patterns/abstract_factory.dart

abstract class Drinkable {
  void pour();
}

class Lemonade implements Drinkable { 
  void pour() {
    print("Пью холодный лемонад!");
  }
}

class Coffee implements Drinkable {
  void pour() {
    print("Пью горячий шоклад!");
  }
}

abstract class DrinkFactory {
  Drinkable createDrink();
  DrinkFactory();
}

class Cafe implements DrinkFactory {
  Drinkable createDrink() {
    return Lemonade();
  }
}

class CoffeeShop implements DrinkFactory {
  Drinkable createDrink() {
    return Coffee();
  }
}

void main() {
  var temperature = "cold";
  late DrinkFactory destination;

  switch (temperature) {
    case "cold":
      destination = CoffeeShop();
      break;
    case "warm":
      destination = Cafe();
      break;
    default:
      print("Мне ни холодно, ни жарко...");
  }

  var drinkable = destination.createDrink();
  drinkable.pour();

  /*
     Пью горячий шоклад!
  */
}