initialRoute: 'Home',
onGenerateRoute: (RouteSettings routeSettings){
    return new PageRouteBuilder<dynamic>(
      settings: routeSettings,
      pageBuilder: (BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
        switch (routeSettings.name){
          case 'Home':
            return HomePage();
          case 'Other':
            return OtherPage();
          default:
            return null;
        }
      },
      transitionDuration: const Duration(milliseconds: 300),
      transitionsBuilder: (BuildContext context, Animation<double> animation,
          Animation<double> secondaryAnimation, Widget child) {
          return effectMap[PageTransitionType.slideInLeft](Curves.linear, animation, secondaryAnimation, child);
      }
    );
}

// use Navigator
Navigator.of(context).pushNamed('Other');
// or
Navigator.of(context).push(PageTransition(type: PageTransitionType.slideInLeft, child: FirstPage()));

transitionEffect.createCustomEffect(
  handle: (Curve curve, Animation<double> animation, Animation<double> secondaryAnimation, Widget child) {
    return new SlideTransition(
      position: new Tween<Offset>(
        begin: const Offset(1.0, 0.0),
        end: const Offset(0.0, 0.0),
      ).animate(CurvedAnimation(parent: animation, curve: curve)),
      child: child,
    );
  }
);

// use custom
effectMap[PageTransitionType.custom](Curves.linear, animation, secondaryAnimation, child);