[css-overflow-5] Bikeshed pseudoclasses for active scroll-marker #10918
Description
Currently the css-overflow-5 draft spec allows using :checked to style the active scroll marker.
See flackr/carousel#28 for previous discussion on this.
On the semantics, a marker can be implicitly (through scrolling to that area) or explicitly (clicked on) activated. In either case, it remains active as long as the active marker calculation determines it to be so. As such, this should not be related to focus or direct interaction which go away when the user starts using other controls.
Options:
- Continue using
:checked. The HTML and css-selectors spec say that checked represents a selected-ness. Scroll markers can be selected by the user explicitly or implicitly by scrolling, and cannot be independently checked as they cannot be radio buttons, checkboxes or select options so the use cases when checkedness applies shouldn't overlap. - Use
:currentas suggested in Consider using:current(+:past&:future) instead of:checkedfor markers flackr/carousel#28 (comment). As @tabatkins points out, this already has a meaning independent of markers which means both sets of meanings could apply making this potentially confusing. - Use
:active. This has the right sound to it, but:activealready has a meaning which should separately apply to a scroll-marker when it is being interacted with. - Something else?