Element activation and synthesized events

[chrisosaurus]

This came up when discussing synthesizing an event from AT to represent Activation in #166.

If you have an HTML button with focus then some keypresses (Enter, Space) will synthesize a Click event in addition to the keyboard event.

1. Which elements have activation behaviors triggered by keyboard events ?
   1. What are these keyboard events ?
   2. Where is this specified ?
2. Should this be generalized to support non-built-in elements, and if so, how ?
3. How should this behave for synthesized activation events sent from AT ?

[chrisosaurus]

Some existing elements and their behavior

Element	behavior on Click	behavior on Enter	behavior on Space
<input type=’button’></input>	Click event	Click and Enter events	Click and Space events
<div role=’button’></div>	Click event	Enter event	Space event
<div></div>	Click event	Enter event	Space event
<a href=’...’></a>	Open link	Open link	Space event

[chrisosaurus]

Related links:

Non-click activation behaviours must, by default, fire a Click event.
https://html.spec.whatwg.org/multipage/interaction.html#activation

The activation triggers for <a> elements are Click and Enter.
https://w3c.github.io/uievents/#event-flow-activation

Space and Enter dispatch a Click event when a state-changing element has focus.
https://w3c.github.io/uievents/#event-type-keydown

WHATWG bug “Need a consistent set of events that defines user activation”
whatwg/html#3849