Proposed answer for issue #937 (pointer gestures and drag-n-drop)

Hi all,

I have attempted to draft an answer

https://github.com/w3c/wcag21/issues/937#issuecomment-399449006

to the issue I have raised, "Second thoughts on pointer gestures and 
drag-and-drop".

It essentially exempts drag-and-drop interaction from the scope of 
pointer gestures. This is what I have written - compare pull request 
https://github.com/w3c/wcag/pull/379

"The path-based operation used in drag-and-drop interfaces is not 
covered by this success criterion. While drag and drop interaction 
involves a free-form path to move elements to (or within) some drop 
target, it does not use pre-defined gestures in the same way as the 
swiping or dragging of content or controls, or the drawing of specific 
shape patterns. While we encourage authors to create alternatives for 
drag-and-drop interfaces that can be operated with a single pointer 
without path-based gestures, the complexity of providing such 
alternatives is likely to significantly increase interface complexity, 
and is therefore not required by this success criterion."

A paragraph above, I have also qualified "a complex path" by adding 
"matching a pre-defined pattern (such as an L- or Z-shape)" to separate 
it more clearly from freeform paths drawn by users in drag-and-drop 
interactions.

I really don't like this exception, but I think requiring all 
drag-n-drop stuff not only to be keyboard-operable (as the example 
referenced in issue #937) but ALSO have alternative controls for each 
draggable object to move it stepwise in all 4 directions, or have some 
interface for specifying destinations of focused elements, is both 
complex and burdensome, may be hard to get to work well across UAs, adds 
a significant amount of cruft / interface complexity, and is for all 
these reasons very unlikely to be accepted by developers.

So in view of the epic discussion on broad vs. narrow interpretations of 
1.4.11 (I lean towards the narrow view here, too), this is another 
example of narrowing the scope of a new SC to make it more palatable to 
those who make efforts to implement it (and also in recognition of the 
absence of good techniques, author-side or UA-side, to potentially meet 
this SC for drag-and-drop).

I'd be glad if this could go into a survey to put to bed this thorny 
issue (at least for 2.1). All comments welcome, of course!

Detlev





---
Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft.
https://www.avast.com/antivirus