/// <summary>
/// # Motivation
/// I can now attach responsibilities to an object dynamically to add behaviour at runtime.
///
/// # Structure
/// Beverage
/// --> base class so all objects are of same type
/// CondimentDecorator : Bevarage
/// --> interchangeable with Beverage
///
/// # Sample Problem
/// A coffee shop wants to make an ordering system for all their drinks. Ofcourse there are a lot of combination with condiments/roasts.
/// We could create a base class and let all possible combinations inherit from the superclass and override their behaviour, but that would quickly become a mess.
///
/// # Solution
/// By creating a Decorator class which inherits from the baseclass (to effectively swap between types), I can now dynamically create composite objects at runtime.
/// To add a drink to the system:
/// 1. inherit from the base class, set instance fields in constructor
/// 2. override the 'Cost()' method to return desired cost
/// To add a condiment to the system:
/// 1. inherit from 'CondimentDecorator' (indirectly from base class as well
/// 2. add instance field from type Beverage
/// 3. initialize in constructor
/// 4. override GetDescription() and Cost() accordingly
/// To create a composite object at runtime:
/// 1. Create a new instance of a drink (Beverage)
/// 2. To add a condiment, assign the instance to a new instance of the condiment with itself as param
/// A. Beverage darkRoast = new DarkRoast();
/// B. darkRoast = new Mocha(darkRoast);
/// </summary>
public void Test()
{
Beverage beverage = new Espresso();
Console.WriteLine($"{beverage.GetDescription()} ${beverage.Cost()}");
Beverage beverage1 = new DarkRoast();
beverage1 = new Mocha(beverage1);
Console.WriteLine($"{beverage1.GetDescription()} ${beverage1.Cost()}");
Beverage beverage2 = new DarkRoast();
beverage2 = new Mocha(beverage2);
Console.WriteLine($"{beverage2.GetDescription()} ${beverage2.Cost()}");
beverage2 = new Mocha(beverage2);
Console.WriteLine($"{beverage2.GetDescription()} ${beverage2.Cost()}");
beverage2 = new Whip(beverage2);
Console.WriteLine($"{beverage2.GetDescription()} ${beverage2.Cost()}");
Beverage beverage3 = new HouseBlend();
beverage3 = new Soy(beverage3);
beverage3 = new Mocha(beverage3);
beverage3 = new Whip(beverage3);
Console.WriteLine($"{beverage3.GetDescription()} ${beverage3.Cost()}");
}
static void Main(string[] args)
{
IBeverage beverage = new DarkRoast();
System.Console.WriteLine($"{beverage.GetDescription()}: ${beverage.GetCost()}\n");
beverage = new Soy(beverage);
System.Console.WriteLine($"{beverage.GetDescription()}: ${beverage.GetCost()}\n");
beverage = new Whip(beverage);
System.Console.WriteLine($"{beverage.GetDescription()}: ${beverage.GetCost()}\n");
beverage = new Mocha(beverage);
System.Console.WriteLine($"{beverage.GetDescription()}: ${beverage.GetCost()}\n");
beverage = new Mocha(beverage);
System.Console.WriteLine($"{beverage.GetDescription()}: ${beverage.GetCost()}\n");
beverage = new Whip(beverage);
System.Console.WriteLine($"{beverage.GetDescription()}: ${beverage.GetCost()}\n");
beverage = new Whip(beverage);
System.Console.WriteLine($"{beverage.GetDescription()}: ${beverage.GetCost()}\n");
beverage = new Whip(beverage);
System.Console.WriteLine($"{beverage.GetDescription()}: ${beverage.GetCost()}\n");
beverage = new Whip(beverage);
System.Console.WriteLine($"{beverage.GetDescription()}: ${beverage.GetCost()}\n");
beverage = new Whip(beverage);
