Flutter - Listening To One Value Through Whole App

Iam using EventChannel to handle events from hardware barcode scanner. EventChannel is initialized in initState, in main class - it works through whole app. While change is detected, it inserts value into global variable (ValueNotifier - i dont know, if it is right) and then I need to work with that value in multiple widgets. I need some sort of widget, which will tell me, that value updated and it will trigger onEvent function - something like RawKeyboardListener. I tried using listeners, but when i do pushNamed, the listener is still listening and it runs code from previous pages, while scanning.

Is there any widget, that would be suitable for me? (cant use ValueListenableBuilder, because it has no "onEvent" function) Or is there any way, to remove and add listeners while moving between pages, or while modal bottom sheet is opened? (I need to access previous listeners, after Navigator.pop)

I solved my problem by using listeners and ModalRoute.of(context).isCurrent.