle();
            parameters.putString("fields","id,name,email,gender, birthday");
            request.setParameters(parameters);
            request.executeAsync();
        }
            @Override
            public void onCancel() {
                System.out.println("onCancel");
            }
            @Override
            public void onError(FacebookException exception) {
                System.out.println("onError");
                Log.v("LoginActivity", exception.getCause().toString());
            }
        });
        initializeControls();
        initializeGPlusSettings();
    }
    private void initializeControls(){
        btnSignIn = (SignInButton) findViewById(R.id.btn_sign_in);
        btnSignIn.setOnClickListener(this);
    }
    private void initializeGPlusSettings(){
        GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestEmail()
                .build();
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .enableAutoManage(this, this)
                .addApi(Auth.GOOGLE_SIGN_IN_API, gso)
                .build();
        btnSignIn.setSize(SignInButton.SIZE_STANDARD);
        btnSignIn.setScopes(gso.getScopeArray());
    }

    private void signIn() {
        Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient);
        startActivityForResult(signInIntent, RC_SIGN_IN);
    }

    private void signOut() {
        Auth.GoogleSignInApi.signOut(mGoogleApiClient).setResultCallback(
                new ResultCallback() {
                    @Override
                    public void onResult(Status status) {
                        updateUI(false);
                    }
                });
    }


    private void handleGPlusSignInResult(GoogleSignInResult result) {
        Log.d(TAG, "handleSignInResult:" + result.isSuccess());
        if (result.isSuccess()) {
            GoogleSignInAccount acct = result.getSignInAccount();
            //Fetch values
            String personName = acct.getDisplayName();
            String personPhotoUrl = acct.getPhotoUrl().toString();
            String email = acct.getEmail();
            String familyName = acct.getFamilyName();
            Log.e(TAG, "Name: " + personName +", email: " + email + ", Image: " + personPhotoUrl +", Family Name: " + familyName);
            updateUI(true);
        } else {
            updateUI(false);
        }
    }
    @Override
    public void onStart() {
        super.onStart();

        OptionalPendingResult opr = Auth.GoogleSignInApi.silentSignIn(mGoogleApiClient);
        if (opr.isDone()) {
            Log.d(TAG, "Got cached sign-in");
            GoogleSignInResult result = opr.get();
            handleGPlusSignInResult(result);
        } else {
            opr.setResultCallback(new ResultCallback() {
                @Override
                public void onResult(GoogleSignInResult googleSignInResult) {
                    handleGPlusSignInResult(googleSignInResult);
                }
            });
        }
    }
    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
        // An unresolvable error has occurred and Google APIs (including Sign-In) will not
        // be available.
        Log.d(TAG, "onConnectionFailed:" + connectionResult);
    }
    @Override
    protected void onActivityResult(int requestCode, int responseCode,
                                    Intent data) {
        if (requestCode == RC_SIGN_IN) {
            GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
            handleGPlusSignInResult(result);
        }else{
            super.onActivityResult(requestCode, responseCode, data);
            callbackManager.onActivityResult(requestCode, responseCode, data);
        }
    }
    public void onClick(View v) {
        if (v == fb) {
            loginButton.performClick();
        }else if(v == google){
            signIn();
        }
    }
    private void updateUI(boolean isSignedIn) {
        if (isSignedIn) {
            btnSignIn.setVisibility(View.GONE);
        } else {
            btnSignIn.setVisibility(View.VISIBLE);
        }
    }

}

• After Finally open AndroidManifest.XML and make MainActivity as launcher activity. 

xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.wapptech.menu">

    

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">

    <meta-data android:name="com.facebook.sdk.ApplicationId"
        android:value="@string/facebook_app_id"/>

    <activity android:name="com.facebook.FacebookActivity"
        android:configChanges=
            "keyboard|keyboardHidden|screenLayout|screenSize|orientation"
        android:label="@string/app_name" />
    <activity
        android:name="com.facebook.CustomTabActivity"
        android:exported="true">
        <intent-filter>
            <action android:name="android.intent.action.VIEW" />
            <category android:name="android.intent.category.DEFAULT" />
            <category android:name="android.intent.category.BROWSABLE" />
            <data android:scheme="@string/fb_login_protocol_scheme" />
        intent-filter>
    activity>

        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            intent-filter>
        activity>
    application>

manifest>

Github Link: https://github.com/Sudarshan101/GoogleFbLoginCustom