[css-anchor-position] position-try-options interaction with position-visibility

[kbrilla]

When exploring chrome blog describing https://developer.chrome.com/blog/anchor-positioning-api?hl=en i encountered that there is no support for using position-visibility with position-try-options or at least it does not work as one would expect.

For example:

  position-visibility: no-overflow;
  position-try-options: flip-block;

as I scroll I would expect
first flip to happen as soon as overflow would kick in then as overflow would kick in again for tooltip to be hidden.
so:


And now it should be hidden but stay visible

https://codepen.io/krzbri/pen/OJYymRv

and now

  position-visibility: no-overflow;
  position-try-options: flip-block;

here I would expect basically the same same behaviour with the exception that now we are talking about visibility of anchor.
What happens though is that as soon as top anchor is hidden it does not try to first try to use bottom anchor as position-try-options: flip-block; would suggest.

So here I would except to first switch to bottom anchor and only when this one is hidden for tooltip to be hidden.

https://codepen.io/krzbri/pen/jOobmmd

I found one similar issue but it seemd difrent enauch to open this one but linking it just in case: #10201

[fantasai]

@kbrilla I think this is already what the spec requires? Maybe would be useful to add a WPT testcase, but if I'm understanding the request correctly I think we don't need any spec edits.

The idea of no-overflow is that

1. We try positioning on top, when that overflows
2. Try positioning on the bottom, but
3. If both options would overflow, hide the item

Lmk if that matches, or if you're asking for something different.