Improving Tab Navigation

There have been a number of concerns raised with the current 'nav-index' property. This page is to document them and the resulting discussions, with the aim of addressing these issues in a future revision of the UI module.

Extract issues from these and document here as subsections explicitly:

• Visual vs. logical ordering switch
• Handling HTML5's new 0 and -1 behaviors
• Scoping tab navigation indices, so that it can be used in complex pages.

More issues:

• http://lists.w3.org/Archives/Public/wai-xtech/2011Nov/0034.html
• http://lists.w3.org/Archives/Public/wai-xtech/2011Nov/0035.html

HTML has the tabindex attribute (with various levels of browser support) which should be specified there.

Does nav-index belong in HTML or CSS or both?

Current thinking: likely both.

HTML already has tabindex and thus should specify that (see previous).

CSS should specify nav-index because:

• CSS3-UI already specifies directional nav-* properties
• Any style sheet that explicitly specifies the 2 dimensional directional nav-* properties will likely want to also explicitly specify sequential navigation order as well.
• Keeping both sequential and directional nav-* in the same style sheet will help them stay “in sync” across site changes etc.
  • Or rather, having to do them separately in HTML vs CSS will likely cause them to get out of sync.