port from perforce

intromat/Intromat/Nodes/ExecutionNodeBase.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Reactive;
+using System.Reactive.Linq;
+using DynamicData;
+using Intromat.Model.Compiler;
+using Intromat.ViewModels;
+using NodeNetwork.Toolkit.ValueNode;
+using NodeNetwork.ViewModels;
+
+namespace Intromat.Nodes
+{
+    public abstract class ExecutionNodeBase : CodeGenNodeViewModel
+    {
+        protected readonly EndpointGroup _executionFlowGroup;
+
+        protected ExecutionNodeBase(NodeType type)
+            : base(type)
+        {
+            _executionFlowGroup = new EndpointGroup("Execution Flow");
+
+            FlowOut = new CodeGenInputViewModel<IStatement>(EPortType.Execution)
+            {
+                Name = "Flow",
+                Group = _executionFlowGroup
+            };
+            Inputs.Add(FlowOut);
+
+            FlowOutChanged = FlowOut.ValueChanged.Select(_ => Unit.Default).StartWith(Unit.Default);
+            
+            FlowIn = new CodeGenOutputViewModel<IStatement>(EPortType.Execution)
+            {
+                Name = "Flow",
+                Group = _executionFlowGroup
+            };
+            Outputs.Add(FlowIn);
+        }
+
+        public ValueNodeOutputViewModel<IStatement> FlowIn { get; }
+
+        public ValueNodeInputViewModel<IStatement> FlowOut { get; }
+
+        public IObservable<Unit> FlowOutChanged { get; }
+    }
+}