I am building a custom camera UI from scratches. I would like to implement 2 buttons to swap between normal lens and ultra-wide lens with a smooth effect, like the one is done in the built-in camera of the OS. Right now my 2 buttons call the method _swapCamera, which is implemented like this

  void _swapCamera(CameraDescription camera)  {
    currentCamera = camera;
    _controller.setDescription(camera);
    if (context.mounted) setState(() {});
  }

And the effect is this (ugly black screen)