Nilearn interactive plotting switching between two images

Hi All,
I just discovered Nipype and Nilearn and really like the integration with Python.
I am searching for interactive plotting in Jupyter notebook, and have used the option nilearn.plotting.view_img. I see that it can display two images in stat_map_img and bg_img and one can use the opacity parameter to change displaying.
What I am searching for is a simple way to toggle between the images. In FSLVIEW one could do this by a simple mouseclick. I need this to check quickly the registration between two images.
So my question is: Is there a way to toggle between front and back image in nilearn.plotting.view_img, or is there a way to use FSLVIEW in interactive mode in Jupyter notebook? Any other tool suggestion for this job is welcome as well. Thank you very much in advance!