I’ve run into the same issue while porting nautilus to event controllers (still under GTK3, but as preparation for later port to GTK4).
However, GtkEventControllerScroll::scroll
under GTK3 doesn’t have a boolean return value. Therefore, there is no way to conditionally propagate the event.
Would a backport of this to gtk-3-24 be acceptable? eventcontrollerscroll: Conditionally propagate ::scroll (edc4b2f7) · Commits · GNOME / gtk · GitLab
Or, any known workaround while in GTK3?