Next customersshow customersnewhenry velasquez

customers.Next();
customers.Show();
customers.New("Henry Velasquez");
customers.ShowAll();
// Wait for user
Console.Read();
}
}
// "Abstraction"
class CustomersBase
{
private DataObject dataObject;
protected string group;
public CustomersBase( string group)
{
this .group = group;
}
// Property
public DataObject Data
{
set { dataObject = value ; }
get { return dataObject; }
}
public virtual void Next()
{
dataObject.NextRecord();
}
public virtual void Prior()
{
dataObject.PriorRecord();
}
public virtual void New( string name)
{
dataObject.NewRecord(name);
}
public virtual void Delete( string name)
{
dataObject.DeleteRecord(name);
}

An Introduction to Design Patterns
******
For more informations visit
41
public virtual void Show()
{
dataObject.ShowRecord();
}
public virtual void ShowAll()
{
Console.WriteLine("Customer Group: " + group);
dataObject.ShowAllRecords();
}
}
// "RefinedAbstraction"
class Customers : CustomersBase
{
// Constructor
public Customers( string group) : base (group)
{
}
public override void ShowAll()
{
// Add separator lines
Console.WriteLine();
Console.WriteLine ("------------------------");
base .ShowAll();
Console.WriteLine ("------------------------");
}
}
// "Implementor"
abstract class DataObject
{
public abstract void NextRecord();
public abstract void PriorRecord();
public abstract void NewRecord( string name);
public abstract void DeleteRecord( string name);
public abstract void ShowRecord();
public abstract void ShowAllRecords();
}
// "ConcreteImplementor"
class CustomersData : DataObject
{
private ArrayList customers = new ArrayList();
private int current = 0;
public CustomersData()
{
// Loaded from a database
customers.Add("Jim Jones");

An Introduction to Design Patterns
******
For more informations visit
42
customers.Add("Samual Jackson");
customers.Add("Allen Good");
customers.Add("Ann Stills");
customers.Add("Lisa Giolani");
}
public override void NextRecord()
{
if (current <= customers.Count - 1)
{
current++;
}
}
public override void PriorRecord()
{
if (current > 0)
{
current--;
}
}
public override void NewRecord( string name)
{
customers.Add(name);
}
public override void DeleteRecord( string name)
{
customers.Remove(name);
}
public override void ShowRecord()
{
Console.WriteLine(customers[current]);
}
public override void ShowAllRecords()
{
foreach ( string name in customers)
{
Console.WriteLine(" " + name);
}
}
}
}
Output
Jim Jones
Samual Jackson
Allen Good
------------------------
Customer Group: Chicago
Jim Jones

An Introduction to Design Patterns
******
For more informations visit
43
Samual Jackson
Allen Good
Ann Stills
Lisa Giolani
Henry Velasquez
------------------------
4.3 Composite Design Pattern
4.3.1 Definition
Compose objects into tree structures to represent part-whole
hierarchies. Composite lets clients treat individual objects and
compositions of objects uniformly.
4.3.2 UML class diagram
The classes and/or objects participating in this pattern are:
Component (DrawingElement)
Declares the interface for objects in the composition.
Implements default behavior for the interface common to all classes, as appropriate.