Broadcast data to multiple widgets in Flutter
Navigator.push returns a Future that will complete when Navigator.pop is called (and this can optionally be used to pass data back to the widget that called push). So for example suppose your login button has this onPressed handler:
onPressed: () async { bool isLoggedIn = await Navigator.pushNamed(context, '/login'); if (isLoggedIn) { // do something }}When your login page calls Navigator.pop(true), the Future will complete with a value of true which will be assigned to the isLoggedIn variable. (You'll get null if the user uses the back button to return to the previous screen.)
This is how showDialog works as well.