Restore tab highlighting

[LiveTrower]

closes #112323

This PR returns the tab highlighting, but in a more understated fashion compared to the original theme, ensuring the aesthetic aligns with the new theme.

Before	After

Classic	Modern

Note: This PR has already solved the issue of poor tab visibility, but this PR can still be relevant purely as an aesthetic change. If the majority of people are already satisfied with the current appearance of the modern theme, we can close this.

[DeeJayLSP]

As much as I like having a highlight on tabs, it simply doesn't fit well with rounded corners.

[shakesoda]

helps a lot

[DeanLemans]

my opinion changed, i no longer see enough need for this change

old comment:
This is way better for readability

[DeeJayLSP]

I'd like to take a moment to suggest something...

---

Like I mentioned, the round corners make bringing back the top highlight... ugly. But it would look less ugly if left and right borders are also highlighted IMO.

I would advise caution when copypasting colors from the classic theme, to avoid stuff like #112443

[TheESN]

I'd like to take a moment to suggest something...

Like I mentioned, the round corners make bringing back the top highlight... ugly. But it would look less ugly if left and right borders are also highlighted IMO.

I would advise caution when copypasting colors from the classic theme, to avoid stuff like #112443

Can you show how these tabs look on full screenshots please?

[akien-mga]

I'm neutral on this, but I agree that the rounded corners make the thin highlight a bit weird. It should also be tested with various DPI scales (on HiDPI it should be 2px tall).

Another idea if a highlight is really needed would be to underline the tab name with the accent color. Either the actual text if we can do that, or the whole tab (so introducing a line between the tab and its container).
Just quick thoughts, I haven't mocked it up to see if it would look good.

[passivestar]

This is a matter of preference, but personally I agree that the line doesn't work as well on rounded tabs compared to the old rectangular ones. That's probably the reason it's rare to see rounded tabs with a top accent in UI nowadays.

Also note that unlike some apps that use an extra tab accent for app-wide focus indication and have only one accented tab at a time on screen, godot draws it per tabbar which makes the UI look busier.

[groud]

I think the thin line does not look great, and indeed, I agree with @passivestar that, in general, those line do not work well with rounded UIs.

Also, I would like to point out that it does not bring a lot, UX-wise, to add that highlight there. It drags the attention too much on a thing that does not really need more attention IMO. If the contrast is still too low, I guess it could be increased again. Yet adding a accent color there is unneeded I think.

I suspect many like this proposal because it looks aesthetically pleasing to add a bit more accent color. So while I don't think adding it to the tabs would work well with the new theme, there may be other places where we could do some touch-ups and add colors back. I would like it, but that's just a personal preference, and I am not sure about how and where it could be implemented.

[DeeJayLSP]

Two alternatives in practice (both with a 2px line):

Surrounding line	Under line

Both bring the highlight back without looking ugly due to round borders.

If we did any change, I think I would agree with the under line, as it's neither ugly due to clashing with round corners, nor draws too much attention like the surrounding line.

[groud]

I think the first one still looks bad. And for the underline, the problem is that is creates a logical border between the tab name and its content. It really makes it look like two separated blocks, which is not great I believe.

[Mickeon]

There's so much differing opinions on this highlight. Professionally, it doesn't belong in the new theme. Casually, some users genuinely like the highlight by sheer virtue of existing.

I would heavily suggest opening a proposal as a result, and potentially gather more community feedback in other ways.

[DeanLemans]

i mean, we do have a new modern theme right? isnt the point breaking existing norms/"compatibility"?

users can just switch back to the classic theme.

an alternative would be to make tab highlighting an option in the theme settings

[LiveTrower]

I'm going to be honest, I no longer care about this change; I had made it because of issue #112323. If anyone else would like to make a proposal, because I no longer find good arguments to defend this. Currently, there are more serious problems in the modern theme than this.