Problem/Motivation
Some accessibility concerns about the use of sticky table headers were brought up in #3070558: Implement bulk operation designs.
@andrewmacpherson pointed out that the use of a sticky header obscures content. There are two categories of issues this causes:
- In a table such as admin/content users can can navigate to an items hidden beneath a sticky header, so there's no longer a visual indication of the item in focus.
- Speech control users may encounter a problem with "show numbers" functionality, which displays a number label for each control on the page. These labels would also be applied to items concealed by the sticky and cause confusion.
Steps to reproduce
In admin/content, get the page in a position where the header is sticky, then tab-navigate through the table. Note that items hidden underneath the sticky header can still be focused, but the item+focus state is not visible.
Proposed resolution
This issue was discussed with @rain. There was agreement that there are UX benefits to sticky headers (and potentially other sticky elements such as the one proposed in #3070558). While are several straightforward ways to address concern #1 (keyboard users) while retaining the benefits of Sticky navigation, this doesn't seem possible for addressing #2 (Speech control "show numbers"). @rain suggested adding a toggle that allows enabling/disabling of sticky headers. This would allow the subset of users adversely impacted by sticky headers to bypass that functionality.
Remaining tasks
Determine if this is an acceptable change to core
Review the patch
User interface changes
A new toggle button above tables with sticky headers.