Pushandremoveuntil

The “pushAndRemoveUntil” function is a method in Flutter framework, specifically in the Navigation class. It allows you to navigate to a new screen or route, while removing all the previous routes until a specified condition is met. The function signature is as follows:

      Future pushAndRemoveUntil(
        Route newRoute,
        RoutePredicate predicate,
      )
    

The first parameter, “newRoute”, is the route to navigate to. It can be any custom route widget that extends the Flutter’s “Route” class.

The second parameter, “predicate”, is a function that defines the condition for removing the previous routes. It takes a “Route” object as an input and returns a boolean value. If the function returns true, the previous route will be removed. If it returns false, the previous route will not be removed.

Here’s an example usage of the “pushAndRemoveUntil” function:

      Navigator.pushAndRemoveUntil(
        context,
        MaterialPageRoute(builder: (BuildContext context) => NewScreen()),
        ModalRoute.withName('/'),
      );
    

In this example, the current screen will be replaced with the “NewScreen” route, and all previous routes will be removed until the route with the name ‘/’ (root route) is encountered.

This function is particularly useful in scenarios where you want to navigate to a certain screen and remove all the screens in the navigation stack until a specific route is reached. It can be used for authentication flows, onboarding processes, or any situation where you need precise control over the navigation stack.