Incompatibility with TransitionsBuilder

[willsmanley]

I would like to do a simple fade transition like this:

navigatorKey.currentState?.pushAndRemoveUntil(
  PageRouteBuilder(
    pageBuilder: (context, animation, secondaryAnimation) => MyWidget(),
    transitionDuration: const Duration(seconds: 2),
    transitionsBuilder: (context, animation, secondaryAnimation, child) {
      return FadeTransition(
        opacity: animation,
        child: child,
      );
    },
  ),
  (Route<dynamic> route) => false,
);

However when I try to implement this with MaterialWithModalsPageRoute, instead of the FadeTransition, there seems to be a permanent right-to-left swipe transition that I can't override, even if I provide my own transitionsBuilder.

[willsmanley]

This is how I tried to implement it with MaterialWithModalsPageRoute:

class FadeModalPageRoute<T> extends MaterialWithModalsPageRoute<T> {
  FadeModalPageRoute({
    required super.builder,
    super.settings,
    super.maintainState,
    super.fullscreenDialog,
  });

  @override
  Widget buildTransitions(BuildContext context, Animation<double> animation,
      Animation<double> secondaryAnimation, Widget child) {
    return FadeTransition(opacity: animation, child: child);
  }
}

but this results in a ghost-y right-to-left transition on top of the fade-in content. basically this is a blocker for using this library since every page needs to be wrapped with this route and every page also needs custom transitions.