GNOME Bugzilla – Bug 783716
Support wayland-tablet wheel events
Last modified: 2017-07-20 12:26:42 UTC
Currently it is not possible to scroll within applications using the wheel on a tablet "puck" tool. The necessary codepaths appear to be stubbed out in both Mutter and GTK3. The puck is a somewhat niche tool, but its inability to scroll quickly becomes annoying for those users who have one.
Created attachment 353637 [details] [review] Sample mutter patch
Created attachment 353639 [details] [review] Sample GTK3 patch This sample patch adds scrolling to GTK3, but it seems that not every component actually scrolls in response to the event. Dropdown lists work, but not e.g. text fields... I'm unsure if the issue is with this patch, or elsewhere in GTK.
Comment on attachment 353637 [details] [review] Sample mutter patch The bits in the FIXME were what prevented the feature in the first place. I agree that the heuristic applied is sensible for the time being, and much better than leaving the event not implemented at all.
Comment on attachment 353639 [details] [review] Sample GTK3 patch GDK is responsible for emitting both discrete and smooth scroll events to make the upper layers that use each happy. The patch is missing the latter, which explains the symptoms seen. I will update this patch.
Comment on attachment 353637 [details] [review] Sample mutter patch Pushed attachment 353637 [details] [review] as 4d8cb5408
Created attachment 356026 [details] [review] wayland: Make function to create scroll event more generic Add GdkWaylandPointerData and GdkDevice arguments so it can be used across master devices.
Created attachment 356027 [details] [review] wayland: Implement support for tablet wheel scrolling Adds support for creating scroll events from Wayland tablet wheel events. Even though no Wacom tablet puck has a smooth-scrolling wheel, both event types need to be generated to make the upper layers happy.
Attachment 356026 [details] pushed as e6863da - wayland: Make function to create scroll event more generic Attachment 356027 [details] pushed as 32919a4 - wayland: Implement support for tablet wheel scrolling