WPF Control Factory

using System;
using System.Reflection;
using System.Windows.Controls;
using Pfz.DataTypes;

namespace Pfz.WpfControls
{
	/// <summary>
	/// Control that shows a string representation of many types, such as
	/// integers, short-integers, decimals and others. Of course, string
	/// itself is valid.
	/// </summary>
	public class StringControl:
		UserControl,
		IValueControl,
		IHasPreferredDataType,
		IValueContainer<string>,
		IValueContainer<long>,
		IValueContainer<long?>,
		IValueContainer<int>,
		IValueContainer<int?>,
		IValueContainer<short>,
		IValueContainer<short?>,
		IValueContainer<byte>,
		IValueContainer<byte?>,
		IValueContainer<sbyte>,
		IValueContainer<sbyte?>,
		IValueContainer<decimal>,
		IValueContainer<decimal?>,
		IValueContainer<EmailString>
	{
		private TextBox fTextBox = new TextBox();
		
		/// <summary>
		/// Creates a new StringControl instance.
		/// </summary>
		public StringControl()
		{
			Content = fTextBox;
		}
		
		/// <summary>
		/// Clears the internal textbox.
		/// </summary>
		public void Clear()
		{
			fTextBox.Clear();
		}
		
		/// <summary>
		/// Gets or sets a value indicating if this control is read-only.
		/// </summary>
		public bool IsReadOnly
		{
			get
			{
				return fTextBox.IsReadOnly;
			}
			set
			{
				fTextBox.IsReadOnly = value;
			}
		}
	
		/// <summary>
		/// Gets or sets the value as a simple string.
		/// </summary>
		public string Value
		{
			get
			{
				string text = fTextBox.Text;
				if (text.Length == 0)
					return null;
					
				return text;
			}
			set
			{
				fTextBox.Text = value;
			}
		}
		
		#region IValueContainer Members
			object IValueContainer.Value
			{
				get
				{
					var preferredProperty = fPreferredValueProperty;
					if (preferredProperty == null)
						return Value;
					
					return fPreferredValueProperty.GetValue(this, null);
				}
				set
				{
					if (value == null)
						Clear();
					else
						fTextBox.Text = value.ToString();
				}
			}
		#endregion

		#region IValueContainer<long> Members
			long IValueContainer<long>.Value
			{
				get
				{
					return Convert.ToInt64(Value);
				}
				set
				{
					Value = value.ToString();
				}
			}
		#endregion
		#region IValueContainer<long?> Members
			long? IValueContainer<long?>.Value
			{
				get
				{
					string value = Value;
					if (string.IsNullOrEmpty(value))
						return null;
					
					return Convert.ToInt64(value);
				}
				set
				{
					if (value.HasValue)
						Value = value.Value.ToString();
					else
						Clear();
				}
			}
		#endregion
		#region IValueContainer<int> Members
			int IValueContainer<int>.Value
			{
				get
				{
					return Convert.ToInt32(Value);
				}
				set
				{
					Value = value.ToString();
				}
			}
		#endregion
		#region IValueContainer<int?> Members
			int? IValueContainer<int?>.Value
			{
				get
				{
					string value = Value;
					if (string.IsNullOrEmpty(value))
						return null;
					
					return Convert.ToInt32(value);
				}
				set
				{
					if (value.HasValue)
						Value = value.Value.ToString();
					else
						Clear();
				}
			}
		#endregion
		#region IValueContainer<short> Members
			short IValueContainer<short>.Value
			{
				get
				{
					return Convert.ToInt16(Value);
				}
				set
				{
					Value = value.ToString();
				}
			}
		#endregion
		#region IValueContainer<short?> Members
			short? IValueContainer<short?>.Value
			{
				get
				{
					string value = Value;
					if (string.IsNullOrEmpty(value))
						return null;
					
					return Convert.ToInt16(value);
				}
				set
				{
					if (value.HasValue)
						Value = value.Value.ToString();
					else
						Clear();
				}
			}
		#endregion
		#region IValueContainer<byte> Members
			byte IValueContainer<byte>.Value
			{
				get
				{
					return Convert.ToByte(Value);
				}
				set
				{
					Value = value.ToString();
				}
			}
		#endregion
		#region IValueContainer<byte?> Members
			byte? IValueContainer<byte?>.Value
			{
				get
				{
					string value = Value;
					if (string.IsNullOrEmpty(value))
						return null;
					
					return Convert.ToByte(value);
				}
				set
				{
					if (value.HasValue)
						Value = value.Value.ToString();
					else
						Clear();
				}
			}
		#endregion
		#region IValueContainer<sbyte> Members
			sbyte IValueContainer<sbyte>.Value
			{
				get
				{
					return Convert.ToSByte(Value);
				}
				set
				{
					Value = value.ToString();
				}
			}
		#endregion
		#region IValueContainer<sbyte?> Members
			sbyte? IValueContainer<sbyte?>.Value
			{
				get
				{
					string value = Value;
					if (string.IsNullOrEmpty(value))
						return null;
					
					return Convert.ToSByte(value);
				}
				set
				{
					if (value.HasValue)
						Value = value.Value.ToString();
					else
						Clear();
				}
			}
		#endregion
		#region IValueContainer<decimal> Members
			decimal IValueContainer<decimal>.Value
			{
				get
				{
					return Convert.ToDecimal(Value);
				}
				set
				{
					Value = value.ToString();
				}
			}
		#endregion
		#region IValueContainer<decimal?> Members
			decimal? IValueContainer<decimal?>.Value
			{
				get
				{
					string value = Value;
					if (string.IsNullOrEmpty(value))
						return null;
					
					return Convert.ToDecimal(value);
				}
				set
				{
					if (value.HasValue)
						Value = value.Value.ToString();
					else
						Clear();
				}
			}
		#endregion

		#region IHasPreferredDataType Members
			private PropertyInfo fPreferredValueProperty;
			
			/// <summary>
			/// Gets or sets the data-type used by the IValueContainer.Value property.
			/// </summary>
			public Type PreferredDataType
			{
				get
				{
					var property = fPreferredValueProperty;
					if (property == null)
						return null;
					
					return property.DeclaringType;
				}
				set
				{
					if (value == null)
					{
						fPreferredValueProperty = null;
						return;
					}
					
					Type type = typeof(IValueContainer<>).MakeGenericType(value);
					PropertyInfo propertyInfo = type.GetProperty("Value");
					fPreferredValueProperty = propertyInfo;
				}
			}
		#endregion
		#region IValueContainer<EmailString> Members
			EmailString IValueContainer<EmailString>.Value
			{
				get
				{
					return new EmailString(fTextBox.Text);
				}
				set
				{
					fTextBox.Text = value.ToString();
				}
			}
		#endregion
	}
}