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Re: Combobox sufficiently accessibility-supported?

for

From: Bryan Garaventa
Date: Oct 9, 2015 12:06PM

> Certainly for touchscreen/AT users (e.g. mobile phones/tablets), comboboxes can present considerable problems, such as not being able to actually navigate
> to any of the suggestions. This is particularly true for the ones that rely purely on activedescendant, as that - from my cursory testing a while ago -
> is not supported in iOS/VoiceOver nor Android/TalkBack.

This is true, and likely never will be since the element that is touched is the one that is being interfaced with by the AT, and that is what aria-activedescendant will always convey.

It is possible though, to use responsive design to detect touch screen devices and adjust the behavior accordingly so that Listboxes with referenced items aren't lost, and to detect the sizing of such screens to dynamically adjust the number of listed items.

An example of this can be tested at
http://whatsock.com/tsg/Coding%20Arena/ARIA%20Comboboxes/ARIA%20Comboboxes%20(Native%20Inputs,%20Editable%20with%20Substring%20Match)/demo.htm

Which uses the ARIA Combobox module in the TSG at
https://github.com/accdc/tsg

This functionality includes standard desktop navigation usage, but also touch device detection to prevent auto closing when focus moves away from the input, as well as size detection to adjust the list size when viewed on a phone sized device versus a tablet. When typing, a basic live region is used to announce the first suggested item.

I agree that when zooming in for low vision usage, it can be difficult to detect dynamic content such as this when it appears, but from an accessibility standpoint given current technologies and what is possible to accomplish with spec compliant responsive design, it is possible to create dynamic Combobox widgets such as these that are accessible to the vast majority of users if programmed with these concepts in mind.