`pyvista` (`pythreejs` or `ipygany` backend) incompatible with `ipywidgets>7.7.2.`

Describe the bug, what’s wrong, and what you expected.

The jupyter backend pythreejs does not work with the newest release if ipywidgets. No plot is produced

Steps to reproduce the bug.

FROM ubuntu:22.04


WORKDIR /tmp/

# pyvista dependencies from apt
RUN apt-get -qq update && \
    apt-get -y install libxrender-dev libgl1-mesa-dev xvfb python3-pip && \
    apt-get clean && \
    rm -rf /var/lib/apt/lists/* /var/tmp/*

# Install python dependencies
RUN pip3 install --upgrade pip 


# Install components from dolfinx/lab
RUN pip3 install pyvista pythreejs ipygany pyvista jupyterlab && \
    pip3 cache purge && \
    jupyter nbextension enable --py --sys-prefix ipygany


EXPOSE 8888/tcp

ENV SHELL /bin/bash
ENTRYPOINT ["jupyter", "lab", "--ip", "0.0.0.0", "--no-browser", "--allow-root"]

import pyvista as pv

sphere = pv.Sphere(center=(1, 0, 0))
cube = pv.Cube()
pv.set_jupyter_backend("pythreejs")
pl = pv.Plotter()
pl.add_mesh(sphere, color='r')
pl.add_mesh(cube, color='b')
pl.show()

Downgrading ipywidgets resolves the issue.

System Information

--------------------------------------------------------------------------------
  Date: Tue Sep 06 11:23:32 2022 UTC

                OS : Linux
            CPU(s) : 8
           Machine : x86_64
      Architecture : 64bit
               RAM : 15.5 GiB
       Environment : Jupyter
       GPU Details : error

  Python 3.10.4 (main, Jun 29 2022, 12:14:53) [GCC 11.2.0]

           pyvista : 0.36.1
               vtk : 9.2.0
             numpy : 1.23.2
           imageio : 2.21.2
           appdirs : 1.4.4
            scooby : 0.5.12
        matplotlib : 3.5.3
           IPython : 8.5.0
        jupyterlab : 3.4.6
         pythreejs : Version unknown
--------------------------------------------------------------------------------

Screenshots

[akaszynski]

Would it be better to raise this in https://github.com/jupyter-widgets/pythreejs? I’m guessing that the issue is actually with pythreejs and not pyvista.

@banesullivan, this really emphasises the need to have a solid jupyter widget from either Kitware or PyVista.

[banesullivan]

I just pushed out ipyvktlink==0.2.3 which pins ipywidgets to ~=7.7 to help mitigate these issues (at least for ipyvtklink)