w3c / matf

Guidance from the Mobile Accessibility Task Force (MATF)
https://w3c.github.io/matf/
Other
8 stars 3 forks source link

Definition of "dragging movements" in mobile context #65

Open JJdeGroot opened 3 months ago

JJdeGroot commented 3 months ago

In the meeting of 7 August, the definition of dragging movements came up.

WCAG definition of "dragging" covers almost any gesture on mobile because it refers to "down" (i.e. touching screen) and "up" (i.e. lifting finger) events.

  • This seems to apply to anything you do on mobile, this could be too broad to be usable.
  • The Understanding documents is non-normative, only WCAG language is binding.

dragging movements definition

an operation where the pointer engages with an element on the down-event and the element (or a representation of its position) follows the pointer until an up-event

down-event definition

platform event that occurs when the trigger stimulus of a pointer is depressed

The down-event may have different names on different platforms, such as "touchstart" or "mousedown".

up-event definition

platform event that occurs when the trigger stimulus of a pointer is released

The up-event may have different names on different platforms, such as "touchend" or "mouseup".

Understanding 2.5.7 Dragging Movements

When an interface implements functionality that uses dragging movements, users perform four discrete actions:

  1. tap or click to establish a starting point, then
  2. press and hold that contact while...
  3. performing a repositioning of the pointer, before...
  4. releasing the pointer at the end point.

The understanding guidance is more detailed compared to the normative definition of dragging movements.

JJdeGroot commented 3 months ago

Perhaps the "the element (or a representation of its position) follows the pointer" part excludes simple swiping/scrolling gestures? Because the element does not follow the pointer, it's the container element that changes it's scroll position.

cc @jha11y