We have this note at the top of section 9:
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").
We discussed the PR a bit on Twitter. I think there should be normative text that REQUIRES that touch-action apply to a device if and only if InputDeviceCapabilities.pointerMovementScrolls is true.
In particular, I think doing anything else would cause a web compat and interop problem. Eg. if we decided to change ChromeOS so that pen dragging scrolled but DIDN'T honor touch-action, then tons of sites like Google Maps would be broken when you drag with pen (since you'd get a pointercancel).
The simplest way to do that is to probably refactor the text at the top of 10.3 into a section that defines the term "direct manipulation pointing device", and then reference that term from both the touch-action and implicit capture sections.
@patrickhlauke @mustaqahmed @NavidZ WDYT?
We have this note at the top of section 9:
We discussed the PR a bit on Twitter. I think there should be normative text that REQUIRES that touch-action apply to a device if and only if InputDeviceCapabilities.pointerMovementScrolls is true.
In particular, I think doing anything else would cause a web compat and interop problem. Eg. if we decided to change ChromeOS so that pen dragging scrolled but DIDN'T honor touch-action, then tons of sites like Google Maps would be broken when you drag with pen (since you'd get a pointercancel).
The simplest way to do that is to probably refactor the text at the top of 10.3 into a section that defines the term "direct manipulation pointing device", and then reference that term from both the touch-action and implicit capture sections.
@patrickhlauke @mustaqahmed @NavidZ WDYT?