System.Console.WriteLine($"{beverage.GetDescription()}: ${beverage.GetCost()}\n");
beverage = new Whip(beverage);
System.Console.WriteLine($"{beverage.GetDescription()}: ${beverage.GetCost()}\n");
Console.ReadLine();
}
static void Main(string[] args)
{
Beverage beverage = new Espresso();
Console.WriteLine("{0} ${1}", beverage.GetDescription(), beverage.Cost());
beverage.SetSize(3);
Console.WriteLine("{0} ${1}", beverage.GetDescription(), beverage.Cost());
Beverage beverage2 = new Mocha(beverage);
Console.WriteLine("{0} ${1}", beverage2.GetDescription(), beverage2.Cost());
beverage2 = new Mocha(beverage2);
Console.WriteLine("{0} ${1}", beverage2.GetDescription(), beverage2.Cost());
beverage2.SetSize(2);
Console.WriteLine("{0} ${1}", beverage2.GetDescription(), beverage2.Cost());
Console.ReadKey();
}
public void TestExpressoWithSize()
{
BeverageSize beverageSize = BeverageSize.GRANDE;
Beverage beverage = new Expresso();
beverage.Size = beverageSize;
beverage = new Mocha(beverage);
beverage.Size = beverageSize;
Assert.AreEqual("Expresso, Mocha $1.9", beverage.GetDescription() +
" $" + beverage.Cost());
}
public void CanGetDescriptionOfHouseBlendMocha()
{
// Arrange
var mocha = new Mocha(new HouseBlend());
// Act
var description = mocha.GetDescription();
// Assert
Assert.That(description, Is.EqualTo("House Blend, Mocha"));
}
public void HouseBlend_WhenAddDecorators_ValueIsIncreased()
{
Beverage houseBlend = new HouseBlend();
decimal value = houseBlend.Value();
houseBlend = new Soy(houseBlend);
houseBlend = new Mocha(houseBlend);
Assert.NotEqual(value, houseBlend.Value());
Assert.Equal(houseBlend.Description, houseBlend.GetDescription());
}
static void DecoratorInvoke()
{
Beverage beverage = new DarkRoast(); // 焦烤咖啡
Console.WriteLine(beverage.GetDescription() + " $" + beverage.Cost());
beverage = new Mocha(beverage); //添加摩卡
Console.WriteLine(beverage.GetDescription() + " $" + beverage.Cost());
beverage = new Milk(beverage); //添加牛奶
Console.WriteLine(beverage.GetDescription() + " $" + beverage.Cost());
Beverage beverage2 = new Milk(new HouseBlend()); // 家庭混合咖啡加摩卡加牛奶
Console.WriteLine(beverage2.GetDescription() + " $" + beverage2.Cost());
}
static void Main(string[] args)
{
Beverage beverage = new Espresso();
Console.WriteLine($"{beverage.GetDescription()} ${beverage.Cost()}");
Beverage beverage1 = new HouseBlend();
beverage1 = new Soy(beverage1);
beverage1 = new Mocha(beverage1);
beverage1 = new Mocha(beverage1);
Console.WriteLine($"{beverage1.GetDescription()} ${beverage1.Cost()}");
Console.ReadLine();
}
public void Expresso_ShouldBeExpressoAndCostThreeDollarsAndTwentyCents_WhithMochaAndVenti()
{
//Arrange
BeverageSize beverageSize = BeverageSize.VENTI;
Beverage beverage = new Expresso();
beverage.Size = beverageSize;
beverage = new Mocha(beverage);
beverage.Size = beverageSize;
//Act
var description = beverage.GetDescription();
var cost = beverage.Cost();
//Assert
description.Should().Be("Expresso, Mocha");
cost.Should().Be(3.2);
}
static void Decorator()
{
Beverage beverage1 = new Espresso();
Console.WriteLine(beverage1.GetDescription());
Console.WriteLine(beverage1.GetCost());
Beverage beverage2 = new Espresso();
beverage2 = new Mocha(beverage2);
Console.WriteLine(beverage2.GetDescription());
Console.WriteLine(beverage2.GetCost());
Beverage beverage3 = new Espresso();
beverage3 = new Mocha(beverage3);
beverage3 = new Whip(beverage3);
Console.WriteLine(beverage3.GetDescription());
Console.WriteLine(beverage3.GetCost());
}
