
The overview has it's own workspace scroll handling, and we don't want to switch workspaces in other modes. Limiting the scroll-event handler to NORMAL mode matches the swipe tracker used by WorkspaceAnimation, and allows for other uses of scroll events (like scrolling in the alt-tab popup). https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/3840 Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1746>