using System;
using System.Collections;
namespace DoFactory.GangOfFour.Visitor.RealWorld
{
// MainApp startup application
class MainApp
{
static void Main()
{
// Setup employee collection
Employees e = new Employees();
e.Attach(new Clerk());
e.Attach(new Director());
e.Attach(new President());
// Employees are 'visited'
e.Accept(new IncomeVisitor());
e.Accept(new VacationVisitor());
// Wait for user
Console.Read();
}
}
// "Visitor"
interface IVisitor
{
void Visit(Element element);
}
// "ConcreteVisitor1"
class IncomeVisitor : IVisitor
{
public void Visit(Element element)
{
Employee employee = element as Employee;
// Provide 10% pay raise
employee.Income *= 1.10;
Console.WriteLine("{0} {1}'s new income: {2:C}",
employee.GetType().Name, employee.Name,
employee.Income);
}
}
// "ConcreteVisitor2"
class VacationVisitor : IVisitor
{
public void Visit(Element element)
{
Employee employee = element as Employee;
// Provide 3 extra vacation days
Console.WriteLine("{0} {1}'s new vacation days: {2}",
employee.GetType().Name, employee.Name,
employee.VacationDays);
}
}
class Clerk : Employee
{
// Constructor
public Clerk() : base("Hank", 25000.0, 14)
{
}
}
class Director : Employee
{
// Constructor
public Director() : base("Elly", 35000.0, 16)
{
}
}
class President : Employee
{
// Constructor
public President() : base("Dick", 45000.0, 21)
{
}
}
// "Element"
abstract class Element
{
public abstract void Accept(IVisitor visitor);
}
// "ConcreteElement"
class Employee : Element
{
string name;
double income;
int vacationDays;
// Constructor
public Employee(string name, double income,
int vacationDays)
{
this.name = name;
this.income = income;
this.vacationDays = vacationDays;
}
// Properties
public string Name
{
get{ return name; }
set{ name = value; }
}
public double Income
{
get{ return income; }
set{ income = value; }
}
public int VacationDays
{
get{ return vacationDays; }
set{ vacationDays = value; }
}
public override void Accept(IVisitor visitor)
{
visitor.Visit(this);
}
}
// "ObjectStructure"
class Employees
{
private ArrayList employees = new ArrayList();
public void Attach(Employee employee)
{
employees.Add(employee);
}
public void Detach(Employee employee)
{
employees.Remove(employee);
}
public void Accept(IVisitor visitor)
{
foreach (Employee e in employees)
{
e.Accept(visitor);
}
Console.WriteLine();
}
}
}
