ReadonlyactiveReadonlyactiveReadonlygroupsReadonlyonReadonlyonReadonlyoptionsReadonlyrootThe outermost dockview element (the shell, which also contains edge groups). A getter — it must resolve to the shell once that exists, not the inner gridview, or keydowns from edge groups are missed.
The next / previous group in gridview (spatial) order, wrapping round — the one piece of navigation that needs the grid internals. All other focus logic lives in the service, using the public group API.
The nearest grid group in a spatial direction — drives Alt+Arrow nav.
Fires before / after a structural layout change — used to restore focus on close.