[css-display-4] reading-flow/reading-order vs text selection

[fantasai]

Does reading-flow/reading-order affect text selection and caret navigation?

[schenney-chromium]

Test selection seems rather tricky but I can see why it would make sense.

Caret navigation seems like a clear yes, though I would have to check how tab-index plays into that.

[dizhang168]

Wrote this code snippet to test it out. Both the text selection and the caret navigation follow the DOM order on all browsers. AFAIK, neither CSS order nor tabindex affect the text/caret selection.

It would be really tricky to implement this behavior based on reading-flow. It wouldn't be a case of re-ordering the sibling children of a specific container anymore. And how are we meant to interpret the different reading-flow keyword values?

[cookiecrook]

Moved from related FSO issue:

If reading flow affects focus but not selection and caret navigation, there may be a mismatch between types of mixed navigation modes uses by assistive tech users...

• many screen reader users use a combination of navigation mechanisms which don't seem to be accounted for in the focus scope owner proposal
  • linear AT (e.g. next/prev)
  • non-linear AT (e.g. next heading)
  • linear arrow (next/prev char or word)
  • non-liner arrow (e.g. move down a line or page), and
  • tab-based navigation (e.g. next focusable)
• it's not clear to me if focus scope owner would result in a more or less predictable order in a timer-stepped switch interface... For example, some Switch Control users have their step speed set as fast as 50ms (1/20 of a second), so predictability is obviously critical.