Mediator/python/Mediator.py - master - telnov.ob/patterns

Mediator/python/Mediator.py
83 строки2 KB
georgedem
Mediator
11 авг 2022, 21:38
11 авг 2022, 21:38b6264ae
import abc


class IMediator(metaclass=abc.ABCMeta):

    @abc.abstractmethod
    def notify(self, emp: 'Employee', msg: str):
        pass


class Employee(metaclass=abc.ABCMeta):

    def __init__(self, mediator: IMediator):
        self._mediator = mediator

    def set_mediator(self, med: IMediator):
        self._mediator = med


class Designer(Employee):

    def __init__(self, med: IMediator = None):
        super().__init__(med)
        self.__is_working = False

    def execute_work(self):
        print("<-the designer is at work")
        self._mediator.notify(self, "the designer designs...")

    def set_work(self, state: bool):
        self.__is_working = state
        if state:
            print("<-the designer is released from work")
        else:
            print("<-the designer is busy")


class Director(Employee):

    def __init__(self, med: IMediator = None):
        super().__init__(med)
        self.__text: str = None

    def give_command(self, txt: str):
        self.__text = txt
        if txt == "":
            print("->the director knows that the designer is already working")
        else:
            print("->the director gave the command:" + txt)
        self._mediator.notify(self, txt)


class Controller(IMediator):

    def __init__(self, designer: Designer, director: Director):
        self.__designer = designer
        self.__director = director
        designer.set_mediator(self)
        director.set_mediator(self)

    def notify(self, emp: 'Employee', msg: str):
        if isinstance(emp, Director):
            if msg == "":
                self.__designer.set_work(False)
            else:
                self.__designer.set_work(True)

        if isinstance(emp, Designer):
            if msg == "the designer designs...":
                self.__director.give_command("")


if __name__ == '__main__':
    designer = Designer()
    director = Director()

    mediator = Controller(designer, director)

    director.give_command("design")

    print()

    designer.execute_work()