port from perforce

intromat/NodeNetworkToolkit/ValueNode/ValueNodeInputViewModelBase.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Reactive;
+using NodeNetwork.ViewModels;
+
+namespace NodeNetwork.Toolkit.ValueNode
+{
+    public abstract class ValueNodeInputViewModelBase : NodeInputViewModel
+    {
+
+        #region ValueChanged
+        /// <summary>
+        /// An observable that fires when the input value changes. 
+        /// This may be because of a connection change, editor value change, network validation change, ...
+        /// </summary>
+        public abstract IObservable<Unit> UnitValueChanged { get; } 
+        #endregion
+    }
+}