Flutter stream doesn't listen or detect change

Question

I have problem, i have 3 dart files,

home.dart contain button with onclick:

final cartEmiter = CartEmitter();
cartEmiter.emitCart("add_cart");

cart.dart contain:

class CartEmitter {
  StreamController _controller = StreamController.broadcast();
  void emitCart(action) {
    _controller.add(action);
    // print(action);
  }

  Stream get cartAction => _controller.stream;
}

and in main.dart I have this code to change the cart badge.

StreamSubscription _cartCountSubscribtion;

int _cartCount = 0;

@override
  void initState() {
    _cartCountSubscribtion = CartEmitter().cartAction.listen((action) {
      print(action);
      setState(() {
         _cartCount++;
      });
    });
    super.initState();
  }

  @override
  void dispose() {
    _cartCountSubscribtion.cancel();
    super.dispose();
  }

But it doesn't work, no error, no output printed. Is my code wrong or how to listen to change?