Allow for no selected tab in tabs group

[johannes-becker-otto]

Is your feature request related to a problem? Please describe

My application is starting to have too many tabs. At the same time tabs are nice to switch back and forth. My first approach was to add a menu.
Thanks to v 0.24.0 adding labels to menus this even looks quite smooth.
But now, when I use a link from the menu I get the following situation where the tab marking doesn't match the rest

Describe the solution you'd like

I found old threads about similar discussion (two sets of tabs) and understand that there is no complete solution.
My suggestion would be that if you set for ui.tabs value=None then none of the tabs is highlighted.
This would probably be practical for a few scenarios (e.g. you have a Welcome page that is not part of your tabs).

[mturoci]

Makes sense (although not sure if for your scenario), will be done as part of #1154.

However, as for the UX standpoint, you should always let your users know where they currently are within the navigation hierarchy. This means there should be always exactly 1 active tab at all times.

[johannes-becker-otto]

"This means there should be always exactly 1 active tab at all times."
I agree, the underlying problem is a mix of navigations (part tabs, part menu).
Will have to rethink that part as well...

[mturoci]

If you have too many nav items, maybe it will be better to replace the header with a sidenav which can accommodate more items.

[mturoci]

@marek-mihok please verify if this is resolved with the recent changes for #1154. If yes, close this one.

[marek-mihok]

@mturoci the current implementation (even after #1154) is that you must have 1 tab selected at a time. When the value is set to None, the first tab is being highlighted as a default.

[mturoci]

I see. That's reasonable. Let's close this and reopen in case somebody comes up with a better use case.