1670446 - dom.w3c_pointer_events.dispatch_by_pointer_messages breaks scrolling with a pen tablet

Status: RESOLVED DUPLICATE of bug 1637259

(Core :: DOM: UI Events & Focus Handling, defect, P3)

Description

[lolrepeatlol]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:82.0) Gecko/20100101 Firefox/82.0

Steps to reproduce:

I turned on dom.w3c_pointer_events.dispatch_by_pointer_messages in about:config and tried to scroll with my pen tablet by gliding my pen over it (just like thumb scrolling on a phone).

Actual results:

Scrolling stopped working.

Expected results:

The page should have scrolled.

Tested on both Beta 82 and Nightly 83 on Windows 10 2004.

Comment 1

[lolrepeatlol]

To be clear, I turned this flag on to make my pen tablet work in Firefox. I don't know why it didn't work without turning this feature on, as usually tablets work out of the box with dom.w3c_pointer_events.enabled set to true in about:config (should I file a separate bug about that as well?).

The dom.w3c_pointer_events.dispatch_by_pointer_messages flag is usually enabled by people to have pressure sensitivity. If it helps, my tablet is an XP-Pen Star G640S, I believe.

Comment 2

[Edgar Chen [:edgar]]

(In reply to Alexei Solonari from comment #1)

To be clear, I turned this flag on to make my pen tablet work in Firefox. I don't know why it didn't work without turning this feature on, as usually tablets work out of the box with dom.w3c_pointer_events.enabled set to true in about:config (should I file a separate bug about that as well?).

Yeah, please file a separate bug for that. Thanks!

Comment 3

[Edgar Chen [:edgar]]

(In reply to Alexei Solonari from comment #0)

I turned on dom.w3c_pointer_events.dispatch_by_pointer_messages in about:config and tried to scroll with my pen tablet by gliding my pen over it (just like thumb scrolling on a phone).

I think it is because we currently generate mouse events for stylus input when dom.w3c_pointer_events.dispatch_by_pointer_messages set to true, but the scrolling gesture is detected from touch events.

Comment 4

[Kagami Rosylight [:saschanaz] (they/them)]

Let's mark this as a duplicate of bug 1637259, where the fix requires an additional flag dom.w3c_pointer_events.scroll_by_pen.enabled for now.