static void Main(string[] args)
{
Console.WriteLine("***Visitor Pattern Demo***\n");
NumberCollection numberCollection = new NumberCollection();
//Showing the current list
numberCollection.DisplayList();
IncrementNumberVisitor incrVisitor = new IncrementNumberVisitor();
//Visitor is visiting the list
Console.WriteLine("IncrementNumberVisitor is about to visit the list:");
numberCollection.Accept(incrVisitor);
//Showing the current list
numberCollection.DisplayList();
Console.ReadLine();
}
static void Main(string[] args)
{
Console.WriteLine("Visitor Pattern");
#region Visitor pattern - simple
NumberCollection numberCollection = new NumberCollection();
//showing the current list
numberCollection.DisplayList();
IncrementNumberVisitor incrementNumberVisitor = new IncrementNumberVisitor();
//visiting the list
Console.WriteLine("IncrementNumberVisitor is about to visit the list:");
numberCollection.Accept(incrementNumberVisitor);
//showing the current list
numberCollection.DisplayList();
Console.WriteLine();
Console.WriteLine();
#endregion
#region Visitor pattern - composite pattern
#region Mathematics department
//2 lecturers work in Mathematics department
Employee mathTeacher1 = new Employee()
{
Name = "M. Joy",
Dept = "Mathematic",
Designation = "Lecturer",
Experience = 13.7
};
Employee mathTeacher2 = new Employee()
{
Name = "M. Roony",
Dept = "Mathematic",
Designation = "Lecturer",
Experience = 6.5
};
//the college has a Head of Department in Mathematics
CompositeEmployee hodMathematic = new CompositeEmployee()
{
Name = "Mrs. S.Das",
Dept = "Maths",
Designation = "HOD-Maths",
Experience = 14
};
//lecturers of mathematics directly reports to HOD-Maths
hodMathematic.AddEmployee(mathTeacher1);
hodMathematic.AddEmployee(mathTeacher2);
#endregion
#region Computer Science departments
//3 lecturers work in Computer Science department
Employee csTeacher1 = new Employee()
{
Name = "C. Sam",
Dept = "Computer Science",
Designation = "Lecturer",
Experience = 10.2
};
Employee csTeacher2 = new Employee()
{
Name = "C. Jones",
Dept = "Computer Science",
Designation = "Lecturer",
Experience = 13.5
};
Employee csTeacher3 = new Employee()
{
Name = "C. Marium",
Dept = "Computer Science",
Designation = "Lecturer",
Experience = 7.3
};
//the college has a Head of Department in Computer Science
CompositeEmployee hodComputerScience = new CompositeEmployee()
{
Name = "Mr. V.Sarcar",
Dept = "Computer Science",
Designation = "HOD-CS",
Experience = 16.5
};
//lecturers of Computer Science directly report to HOD-CS
hodComputerScience.AddEmployee(csTeacher1);
hodComputerScience.AddEmployee(csTeacher2);
hodComputerScience.AddEmployee(csTeacher3);
#endregion
#region Top level management
//the collage also has a Principal
CompositeEmployee principal = new CompositeEmployee()
{
Name = "Dr. S.Som",
Dept = "Planning-Supervising-Managing",
Designation = "Principal",
Experience = 21
};
//hods of Maths and CS directly report to Principal
principal.AddEmployee(hodMathematic);
principal.AddEmployee(hodComputerScience);
#endregion
//printing the leaf-nodes and branches in the same way
//in each case we are calling DisplayDetails() method
Console.WriteLine("Details of a Principal object is as follows:");
//prints the complete structure
principal.DisplayDetails();
Console.WriteLine("Details of a HOD object is as follows:");
//print details of Computer Science department
hodComputerScience.DisplayDetails();
//leaf node
Console.WriteLine("Details of an individual employee (leaf node) is as follows:");
mathTeacher1.DisplayDetails();
//suppose, one Computer Science lecturer (C. Jones) is leaving now from the organization
hodComputerScience.RemoveEmployee(csTeacher2);
Console.WriteLine("After the resignation of C. Jones, the organization has the following members:");
principal.DisplayDetails();
List <IEmployee> participants = new List <IEmployee>();
//for employees who directly reports to Principal
foreach (IEmployee employee in principal.subordinateList)
{
participants.Add(employee);
}
//for employees who directly reports to HOD-Maths
foreach (IEmployee employee in hodMathematic.subordinateList)
{
participants.Add(employee);
}
//for employees who directly reports to HOD-CS
foreach (IEmployee employee in hodComputerScience.subordinateList)
{
participants.Add(employee);
}
Console.WriteLine("Visitor starts visiting our composite structure.");
VisitorWithCompositePattern.IVisitor visitor = new PromotionCheckerVisitor();
//principal is already holding the highest position
//we are not checking if he is eligible or not
foreach (IEmployee employee in participants)
{
employee.Accept(visitor);
}
#endregion
Console.Read();
}
