Managed widgets demo for aiogram-dialog

managed.py

from typing import Protocol, TypeVar, Type, Dict, Any

ManagedW = TypeVar("ManagedW", covariant=True)


class Manageable(Protocol[ManagedW]):
    def manage(self) -> ManagedW:
        raise NotImplementedError


class ManagedRadio:
    def print_radio(self) -> None:
        print("manager radio")


class Radio(Manageable[ManagedRadio]):
    def manage(self) -> ManagedRadio:
        return ManagedRadio()


class Manager:
    def __init__(self) -> None:
        self.widgets: Dict[str, Any] = {}

    def find(self, s: str, cls: Type[Manageable[ManagedW]]) -> ManagedW:
        w = self.widgets[s]
        if not isinstance(w, cls):  # error in pycharm
            raise ValueError
        return w.manage()


m = Manager()
m.widgets["r"] = Radio()

r = m.find("r", Radio)
r.print_radio()  # ok


# r.whatever()  # error: "ManagedRadio" has no attribute "whatever"


#####

class ManagedButton:
    def foo(self) -> None:
        pass


class Button:
    def manage(self) -> ManagedButton:
        return ManagedButton()


class ManagedSubButton(ManagedButton):
    def bar(self) -> None:
        pass


class SubButton(Button):
    def manage(self) -> ManagedSubButton:
        return ManagedSubButton()


m.widgets["b"] = Button()
m.widgets["s"] = SubButton()

b = m.find("b", Button)
s = m.find("s", SubButton)
s.foo()  # ok
s.bar()  # ok
s.sss()  # error