Wayland 1.21 Alpha Finally Introduces High-Resolution Scroll Wheel Support

Two years after the merge request was originally opened, the upcoming Wayland 1.21 release is adding high resolution scroll wheel support for mice to match the work carried out for X.Org and within the Linux kernel drivers.

Simon Ser on Thursday announced the release of Wayland 1.21 Alpha. With Wayland itself being relatively stable these days and not too much churn while it's up to the individual Wayland compositors for much of the heavy lifting (or Wayland support libraries like libweston and wlroots), with Wayland 1.21 a notable addition is high resolution scroll wheel support.

High-resolution wheel scrolling is introduced to the wl_pointer protocol via a new "wl_pointer.axis_v120" event for representing wheel detents as fractions or multiples of 120. The "120" approach is to match the behavior seen under Microsoft Windows.

Linux 5.0 and newer have supported high resolution scrolling, permitted it's also supported by the individual hardware driver. Libinput has already supported high resolution scrolling while this work opens it up to Wayland clients. Under X.Org, the xf86-input.libinput driver has already supported this more precise scrolling method. High resolution scrolling also remains open for XWayland, GNOME's Mutter, GTK, and other components.

Beyond the high-resolution wheel scrolling for wl_pointer, Wayland 1.21 Alpha adds various convenience functions and different bug fixes.

More details on Wayland 1.21 Alpha via the Wayland mailing list.