How to check which the current Route is?

Question

I want to navigate to different Routes using a Drawer, though I do not want to open a new instance of a Route each time I tap on it if I am already on that Route, rather I would

Answer 1

Rémi's answer really helped me, but if you're new to Flutter/Dart like me, it takes a while to understand. So here's a my version with some extra checks and explanatory documentations:

/// Navigates through the application. Only replaces the top Route if it is
/// different from the new Route. Always keeps the home page as base of the
/// Navigator stack. New screens are pushed on the Navigator stack. When the
/// user switches between non-home screens, the new screen replaces the old
/// screen. In this way, the stack of screens from the drawer is never higher
/// than 2. Returning to the HomeScreen is done by just popping the current
/// Route.
void _changeRoute(BuildContext context, String newRouteName) {
  // Close drawer
  Navigator.pop(context);

  // Check current screen status
  bool currentRouteIsHome = false;
  bool currentRouteIsNewRoute = false;

  Navigator.popUntil(context, (currentRoute) {
    // This is just a way to access currentRoute; the top route in the 
    // Navigator stack.
    if (currentRoute.settings.name == HomeScreen.ROUTE_NAME) {
      currentRouteIsHome = true;
    }
    if (currentRoute.settings.name == newRouteName) {
      currentRouteIsNewRoute = true;
    }

    // Return true so popUntil() pops nothing.
    return true;
  });

  // Switch screen
  if (!currentRouteIsNewRoute) {
    // Only switch screen if new route is different from current route.
    if (currentRouteIsHome) {
      // Navigate from home to non-home screen.
      Navigator.pushNamed(context, newRouteName);
    } else {
      if (newRouteName == HomeScreen.ROUTE_NAME) {
        // Navigate from non-home screen to home.
        Navigator.pop(context);
      } else {
        // Navigate from non-home screen to non-home screen.
        Navigator.popAndPushNamed(context, newRouteName);
      }
    }
  }
}

Note that this implementation with pushNamed and popAndPushNamed requires you to define Route names in your top level MaterialApp in the routes: argument, like so:

new MaterialApp(
  routes: {
    // define the routes
    YOUR_SCREEN_ROUTE_NAME: (BuildContext context) => new YourScreen(),
  },
)