Support Old Value on Property Change

Author: jogibear9988

WpfDesign.Designer/Project/Xaml/XamlComponentService.cs

@@ -201,11 +201,11 @@ internal XamlDesignItem RegisterXamlComponentRecursive(XamlObject obj)
 		/// <summary>
 		/// raises the Property changed Events
 		/// </summary>
-		internal void RaisePropertyChanged(XamlModelProperty property)
+		internal void RaisePropertyChanged(XamlModelProperty property, object oldValue, object newValue)
 		{
 			var ev = this.PropertyChanged;
 			if (ev != null) {
-				ev(this, new DesignItemPropertyChangedEventArgs(property.DesignItem, property));
+				ev(this, new DesignItemPropertyChangedEventArgs(property.DesignItem, property, oldValue, newValue));
 			}
 		}
 

WpfDesign.Designer/Project/Xaml/XamlDesignItem.cs

@@ -264,12 +264,12 @@ public override IEnumerable<DesignItemProperty> AllSetProperties {
 			get { return _xamlObject.Properties.Select(x => new XamlModelProperty(this, x)); }
 		}
 
-		internal void NotifyPropertyChanged(XamlModelProperty property)
+		internal void NotifyPropertyChanged(XamlModelProperty property, object oldValue, object newValue)
 		{
 			Debug.Assert(property != null);
 			OnPropertyChanged(new System.ComponentModel.PropertyChangedEventArgs(property.Name));
 
-			((XamlComponentService)this.Services.Component).RaisePropertyChanged(property);
+			((XamlComponentService)this.Services.Component).RaisePropertyChanged(property, oldValue, newValue);
 		}
 
 		public override string ContentPropertyName {

WpfDesign.Designer/Project/Xaml/XamlModelCollectionElementsCollection.cs

@@ -260,13 +260,13 @@ public string Title {
 			public void Do()
 			{
 				collection.InsertInternal(index, item);
-				collection.modelProperty.XamlDesignItem.NotifyPropertyChanged(collection.modelProperty);
+				collection.modelProperty.XamlDesignItem.NotifyPropertyChanged(collection.modelProperty, null, item);
 			}
 
 			public void Undo()
 			{
 				collection.RemoveInternal(index, item);
-				collection.modelProperty.XamlDesignItem.NotifyPropertyChanged(collection.modelProperty);
+				collection.modelProperty.XamlDesignItem.NotifyPropertyChanged(collection.modelProperty, item, null);
 			}
 
 			public bool MergeWith(ITransactionItem other)
@@ -303,13 +303,13 @@ public string Title {
 			public void Do()
 			{
 				collection.RemoveInternal(index, item);
-				collection.modelProperty.XamlDesignItem.NotifyPropertyChanged(collection.modelProperty);
+				collection.modelProperty.XamlDesignItem.NotifyPropertyChanged(collection.modelProperty, item ,null);
 			}
 
 			public void Undo()
 			{
 				collection.InsertInternal(index, item);
-				collection.modelProperty.XamlDesignItem.NotifyPropertyChanged(collection.modelProperty);
+				collection.modelProperty.XamlDesignItem.NotifyPropertyChanged(collection.modelProperty, null, item);
 			}
 
 			public bool MergeWith(ITransactionItem other)
@@ -340,14 +340,14 @@ public void Do()
 				for (int i = items.Length - 1; i >= 0; i--) {
 					collection.RemoveInternal(i, items[i]);
 				}
-				collection.modelProperty.XamlDesignItem.NotifyPropertyChanged(collection.modelProperty);
+				collection.modelProperty.XamlDesignItem.NotifyPropertyChanged(collection.modelProperty, items, null);
 			}
 			public void Undo()
 			{
 				for (int i = 0; i < items.Length; i++) {
 					collection.InsertInternal(i, items[i]);
 				}
-				collection.modelProperty.XamlDesignItem.NotifyPropertyChanged(collection.modelProperty);
+				collection.modelProperty.XamlDesignItem.NotifyPropertyChanged(collection.modelProperty, null, items);
 			}
 			public bool MergeWith(ITransactionItem other)
 			{

WpfDesign.Designer/Project/Xaml/XamlModelProperty.cs

@@ -247,8 +247,9 @@ public override void SetValue(object value)
 
 		void SetValueInternal(XamlPropertyValue newValue)
 		{
+			var oldValue = _property.PropertyValue;
 			_property.PropertyValue = newValue;
-			_designItem.NotifyPropertyChanged(this);
+			_designItem.NotifyPropertyChanged(this, oldValue, newValue);
 		}
 
 		public override void Reset()
@@ -262,9 +263,11 @@ public override void Reset()
 
 		void ResetInternal()
 		{
-			if (_property.IsSet) {
+			if (_property.IsSet)
+			{
+				var oldValue = _property.PropertyValue;
 				_property.Reset();
-				_designItem.NotifyPropertyChanged(this);
+				_designItem.NotifyPropertyChanged(this, oldValue, null);
 			}
 		}
 

WpfDesign/Project/EventArgs.cs

@@ -50,21 +50,48 @@ public DesignItem Item {
 	public class DesignItemPropertyChangedEventArgs : DesignItemEventArgs
 	{
 		readonly DesignItemProperty _itemProperty;
-
+		readonly object _oldValue;
+		readonly object _newValue;
+
 		/// <summary>
 		/// Creates a new ComponentEventArgs instance.
 		/// </summary>
 		public DesignItemPropertyChangedEventArgs(DesignItem item, DesignItemProperty itemProperty) : base(item)
 		{
 			_itemProperty = itemProperty;
 		}
-		
+
+		/// <summary>
+		/// Creates a new ComponentEventArgs instance.
+		/// </summary>
+		public DesignItemPropertyChangedEventArgs(DesignItem item, DesignItemProperty itemProperty, object oldValue, object newValue) : this(item, itemProperty)
+		{
+			_oldValue = oldValue;
+			_newValue = newValue;
+		}
+
 		/// <summary>
 		/// The property affected by the event.
 		/// </summary>
 		public DesignItemProperty ItemProperty {
 			get { return _itemProperty; }
 		}
+
+		/// <summary>
+		/// Previous Value
+		/// </summary>
+		public object OldValue
+		{
+			get { return _oldValue; }
+		}
+
+		/// <summary>
+		/// New Value
+		/// </summary>
+		public object NewValue
+		{
+			get { return _newValue; }
+		}
 	}
 
 	/// <summary>