Router: this view is about to be permanently destroyed.

Router: take remote focus. Mirrors onScreenShown's focus rule (restore the saved descendant, else focus the view root).

Function called when the screen is being permanently removed by SceneManager Override this to clean up resources: task nodes, observers, large data structures Parent components are responsible for calling onDestroy() on children that need it

Floor for screens that DON'T override onDestroy(): abandon any pending fetchAsync promises so a late pool response can't fire into the destroyed node. Screens that override onDestroy() get this via the auto-abandon-promises BSC plugin (it injects abandonApiPromises() into their own onDestroy) — SG component onDestroy does not chain to this base.

Function called when the screen is hidden by the screen manager It is expected that screens override this function if required, to handle focus any actions required on the screen being hidden

Function called when the screen is displayed by the screen manager It is expected that screens override this function to handle focus managmenet and any other actions required on screen shown

Router: this view has just become active for the first time. Publish it as the active routed view BEFORE onScreenShown so JRScene's overhang controller and main.bs's playback-event observer-attach react to the right node. Screens that need route data read m.top.route (routeParams / queryParams / context) inside their own onScreenShown / onRouteUpdate overrides.

Router: a previously-suspended (keepAlive) view has returned to the top of the stack. Re-publish it as the active routed view, then restore via onScreenShown.

Router: a new view is being pushed on top of this one (still alive). Save focus the same way SceneManager.pushScene does so it can be restored.

Walk the focus chain to the deepest focused descendant and remember it in m.top.lastFocus. Lifted from SceneManager.pushScene's focus-save loop.