While implementing persistent bottom bar, previous route need to be restored when a button in the bottom bar was clicked.
When a button in the bottom bar is clicked
Posting this answer mainly for archival purposes, but as @ikben mentioned, one way to get the current route, and all its properties, is ModalRoute.of(context). This returns a ModalRoute, which despite its name, applies to most Navigator.push calls, not just showDialog. Helpful properties include Route.settings, Route.navigator, and Route.isFirst.