Neos-ui: Remember open tab when hiding Inspector

[ComiR]

Description

When I close the inspector and reopen it again, I want to see the same tab as before.

Steps to Reproduce

1. Select other tab than first in inspector
2. Close inspector
3. Reopen inspector

Expected behavior

The same tab is selected/open.

Actual behavior

Affected Versions

Neos: 3.3.9
UI: 1.0.9

[maltemuth]

I think it's this line: https://github.com/neos/neos-ui/blob/3a0f314bc593aae3e8668468936f75e63c232d45/packages/neos-ui/src/Containers/RightSideBar/index.js#L68

When the RightSideBar gets toggled, all child components are destroyed and lose their state, unless it is stored somewhere else. The Tabs component (part of @neos-project/react-ui-components) does not store the active panel on the outside and defaults to the first tab on recreation.

I'm very new to reading React & Redux code - is my analysis right? If so, I think changes need to be made to the Tabs component (so it can "leak" the active tab index somehow) as well as the redux store to store it.

Alternatively (though that might be a can of worms) the RightSideBar could be hidden using CSS only.

I'd like to take a stab at a PR, if someone could check that this is the right direction.

[dimaip]

@maltemuth you are precisely correct. In fact it was originally hidden via CSS, but I changed not to render hidden stuff, as a performance optimization.
I'll think what to do about it.

[ComiR]

It would also be nice to remember the opened tab when switching pages. I.e. I had to change a few document types and always was starting on the first tab after changing the page, which was kind of annoying.
Keep that in mind when thinking about another way to implement ;)

Thanks already!

[Sebobo]

I also recently realized that it would make a lot of sense if the tabs wouldn't remember the tab number when I switch between elements, but the identifier of the tab. This way I could show an analysis in the inspector which updates when switching content. Right now I can't guarantee that not suddenly a different tab is visible.

[Sebobo]

I made the PR for the remembering the tab by identifier instead of the index. So any change here might need to build on that. See #2383