> ## Documentation Index
> Fetch the complete documentation index at: https://docs.baenninger.me/llms.txt
> Use this file to discover all available pages before exploring further.

# Decorator Pattern

Decorator ist ein strukturelles Entwurfsmuster, mit dem du neue Verhaltensweisen an Objekte anhängen kannst, indem du diese Objekte in speziellen Wrapper-Objekten platzierst, die die Verhaltensweisen enthalten.

## Klassendiagramm

<Frame caption="Structural Patterns">
  <img src="https://mintcdn.com/levexis-38849a2b/Wa_zkryx5Qc1QyS0/images/content/dotnet/class-diagram-6.png?fit=max&auto=format&n=Wa_zkryx5Qc1QyS0&q=85&s=d146c07a6170bac14ae591a3cf2825d5" alt="Abbildung" width="3200" height="2360" data-path="images/content/dotnet/class-diagram-6.png" />
</Frame>

## Implementierung

<Tabs>
  <Tab title="Client">
    ```csharp title="Client.cs" theme={null}
    Component component = new ConcreteDecorator2(
        component: new ConcreteDecorator1(
            component: new ConcreteDecorator1(
                component: new ConcreteComponent())));

    component.Operation();
    ```
  </Tab>

  <Tab title="Component">
    ```csharp title="IComponent.cs" theme={null}
    public interface IComponent
    {
        void Operation();
    }
    ```
  </Tab>

  <Tab title="ConcreteComponent">
    ```csharp title="ConcreteComponent.cs" theme={null}
    public class ConcreteComponent : Component
    {
        public void Operation()
        {
            Console.WriteLine("ConcreteComponent");
        }
    }
    ```
  </Tab>

  <Tab title="Decorator">
    ```csharp title="Decorator.cs" theme={null}
    public abstract class Decorator(Component component) : Component
    {
        protected Component _component = component;

        public virtual void Operation()
        {
            _component.Operation();
        }
    }
    ```
  </Tab>

  <Tab title="ConcreteDecorator1">
    ```csharp title="ConcreteDecorator1.cs" theme={null}
    public abstract class Decorator(Component component) : Component
    {
        protected Component _component = component;

        public virtual void Operation()
        {
            _component.Operation();
        }
    }
    ```
  </Tab>

  <Tab title="ConcreteDecorator2">
    ```csharp title="ConcreteDecorator2.cs" theme={null}
    public class ConcreteDecorator2(Component component) : Decorator(component)
    {
        public override void Operation()
        {
            Console.WriteLine("-------- Concrete Decorator 2 -----------");
            _component.Operation();
            Console.WriteLine("-------- Concrete Decorator 2 -----------");
        }
    }
    ```
  </Tab>
</Tabs>

## Beispiele

### Klassendiagramme

<Frame caption="Structural Patterns">
  <img src="https://mintcdn.com/levexis-38849a2b/Wa_zkryx5Qc1QyS0/images/content/dotnet/class-diagram-7.png?fit=max&auto=format&n=Wa_zkryx5Qc1QyS0&q=85&s=38be3edacea4d07b2868eaa23bd5a17e" alt="Abbildung" width="3568" height="2776" data-path="images/content/dotnet/class-diagram-7.png" />
</Frame>

### Implementierung

<Tabs>
  <Tab title="Client">
    ```csharp theme={null}
    ITeslaModel3 car = new LongRangeTeslaDecorator(
        car: new RedPaintTeslaDecorator(
            car: new BasicTeslaModel3()));

    Console.WriteLine($"Description: {car.GetDescription()}");
    Console.WriteLine($"Price: {car.GetPrice()}");
    Console.WriteLine($"Range: {car.GetRange()}");
    ```
  </Tab>

  <Tab title="Component">
    ```csharp theme={null}
    public interface ITeslaModel3
    {
        decimal GetPrice();
        string GetDescription();
        int GetRange();
    }
    ```
  </Tab>

  <Tab title="ConcreteComponent">
    ```csharp theme={null}
    public class BasicTeslaModel3 : ITeslaModel3
    {
        public string GetDescription()
        {
            return "Tesla Model 3 Rear-Wheel Drive";
        }

        public decimal GetPrice()
        {
            return 38990m;
        }

        public int GetRange()
        {
            return 272;
        }
    }
    ```
  </Tab>

  <Tab title="Decorator">
    ```csharp theme={null}
    public abstract class TeslaDecorator(ITeslaModel3 car) : ITeslaModel3
    {
        protected ITeslaModel3 _car = car;

        public virtual string GetDescription()
        {
            return _car.GetDescription();
        }

        public virtual decimal GetPrice()
        {
            return _car.GetPrice();
        }

        public virtual int GetRange()
        {
            return _car.GetRange();
        }
    }
    ```
  </Tab>

  <Tab title="ConcreteDecorator1">
    ```csharp theme={null}
    public class RedPaintTeslaDecorator(ITeslaModel3 car) : TeslaDecorator(car)
    {
        public override decimal GetPrice()
        {
            return base.GetPrice() + 2000;
        }

        public override string GetDescription()
        {
            return $"{base.GetDescription()}, Red Paint";
        }
    }
    ```
  </Tab>

  <Tab title="ConcreteDecorator2">
    ```csharp theme={null}
    public class LongRangeTeslaDecorator(ITeslaModel3 car) : TeslaDecorator(car)
    {
        public override decimal GetPrice()
        {
            return base.GetPrice() + 3500;
        }

        public override string GetDescription()
        {
            return $"{base.GetDescription()}, Long Range";
        }

        public override int GetRange()
        {
            return base.GetRange() + 91;
        }
    }
    ```
  </Tab>

  <Tab title="ConcreteDecorator3">
    ```csharp theme={null}
    public class BluePaintTeslaDecorator(ITeslaModel3 car) : TeslaDecorator(car)
    {
        public override decimal GetPrice()
        {
            return base.GetPrice() + 1000;
        }

        public override string GetDescription()
        {
            return $"{base.GetDescription()}, Blue Paint";
        }
    }
    ```
  </Tab>
</Tabs>