Item-Level Presentation Models for WPF

using System.ComponentModel;

namespace HappyNomad.PresentationModel {

	/// <summary>Presentation-tailored representation of a domain-model type.</summary>
	/// <typeparam name="DMType">The domain-model type to be wrapped</typeparam>
	/// <author>Adrian Alexander</author>
	public abstract class ItemPresentationModel<DMType> : INotifyPropertyChanged where DMType : class {

		#region 'DomainItem' Property

		private DMType domainItem;

		public DMType DomainItem {
			get { return domainItem; }
			set { domainItem = value; }
		}

		protected ItemPresentationModel( DMType domainItem ) {
			this.domainItem = domainItem;
		}

		#endregion

		#region 'IsSelected' Property

		private bool isSelected;

		/// <summary>
		/// Is the TreeViewItem associated with this object selected?
		/// [Source: http://www.codeproject.com/KB/WPF/TreeViewWithViewModel.aspx ]
		/// </summary>
		public bool IsSelected {
			get { return isSelected; }
			set {
				if ( value != isSelected ) {
					isSelected = value;
					this.OnPropertyChanged( "IsSelected" );
				}
			}
		}

		#endregion // IsSelected

		#region 'INotifyPropertyChanged' Members

		public event PropertyChangedEventHandler PropertyChanged;

		protected virtual void OnPropertyChanged( string propertyName ) {
			if ( this.PropertyChanged != null )
				this.PropertyChanged( this, new PropertyChangedEventArgs( propertyName ) );
		}

		#endregion // INotifyPropertyChanged Members

		#region 'Object.Equals' Method

		public override bool Equals( object obj ) {
			DMType compareTo = obj as DMType;

			if ( compareTo == null ) {
				ItemPresentationModel<DMType> itemWrapper = obj as ItemPresentationModel<DMType>;
				if ( itemWrapper == null ) return false;
				else compareTo = itemWrapper.domainItem;
			}
			return domainItem.Equals( compareTo );
		}

		public override int GetHashCode() {
			return domainItem.GetHashCode();
		}

		#endregion //Object.Equals Method

		public override string ToString() {
			return GetType().Name + ": DomainItem={" + domainItem + "}";
		}
	}
}