Abstract Factory - Creational Design Pattern

Here our specification for any Windowing Kit ends. Now each Windowing Kit Provider can make his/her own Windowing Kit by implementing these three interfaces in his/her own specific ways. Like one may provide Windowing Kit with rectangular buttons while other providing the kit with rounded buttons with images on face and etc. The most important part of this all is that our Windowing System will handle each kit in the same way using these interface reference as we will show soon.

Now, let we make a standard (or default) windowing kit. First we need to implement WindowingKit interface as

// Concrete Factory1 - Standard (Default) Kit
class StandardKit : WindowingKit
{
public Window CreateWindow()
{
return new StandardWindow();
}
public Button CreateButton()
{
return new StandardButton();
}
}

Note that CreateWindow() method of StandardKit is returning a new instance of StandardWindow which is its own defined class that implements the Window interface as

// Concrete Product1 Of Factory1
class StandardWindow : Window
{
private string title="MyStandard Window";
public void Draw()
{
Console.WriteLine("Drawing Standard Window: {0}...", title);
}
public void Minimize()
{
Console.WriteLine("Minimizing Standard Window: {0}...", title);
}
public string Title
{
get { return title; }
set
{
title = "MyStandard Window - " + value;
Draw();
}
}
}

The same is true for CreateButton() Method of StandardKit. Also, in the similar way, another vendor has given her Windowing Kit implementation naming it ExternalKit. (See Source Code for this)

Finally in the Main method, our Windowing System uses each of the two Windowing Kits (StandardKit, ExternalKit) one by one to create and use their specific controls (products). The code for main method is like

static void Main(string[] args)
{
WindowingKit standard = new StandardKit(); // creating StandardKit Factory
WindowingKit external = new ExternalKit(); // creating ExternalKit Factory
ArrayList winKits = new ArrayList(); // collecting the kits
winKits.Add(standard);
winKits.Add(external);
foreach(WindowingKit winKit in winKits) // using each kit
{
Window win = winKit.CreateWindow(); // Make a Window of this kit
win.Draw(); // Perform different operations
win.Minimize();
win.Title = "Notepad";
Console.WriteLine();
Button btn = winKit.CreateButton(); // Make a Button of this kit
btn.Draw(); // Perform different operations
btn.Text = "Submit";
Console.WriteLine();
}
}