- From: Patrick H. Lauke via GitHub <sysbot+gh@w3.org>
- Date: Wed, 31 Mar 2021 14:01:45 +0000
- To: public-pointer-events@w3.org
A few more thoughts to discuss: at the start of [9. Declaring candidate regions for default touch behaviors](https://w3c.github.io/pointerevents/#declaring-candidate-regions-for-default-touch-behaviors), it reads: ``` <p>For touch input, the default action of any and all pointer events MUST NOT be a manipulation of the viewport (e.g. panning or zooming).</p> ``` followed by the note: ``` Touch manipulations are intentionally not a default action of pointer events. Removing this dependency on the cancellation of events facilitates performance optimizations by the user agent. ``` It's unclear to me, as a reader, what this actually means/refers to. What concept is this trying to convey? I'm guessing it's essentially saying here that panning/zooming is special and not counted as a "default action" in the sense of [5.1.3.1 Attributes and Default Actions](https://w3c.github.io/pointerevents/#attributes-and-default-actions), and that for this reason panning/zooming also can't be cancelled by cancelling/preventing the event. This may need a bit more clarification/expansion. Perhaps even foreshadowing what we say later about `pointercancel` being fired. And then leading into the actual reason for this whole section: "instead, authors can control how user agents should handle panning/zooming using the `touch-action` CSS property instead". That first sentence (about "default action ... MUST NOT be a manipulation of the viewport...") then seems at odds with the first note in [9.1 The touch-action CSS property](https://w3c.github.io/pointerevents/#the-touch-action-css-property) ``` As noted previously, in the case of user agents that allow default behaviors (such as panning or zooming) for other pointer types... ``` In that note, I think we need to drop the mention of "default behaviors" since we just said previously that panning/zooming isn't counted as a default behavior. --- Now also wondering about the second note at the start of the whole [9. Declaring candidate regions for default touch behaviors](https://w3c.github.io/pointerevents/#declaring-candidate-regions-for-default-touch-behaviors) section ``` While the issue of pointers used to manipulate the viewport is generally limited to touch input (where a user's finger can both interact with content and pan/zoom the page), certain user agents may also allow the same types of (direct or indirect) manipulation for other pointer types. For instance, on mobile/tablet devices, users may also be able to pan using a stylus. This section applies to these scenarios as well (despite the specification's use of "touch"). ``` Should we make this normative and more prominent somehow (not sure if we have a style/semantic for it...like a warning boxout that doesn't make it informative only), and if that's sufficient to then simply forego #350 -- GitHub Notification of comment by patrickhlauke Please view or discuss this issue at https://github.com/w3c/pointerevents/pull/349#issuecomment-811092269 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Wednesday, 31 March 2021 14:01:47 UTC