didChangeNext method

@override void didChangeNext(Route? nextRoute)

This route's next route has changed to the given new route.

This is called on a route whenever the next route changes for any reason, so long as it is in the history, including when a route is first added to a Navigator (e.g. by Navigator.push), except for cases when didPopNext would be called.

The nextRoute argument will be null if there's no new next route (i.e. if isCurrent is true).

Implementation

@override
void didChangeNext(Route<dynamic>? nextRoute) {
  if (nextRoute is DelegatedTransitionsRoute &&
      nextRoute.canDriveSecondaryTransitionForPreviousRoute(this)) {
    _nextRoutes ??= <DelegatedTransitionsRoute<dynamic>>[];
    _nextRoutes!.add(nextRoute);

    nextRoute.completed.then((dynamic value) {
      _nextRoutes!.remove(nextRoute);
    });
  }
  super.didChangeNext(nextRoute);
}