Prevent black band running down the screen?

问题

Logging in using [this] package causing the following behaviour. I think the darkening of the screen is expected but it's the ungraceful departure that is the problem..

I don't get an error..but this appears on the console.

W/ActivityThread(31387): handleWindowVisibility: no activity for token android.os.BinderProxy@a1edd0f

My code is the recommended code for the plugin.

void loginWithGoogle() async {
    var auth = AuthProvider.of(context).auth;

    print('Signing up with google...');
    setState(() {
      _showProgressIndicator = true;
    });
    FirebaseUser user = await auth.signInWithGoogleAcc();
    uId = user.uid;

    if (uId != null) {
      print('Signed in: $uId');
      widget.onSignedIn(user);
    } else {
      print('google login cancelled...');
    }

    setState(() {
      _showProgressIndicator = false;
    });
  }

This is happening on an android device.

来源：https://stackoverflow.com/questions/54945622/prevent-black-band-running-down-the-screen