LoginActivity.java

package org.gdgsrilanka.io;

import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.Toast;

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


import com.crashlytics.android.Crashlytics;
import com.facebook.AccessToken;
import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;

import com.facebook.login.Login;
import com.facebook.login.LoginManager;
import com.facebook.login.LoginResult;
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.api.GoogleApiClient;
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.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.auth.GoogleAuthProvider;
import com.twitter.sdk.android.core.Callback;
import com.twitter.sdk.android.core.Result;
import com.twitter.sdk.android.core.TwitterException;
import com.twitter.sdk.android.core.TwitterSession;
import com.twitter.sdk.android.core.identity.TwitterLoginButton;

import io.fabric.sdk.android.Fabric;
import java.util.Arrays;

public class LoginActivity extends AppCompatActivity {

    public static final String TAG = "MainActivity";
    public static final int RequestSignInCode = 7;
    private static final int RequestSignInCodeTwitter = 10;
    public FirebaseAuth firebaseAuth;
    public GoogleApiClient googleApiClient;
    com.google.android.gms.common.SignInButton signInButton;
    ImageView bg;
    private TwitterLoginButton mTwitterLoginButton;
    private RelativeLayout mRelativeLayout;
    private CallbackManager mCallbackManager;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Fabric.with(this, new Crashlytics());
        setContentView(R.layout.activity_login);

        FacebookSdk.sdkInitialize(getApplicationContext());
        AppEventsLogger.activateApp(this);

        mRelativeLayout = (RelativeLayout) findViewById(R.id.relative_layout_main);

        signInButton = findViewById(R.id.sign_in_button);
        signInButton = findViewById(R.id.sign_in_button);

        mTwitterLoginButton = (TwitterLoginButton) findViewById(R.id.login_button_twitter);

        firebaseAuth = FirebaseAuth.getInstance();


        FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
        if (user != null) {
            Intent homedir = new Intent(LoginActivity.this,HomeActivity.class);
            startActivity(homedir);
            finish();
        }

        mCallbackManager = CallbackManager.Factory.create();

        LoginManager.getInstance().registerCallback(mCallbackManager,
                new FacebookCallback<LoginResult>() {
                    @Override
                    public void onSuccess(LoginResult loginResult) {
                        startActivity(new Intent(LoginActivity.this, HomeActivity.class));
                    }

                    @Override
                    public void onCancel() {
                        Snackbar.make(mRelativeLayout, getString(R.string.fb_login_fail_message), Snackbar.LENGTH_SHORT).show();
                    }

                    @Override
                    public void onError(FacebookException exception) {
                        Snackbar.make(mRelativeLayout, getString(R.string.login_fail_message), Snackbar.LENGTH_SHORT).show();
                    }
                });

        GoogleSignInOptions googleSignInOptions = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestIdToken(getString(R.string.default_web_client_id))
                .requestEmail()
                .build();

        googleApiClient = new GoogleApiClient.Builder(LoginActivity.this)
                .enableAutoManage(LoginActivity.this , new GoogleApiClient.OnConnectionFailedListener() {
                    @Override
                    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

                    }
                } /* OnConnectionFailedListener */)
                .addApi(Auth.GOOGLE_SIGN_IN_API, googleSignInOptions)
                .build();

        signInButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                UserSignInMethod();
            }
        });

        mTwitterLoginButton.setCallback(new Callback<TwitterSession>() {
            @Override
            public void success(Result<TwitterSession> result) {
                startActivity(new Intent(LoginActivity.this, HomeActivity.class));
            }

            @Override
            public void failure(TwitterException exception) {
                Snackbar.make(mRelativeLayout, getString(R.string.login_fail_message), Snackbar.LENGTH_SHORT).show();
            }
        });

    }

    public void UserSignInMethod(){
        Intent AuthIntent = Auth.GoogleSignInApi.getSignInIntent(googleApiClient);
        startActivityForResult(AuthIntent, RequestSignInCode);
    }




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

        if (requestCode == RequestSignInCode){

            GoogleSignInResult googleSignInResult = Auth.GoogleSignInApi.getSignInResultFromIntent(data);

            if (googleSignInResult.isSuccess()){

                GoogleSignInAccount googleSignInAccount = googleSignInResult.getSignInAccount();

                FirebaseUserAuth(googleSignInAccount);
            }

        }

        if (resultCode == RequestSignInCodeTwitter){
            mTwitterLoginButton.onActivityResult(requestCode, resultCode, data);
        }
    }


    AccessToken accessToken = AccessToken.getCurrentAccessToken();
    boolean isLoggedIn = accessToken != null && !accessToken.isExpired();



    public void FirebaseUserAuth(GoogleSignInAccount googleSignInAccount) {

        AuthCredential authCredential = GoogleAuthProvider.getCredential(googleSignInAccount.getIdToken(), null);

        firebaseAuth.signInWithCredential(authCredential)
                .addOnCompleteListener(LoginActivity.this, new OnCompleteListener() {
                    @Override
                    public void onComplete(@NonNull Task AuthResultTask) {

                        if (AuthResultTask.isSuccessful()){

                            Intent homedir = new Intent(LoginActivity.this,HomeActivity.class);
                            startActivity(homedir);

                            finish();

                        }else {
                            Toast.makeText(LoginActivity.this,getString(R.string.firebase_login_error),Toast.LENGTH_LONG).show();
                        }
                    }
                });
    }

}