Is there another way than using patterns to manage state ? (Flutter)

I have been developping a small "days left before an event" Flutter app for myself.

The main page consists of a list of "Events" widgets and infos about them. Main page

On the right side of any "Event" there is a bin icon that simply sends an SQL query to delete the event from the DB on tap.

Unfortunately I have been encountering troubles refreshing the main page after the tap on the bin icon because I have no reference of the state of the main page in the "Event" widget.

I have resolved the problem by creating a refresh function in my main page state :

void refresh() {
  setState(() {});
}

and sending a reference --> "var hp" of the state of my main page to the "Event" widget:

class Event extends StatefulWidget {
  String title;
  DateTime date;
  int id;
  String daysLeft;
  Color daysColor;
  var hp;

Event(this.hp, this.title, this.date, this.daysLeft, this.daysColor,
      [this.id]) {
    if (this.title == null) {
      this.title = "No title";
    }
  }
...

thus, I can refresh my main page when tapping on the bin icon :

GestureDetector(
                onTap: () {
                  db.deleteEvent(widget.id);
                  log("refreshing page inc...");
                  widget.hp.refresh();
                  log("refreshed");
                },
                child: Container(
                    margin: EdgeInsets.only(right: 15),
                    child: Icon(
                      Icons.delete,
                      size: 30,
                    )))

I am aware that this looks super ugly. Moreover, the state of the main page being a private class, I had to store it in a "var" which I do not like.

Is there any other way to do that kind of things ? This all looks super complicated and not really smooth to implement.

I have done some researches and it seems there are a few state management patterns (https://flutter.dev/docs/development/data-and-backend/state-mgmt/options?fbclid=IwAR2yiPjh_jPQKb9s3-2nBYRQwbQmhyv_6tjnZTqbpRbdJOZJdyDFy9HZ07E)

But is there no other way than implementing pattern to do this ?

Thanks :)