Google+ sign out from a different activity

Question

I have started using the Google+ API for android, and I have created a sign-in application following this tutorial:

https://developers.google.com/+/mobi

Answer 1

You can get instance of FirebaseAuth anywhere from the app as FirebaseAuth is a singleton class.

 mAuth = FirebaseAuth.getInstance();
 mAuth.signOut();

Answer 2

Here's my solution. I have made a Utils singleton class. In my LoginActivity, I have a GoogleSignInClient object. So just before starting the DashboardActivity after login, I save the instance of googleSignInClient object by calling Utils.getInstance().setGoogleSignInClient(googleSignInClient). Now anywhere else, if I want to logout I have this method in Utils ready:

public void signOut() {
    googleSignInClient.signOut();
    FirebaseAuth.getInstance().signOut();
}

So now, I can do this from any other activity:

else if (id == R.id.action_logout) {
    Utils.getInstance().signOut();
    Intent intent = new Intent(this, LoginActivity.class);
    startActivity(intent);
}

Yes, you need to log out from both of them, otherwise, you might not see the account chooser the next time you tap the login button.

Answer 3

sommesh's answer is perfect, but for less code you can use "Public Static Method" like this:

public static GoogleApiClient mGoogleApiClient;
...
...
public static void signOutFromGoogle() {
    Auth.GoogleSignInApi.signOut(mGoogleApiClient).setResultCallback(
            new ResultCallback<Status>() {
                @Override
                public void onResult(Status status) {
                    //...
                }
            });
}

And on your other Activity call it:

Your_Google_Activity.mGoogleApiClient.connect();
btnSignOut.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {            
        Your_Google_Activity.signOutFromGoogle();
    }
});