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Re: Applying 2.5.1 Pointer Gestures to tile sliders in native apps.

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From: Steve Green
Date: Apr 14, 2023 10:57AM

I don't have a problem with the WCAG definition of a path-based gesture. A swipe gesture does not just rely on the two end points. Although the gesture does not have to go through any specific points, it must not do certain things, otherwise it will not be recognised. For instance, if you traced a wiggly line from left to right it may not be recognised as a swipe even if it has the exact same end points are a straight swipe.

Also, devices don't respond to correct gestures if they are made too slowly, or sometimes if they are made too fast. For instance, when using Voiceover on iOS, I always have difficulty with actions that require swiping up from the bottom of the screen at specific speeds.

Steve Green
Managing Director
Test Partners Ltd


-----Original Message-----
From: WebAIM-Forum < <EMAIL REMOVED> > On Behalf Of glen walker
Sent: Friday, April 14, 2023 5:38 PM
To: WebAIM Discussion List < <EMAIL REMOVED> >
Subject: Re: [WebAIM] Applying 2.5.1 Pointer Gestures to tile sliders in native apps.

It's interesting that the understanding document says, "A path-based gesture involves an interaction where not just the endpoints matter. If going through an intermediate point also affects its meaning then it is a path-based gesture." So a path-based gesture requires at least 3 points and not just the endpoints.

If you think about swiping or sliding a carousel type widget, there aren't three points involved in that process so it shouldn't be considered path-based, based on that definition. In fact, sliding a carousel only cares about the starting point and then which direction from that starting point you start dragging. The actual end point of that process is somewhat irrelevant so it doesn't really have two points in the path.

But then the understanding document says, "Examples of path-based gestures include swiping, sliders and carousels dependent on the direction of interaction".

That seems contradictory. They define path-based to have 3 (or more) points in the path but then give an example of something that doesn't even have 2 points.

If the carousel had next/previous buttons at either end, in addition to supporting swiping, then you wouldn't have a problem. But without those buttons, does it fail 2.5.1? Based on the definition in the understanding section, I don't think it does. Of course, the understanding section is not normative and it's unfortunate that the definition of "path-based" is not a link in the actual guideline because that would have made the definition normative.