Make appearance of toc in sidebar context aware

[t-makaro]

The "cell tools" tab on the left sidebar only appears when a jupyter notebook is open. It would be nice if this extension did something similar.

Especially once jlab enables undocking of sidebar tabs. It'd personally move toc to the right sidebar (yes jlab does have a right sidebar already), and have all of the tabs that are dependant on open files on the right.

[ian-r-rose]

Hi @t-makaro, there is currently work ongoing in JupyterLab for both reducing the space that the side area tabs take up, and docking them on the left/right areas as the user desires.

I am a little reticent to have the TOC appear/disappear depending on whether a document it understands is active. I think the sudden disappearance and reappearance of the "Cell Tools" tab is kind of busy and confusing. Do you think the reduced crowding from the above changes would be a good enough way to address the problem?

[t-makaro]

I personally think that the user should have the option to set a sidebar tab visibility to true, false or auto. The cell tools tab doesn't make sense to have if a user is never (or rarely) working with notebooks. I don't think it's unusual for programs to be adaptive in this manner. (Like how in MS word, certain tabs on the ribbon only appear if you're clicked on a table or a image, which is fairly similar to only having cell tools available with notebooks. Though maybe ToC doesn't fit this manner as well)

Personally, I'd move tabs that are document dependent to the right side bar and leave the main ones on the left side bar. This way the right side bar adapts, but the left is constant. Granted a tab disappearing while is it open would be weird. I think having tabs available that aren't relevant to any open documents can also be confusing to a user. (People may feel like "why isn't this working?" or "what does this ever do?" especially new users)

All that said, being able to move stuff to the right side would go most of the way to making me happy. Though (hopefully) ToC wouldn't have to make adaptive appearance the default behaviour. I suppose that adaptive sidebar tabs is something that needs more discussion in general.