"Auto-collapse" feature

[RomainWCSBx]

Issue description (New feature)

When going deep in the arborescence, all folders fully expand and therefore turns the tree "unreadable" on the long run

Ideal solution

A toggle button a the right of "File Browser" to collapse the files and folders not belonging to the active path (collapse != hidden)
Untoggle the button will restore the natural visibility of expanded files & folders (WoW as per today)

Alternative

• Untoggle "auto-collapse" just restores current WoW (without restoring folders expansion as before toggle it the first time)
• toggle button to activate / unactivate extension could do the job either (but I'm not sure that it is possible without refreshing the page)

Additional context

• Jupyterlab version: 3.2.9
• Python package version: 3.8.12
• jupyterlab-unfold version: 0.2.2
• Operating System and its version: Debian 11

[krassowski]

I was recently thinking that "collapse all/uncollapse all" would be a good button to have. I am not sure if we should exclude the active path.

Edit: VSCode has it: