Update to JupyterLab v3.1 and support RTC

[hbcarlos]

This is a draft PR to update to JupyterLab v3.1 and add support for RTC.

Due to some attributes on the notebook's metadata (kernelspecs and language_info), we don't share the notebook's metadata by default.

TODO:

• Upgrade dependencies to 3.1.
• Use metadata from shared models.
• Check that the metadata from the shared model is saved to disk.
• Check that the nbconvert template works.
• Check that the classic notebook extension works.

Demo:

demo_voila-gridstack_rtc.mp4

[hbcarlos]

This PR is ready. We need to wait for two PRs in JupyterLab:

• Adds shared state
• Save shared metadata

Then we can remove:

voila-gridstack/packages/jupyterlab-gridstack/src/editor/gridstack/model.ts

Lines 83 to 84 in f9d99f3

	// TODO: Remove @ts-ignore
	// @ts-ignore

and

voila-gridstack/.eslintrc.js

Lines 38 to 39 in f9d99f3

	// TODO: Remove ban-ts-comment
	'@typescript-eslint/ban-ts-comment': 'off',

Some of the changes I made:

• Changed the default behavior of items to locked for a better user experience. The user can still move and resize them, but the other items don't move when moving/resizing one item.
• Added a shared attribute executed, used to track if when opening Voila-Gridstack editor another client already executed the cells. Otherwise, every time a client connects, executes all cells.
• Added undo/redo feature.
• Added a warning dialog to advise the user that the compact layout action will only work with unlocked cells.

[jtpio]

Thanks for this!

We need to wait for two PRs in JupyterLab:

Looks like these PRs have now been merged and released. Maybe we can do one more bump to 3.1.9 before merging this one?

[jtpio]

We could also add the jupyterlab-link-share extension to the Binder config, so folks can easily try it out on Binder.

[hbcarlos]

Hey, great to see you are back!

Looks like these PRs have now been merged and released. Maybe we can do one more bump to 3.1.9 before merging this one?

Yes, we need to update to 3.1.9 because the @jupyterlab/testutils v3.1.7 was empty and I had to use the 3.1.6.

I'll do it today.

[jtpio]

Should this be removed now that it has been updated to 3.1.9?

[jtpio]

Following-up on the comment: #142 (comment)

[hbcarlos]

Yes, good catch!

[jtpio]

Thanks, just tested locally and it works great!