ENH: Notebook 3d backend improvements (ipyvtklink)

I open this issue following https://github.com/mne-tools/mne-python/pull/8503#issuecomment-748859979 to keep track of the missing features or anything that could be improved.

Feature status

• Test integration with Google Colab following https://github.com/mne-tools/mne-python/issues/8080#issuecomment-911720213
• HiDPI rendering of 3D and mpl widget (see https://github.com/mne-tools/mne-python/pull/8708#discussion_r561283667)
• Screenshot w/time_viewer is off in the vertical direction (https://github.com/mne-tools/mne-python/pull/8708/files/5d34669c5ea051b1c08dfda19cb1ddf0ba727945#diff-a6e2fc2fab82c1377cb29516fc0a7aed813ee4273daad18cf002e7302a331770)
• Update to ipyvtklink (https://github.com/Kitware/ipyvtklink/pull/30, https://github.com/mne-tools/mne-python/pull/9341)
• Button/shortcut for autoplay (https://github.com/mne-tools/mne-python/pull/8741)
• Button/shortcut to take a screenshot (https://github.com/mne-tools/mne-python/pull/8708)
• Button/shortcut to save a movie (https://github.com/mne-tools/mne-python/pull/9190)
• Button/shortcut to display help (https://github.com/mne-tools/mne-python/pull/9123)
• Label time course mode (https://github.com/mne-tools/mne-python/pull/9016)

Design/UX

• big square button (asked in https://github.com/mne-tools/mne-python/pull/8503#issuecomment-749411804)

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Known issues

Resolved

• Does not play well with Firefox (see https://github.com/mne-tools/mne-python/issues/8704#issuecomment-819447117 and https://github.com/mne-tools/mne-python/issues/8704#issuecomment-819458470)

JupyterLab

• matplotlib is not interactive Javascript Error: IPython is not defined
• The mesh is translucent
• A VTK window opens on local instance

Google Colab

• It is not supported yet (asked in https://github.com/mne-tools/mne-python/pull/8503#issuecomment-751272941, standby in https://github.com/mne-tools/mne-python/issues/8704#issuecomment-756120645)

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A testing notebook is available on gist.github.com.

[agramfort]

this would be a game changer !

Message ID: @.***>

[larsoner]

For movie and autoplay I think you basically need a timer, e.g. https://stackoverflow.com/questions/57255394/jupyter-and-timer-functions

For a screenshot it seems like it should be fairly easy since the ipyvtk_simple is sending bitmaps, and/or we should be able to get the Renderer directly and get the image from it

For label time course do you need more than https://ipywidgets.readthedocs.io/en/latest/examples/Widget List.html#Dropdown ?

For sizing I think it’s https://ipywidgets.readthedocs.io/en/latest/examples/Widget Styling.html