[combobox] Combobox inside Popocer input does not focus after Suspense

[OliverJAsh]

Bug report

Current behavior

Open the popover. The input is not focused. It is focused on subsequent opens.

Expected behavior

The input should be focused.

Reproducible example

https://stackblitz.com/edit/evbx5ytg?file=src%2FApp.tsx

Base UI version

1.0.0-beta.5

Which browser are you using?

Chrome

Which OS are you using?

Mac OS

Which assistive tech are you using (if applicable)?

N/A

Additional context

The usage of Combobox without Combobox.Popup inside a Popover is as per this Discord thread: https://discord.com/channels/1287292451308048406/1427370184615788657/1427549259313578035

[atomiks]

This isn't really a bug, you need to manually focus the input after the content loads in. The focus goes on the popover root initially (since there's no tabbable content), and it doesn't decide to change unless you tell it to.

[OliverJAsh]

I’m curious how the input manages to get focus on subsequent opens?

[OliverJAsh]

you need to manually focus the input after the content loads in

If we try to do this then we encounter this issue: #3259

So I'm not sure how we're supposed to solve this? 🤔

I don't think we can use initialFocus because the input is asynchronously loaded.

[atomiks]

You can use requestAnimationFrame for the focus call you mentioned in that issue. A hack, but it reliably waits for the position.

fwiw, el?.focus({preventScroll: true}) would also work, but for some reason Android Chrome still doesn't support it according to MDN 😒

[atomiks]

I think there's a way we can improve this by default so autoFocus works without the scroll issue using a trick with the positioning - I'll look into it.