Smart WPF Login Overlay (Windows 8 Style)

//	--------------------------------------------------------------------
//		Member of the WPFSmartLibrary
//		For more information see : http://wpfsmartlibrary.codeplex.com/
//		(by DotNetMastermind)
//
//		filename		: PasswordBoxBinding.cs
//		namespace	: SoftArcs.WPFSmartLibrary.UIClassAttachedProperties
//		class(es)	: PasswordBoxBinding
//							
//	--------------------------------------------------------------------
using System;
using System.Security;
using System.Windows;
using System.Windows.Controls;

namespace SoftArcs.WPFSmartLibrary.UIClassAttachedProperties
{
	public class PasswordBoxBinding
	{
		#region Fields

		private static bool IsUpdating;

		#endregion

		#region DependencyProperty - Password ("string")

		public static string GetPassword(DependencyObject dpo)
		{
			return (string)dpo.GetValue( PasswordProperty );
		}
		public static void SetPassword(DependencyObject dpo, string value)
		{
			dpo.SetValue( PasswordProperty, value );
		}
		/// <summary>
		/// Gets or sets the bindable Password property on the PasswordBox control. This is a dependency property.
		/// </summary>
		public static readonly DependencyProperty PasswordProperty =
					DependencyProperty.RegisterAttached( "Password", typeof( string ),
																	 typeof( PasswordBoxBinding ),
																	 new FrameworkPropertyMetadata( String.Empty,
																	 new PropertyChangedCallback( OnPasswordPropertyChanged ) ) );
		/// <summary>
		/// Handles changes to the 'Password' attached property.
		/// </summary>
		private static void OnPasswordPropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
		{
			PasswordBox targetPasswordBox = sender as PasswordBox;

			if (targetPasswordBox != null)
			{
				targetPasswordBox.PasswordChanged -= PasswordBox_PasswordChanged;

				if (IsUpdating == false)
				{
					targetPasswordBox.Password = (string)e.NewValue;
				}

				targetPasswordBox.PasswordChanged += PasswordBox_PasswordChanged;
			}
		}

		/// <summary>
		/// Handle the 'PasswordChanged'-event on the PasswordBox
		/// </summary>
		private static void PasswordBox_PasswordChanged(object sender, RoutedEventArgs e)
		{
			PasswordBox passwordBox = sender as PasswordBox;

			IsUpdating = true;
			SetPassword( passwordBox, passwordBox.Password );
			IsUpdating = false;
		}

		#endregion
	}
}