private static final int RC_SIGN_IN = 1;
private TextView info;
private LoginButton loginButton;
private CallbackManager callbackManager;

GoogleApiClient mGoogleApiClient;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate (savedInstanceState);
    setContentView (R.layout.activity_main);
    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();
    SignInButton signInButton = (SignInButton) findViewById (R.id.sign_in_button);
    signInButton.setSize (SignInButton.SIZE_STANDARD);
    signInButton.setOnClickListener (new View.OnClickListener () {
        @Override
        public void onClick(View v) {
            signIn ();
        }
    });


    FacebookSdk.sdkInitialize (getApplicationContext ());

    callbackManager = CallbackManager.Factory.create ();
    setContentView (R.layout.activity_main);
    info = (TextView) findViewById (R.id.info);
    loginButton = (LoginButton) findViewById (R.id.login_button);
    loginButton.registerCallback (callbackManager, new FacebookCallback<LoginResult> () {
        @Override
        public void onSuccess(LoginResult loginResult) {
            info.setText (
                    "User ID: "
                            + loginResult.getAccessToken ().getUserId ()
                            + "n" +
                            "Auth Token: "
                            + loginResult.getAccessToken ().getToken ()
            );
        }

        @Override
        public void onCancel() {
            info.setText ("Login attempt canceled.");
        }

        @Override
        public void onError(FacebookException e) {
            info.setText ("Login attempt failed.");
        }
    });

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

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == RC_SIGN_IN) {
        GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
        handleSignInResult(result);
    }
}

private void handleSignInResult(GoogleSignInResult result) {
    if (result.isSuccess()) {
        GoogleSignInAccount acct = result.getSignInAccount();
        Toast.makeText (this,"Name:"+acct.getDisplayName (),Toast.LENGTH_LONG).show ();
        Toast.makeText (this,"Email:"+acct.getEmail (),Toast.LENGTH_LONG).show ();


    } else {
        Toast.makeText (this,"he reject your request",Toast.LENGTH_LONG).show ();
    }
}