class Client
{
void Main()
{
var structure = new ObjectStructure();
structure.Add(new ElementA());
structure.Add(new ElementB());
structure.Accept(new ConcreteVisitor1());
structure.Accept(new ConcreteVisitor2());
}
}
abstract class Visitor
{
public abstract void VisitElementA(ElementA elemA);
public abstract void VisitElementB(ElementB elemB);
}
class ConcreteVisitor1 : Visitor
{
public override void VisitElementA(ElementA elementA)
{
elementA.OperationA();
}
public override void VisitElementB(ElementB elementB)
{
elementB.OperationB();
}
}
class ConcreteVisitor2 : Visitor
{
public override void VisitElementA(ElementA elementA)
{
elementA.OperationA();
}
public override void VisitElementB(ElementB elementB)
{
elementB.OperationB();
}
}
class ObjectStructure
{
List<Element> elements = new List<Element>();
public void Add(Element element)
{
elements.Add(element);
}
public void Remove(Element element)
{
elements.Remove(element);
}
public void Accept(Visitor visitor)
{
foreach (Element element in elements)
element.Accept(visitor);
}
}
abstract class Element
{
public abstract void Accept(Visitor visitor);
public string SomeState { get; set; }
}
class ElementA : Element
{
public override void Accept(Visitor visitor)
{
visitor.VisitElementA(this);
}
public void OperationA()
{ }
}
class ElementB : Element
{
public override void Accept(Visitor visitor)
{
visitor.VisitElementB(this);
}
public void OperationB()
{ }
}