Improve open tab navigation at 400% browser zoom

[isabela-pf]

Please note that I am writing about JupyterLab main document area tabs like files and consoles, not tab key navigation.

Context

In reviewing zoom and reflow status of JupyterLab, @steff456 noted some ways that JupyterLab tabs begin to be less functional as they get larger. In a meeting, I proposed two ways we might want to add to JupyterLab tabs, but found in further review some equivalent of these behaviors already exist in JupyterLab.

Current state

#9 has a review of the current state. Basically

• There is less room for tabs as JupyterLab gets larger with browser zoom. (And tabs may even disappear if “simple mode” is initiated.)
• There is less room for other UI that may help the user navigate open tabs.
• The Tabs menu has a list of open tabs, albeit at the bottom of the menu.
• The Running tab in the left side bar switches to the selected open tab if clicked on, though there is no indication that this area is a button or that it would do this when activated.

Accessibility considerations

There are a few accessibility considerations that may be helpful to keep in mind if we want to evaluate the current state and proposed solutions. We may want to check for

• How these features work with only a keyboard
• How these features might need to be labeled (visually, as proper HTML, or as additional metadata)
• If these features are available in the command palette
• If there is a tool tip on related buttons and if it is adequately descriptive
• If these need to be more discoverable, reordered, or alternatively accessed when zoomed in
• If keyboard focus is actually activated and moved to the relevant tab in the main document area when these features are used (or is it only a visual change)
• Something else that you think of

Proposed solutions

Depending on answers to the above section, I could imagine a few smaller improvements ensuring this experience is well-rounded and better serving of 400% browser zoom views.

I think the matter of having the tab list be closer to the actual tabs could also be up for further discussion. While the other options exist, I do think there is a chance people could go to the standard tabs are first when looking for their tabs (I am biased, however).

Please let me know if you have any questions.

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cc @kulsoomzahra

[trallard]

@gabalafou @isabela-pf has this been completed or do we need to keep this open?

[trallard]

Superseded by jupyterlab/lumino#297 - might need to follow up with Mike on the status and if we can help to move this forward.

[trallard]

@steff456 to follow up on the lumino PR w/Mike

[trallard]

@steff456 did you manage to sync with Mike on this?

[steff456]

I messaged him yesterday, so I'm waiting for his reply

UPDATE: He was doing the PR in his free time and doesn't have the bandwidth to finish it soon