Cursor stays in the previous after executing with Shift-Enter

[jtpio]

Description

Reproduce

• Open browser tabs
• Type some code in one of them
• Press Shift-Enter
• This automatically creates a new cell below
• See how the cursor stays in the first cell in the other tab

Expected behavior

The cursor should be shown in the second cell.

Context

This was found while looking into jupyter/notebook#6816.

On the screencast above, the browser on the left is Chromium, the one on the right is Firefox.

[krassowski]

Looks related or the same as jupyterlab/jupyterlab#14271

Maybe we are not notifying code mirror correctly about leaving the cell editor?

[davidbrochart]

Maybe I'm not getting the issue, but isn't it the normal behavior that another user cannot move my cursor?
Even if they create a new cell and move their cursor in it, I'm not expecting my cursor to move into this new cell.
Am I missing something?

[krassowski]

maybe collaborator cursors should be visually distinct (beyond colour) to prevent confusion? In 3.x we had a needle pin on collaborator cursors, could we bring this back?

[jtpio]

Maybe I'm not getting the issue, but isn't it the normal behavior that another user cannot move my cursor? Even if they create a new cell and move their cursor in it, I'm not expecting my cursor to move into this new cell. Am I missing something?

The issue here is that the cursor does not follow. See the beginning of screencast:

• left: collaborator executes import this with shift enter and their cursor is on the second cell (expected)
• right: the blue cursor is still in the first cell, the one with import this as the content (unexpected)

[davidbrochart]

Oh I get it now, thanks @krassowski !