VoiceOver have some bug with role dialog and aria-modal true attribute

• Component: Accessibility
• Status: NEW ---

[Hyongsop Kim]

Developers use aria-modal true and role dialog in layer popup with overlay screen.
Otherwise VoiceOver users cannot distinguish which part is the visible screen, because dimmed contents that is hidden from screen can be focusable with VoiceOver.
However even if add role dialog with aria-modal true, VoiceOver can be navigated some outside contents.
In case of aria spec, if I use aria-modal true, screen reader just can be navigated inside the aria-modal contents.
I think this is the VoiceOver or webkit bug.
Below is the sample site that you can test.
You can doubletap activate modal button with demo 1.
After that, swipe left or right to navigate contents.
You can navigate return repository link.
However this link is the outside content of modal dialog.
and Below is the demonstration video.
You can watch and it will be helpful to understand the issue.
Sample link: http://davidtheclark.github.io/react-aria-modal/demo/
Demonstration video: https://1drv.ms/v/s!Aj9xs5XCa0zwmMMAH2hJMM8MTM4OIg?e=m2aybK

[Radar WebKit Bug Importer]

<rdar://problem/76205537>