import 'package:flutter/material.dart'; class FaderTransition extends PageRouteBuilder { final Widget page; final bool isFast; FaderTransition({required this.page, required this.isFast}) : super( pageBuilder: ( BuildContext context, Animation animation, Animation secondaryAnimation, ) => page, transitionsBuilder: ( BuildContext context, Animation animation, Animation secondaryAnimation, Widget child, ) => FadeTransition( opacity: Tween(begin: 0.0, end: isFast ? 3.0 : 1.0).animate(animation), child: child, ), ); }