Intent
The intent of this Success Criterion is to ensure that Assistive Technologies (AT)
can gather information about, activate(or set) and keep up to date on the status of
user interface controls in the content.
When standard controls from accessible technologies are used, this process is straightforward.
If the user interface elements are used according to specification the conditions
of this provision will be met. (See examples of Success Criterion 4.1.2 below)
If custom controls are created, however, or interface elements are programmed (in
code or script) to have a different role and/or function than usual, then additional
measures need to be taken to ensure that the controls provide important information
to assistive technologies and allow themselves to be controlled by assistive technologies.
A particularly important state of a user interface control is whether or not it has
focus. The focus state of a control can be programmatically determined, and notifications
about change of focus are sent to [...]