Trap screen reader focus

[steveszc]

Currently focus-trapper only traps keyboard and mouse focus, but it may not actually trap focus for some screen readers. Some research is needed to figure out the best way to trap screen reader focus.

Some ideas to explore:

• html's new inert attribute
• make everything else in the DOM aria-hidden="true"
• make everything else in the dom tab-index=-1
• ... other ideas??

[MelSumner]

There are some useful ideas here: https://bitsofco.de/accessible-modal-dialog/ and here: https://www.w3.org/TR/2017/NOTE-wai-aria-practices-1.1-20171214/examples/dialog-modal/dialog.html

👍

[MelSumner]

@steveszc looking at this issue again- there are different types of focus, visible focus and screen-reader focus (for browse mode). We definitely should never try to control screen-reader focus. I have a writeup about it but we can chat more on Discord if you would find it useful.