Remove `elements` from MaterialNodePresenter. Sub-presenters are accessed through independent properties now.

Much simpler to work with and also less garbage generation :)

MaterialGraphProject/Assets/NewNodes/Editor/BlendModeNodePresenter.cs

     [Serializable]
     public class BlendModeNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/NewNodes/Editor/ConstantsNodePresenter.cs

     [Serializable]
     public class ConstantsNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/NewNodes/Editor/ToggleNodePresenter.cs

     [Serializable]
     public class ToggleNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/NewNodes/Editor/TransformNodePresenter.cs

     [Serializable]
     public class TransformNodePresenter : PropertyNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter>(base.GetControlData()) { instance };
+            return new List<GraphControlPresenter>(base.GetControlData()) { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/MaterialGraphPresenter.cs

                 var baseNode = addedNode.node;
                 foreach (var slot in baseNode.GetOutputSlots<ISlot>())
                 {
-                    var sourceAnchors = addedNode.elements.OfType<GraphAnchorPresenter>();
+                    var sourceAnchors = addedNode.outputAnchors.OfType<GraphAnchorPresenter>();
                     var sourceAnchor = sourceAnchors.FirstOrDefault(x => x.slot == slot);
 
                     var edges = baseNode.owner.GetEdges(new SlotReference(baseNode.guid, slot.id));
                         var toSlot = toNode.FindInputSlot<ISlot>(edge.inputSlot.slotId);
                         var targetNode = addedNodes.FirstOrDefault(x => x.node == toNode);
-                        var targetAnchors = targetNode.elements.OfType<GraphAnchorPresenter>();
+                        var targetAnchors = targetNode.inputAnchors.OfType<GraphAnchorPresenter>();
                         var targetAnchor = targetAnchors.FirstOrDefault(x => x.slot == toSlot);
 
                         var edgeData = CreateInstance<GraphEdgePresenter>();
                     var fromNode = graphAsset.graph.GetNodeFromGuid(edge.outputSlot.nodeGuid);
                     var fromSlot = fromNode.FindOutputSlot<ISlot>(edge.outputSlot.slotId);
                     var sourceNode = m_Elements.OfType<MaterialNodePresenter>().FirstOrDefault(x => x.node == fromNode);
-                    var sourceAnchors = sourceNode.elements.OfType<GraphAnchorPresenter>();
+                    var sourceAnchors = sourceNode.outputAnchors.OfType<GraphAnchorPresenter>();
-                    var targetAnchors = targetNode.elements.OfType<GraphAnchorPresenter>();
+                    var targetAnchors = targetNode.inputAnchors.OfType<GraphAnchorPresenter>();
                     var targetAnchor = targetAnchors.FirstOrDefault(x => x.slot == toSlot);
 
                     OnNodeChanged(targetNode.node, ModificationScope.Graph);

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/MaterialNodePresenter.cs

         public INode node { get; private set; }
 
         [SerializeField]
-        protected List<GraphElementPresenter> m_Controls = new List<GraphElementPresenter>();
+        protected List<GraphControlPresenter> m_Controls = new List<GraphControlPresenter>();
-        NodePreviewPresenter m_NodePreviewPresenter;
+        NodePreviewPresenter m_Preview;
 
         [SerializeField]
         int m_Version;
             get { return node is IRequiresTime; }
         }
 
-        public IEnumerable<GraphElementPresenter> elements
-        {
-            // TODO JOCE Sub ideal to use yield, but will do for now.
-            get
-            {
-                return inputAnchors.Concat(outputAnchors).Cast<GraphElementPresenter>().Concat(m_Controls).Concat(new [] {m_NodePreviewPresenter});
-            }
-        }
-
         public override bool expanded
         {
             get { return base.expanded; }
             }
         }
 
+        public List<GraphControlPresenter> controls
+        {
+            get { return m_Controls; }
+        }
+
+        public NodePreviewPresenter preview
+        {
+            get { return m_Preview; }
+        }
+
-            towatch.Add(m_NodePreviewPresenter);
+            towatch.Add(preview);
             return towatch.ToArray();
         }
 
             }
 
             // TODO: Propagate callback rather than setting property
-            if (m_NodePreviewPresenter != null)
-                m_NodePreviewPresenter.modificationScope = scope;
+            if (preview != null)
+                preview.modificationScope = scope;
         }
 
         public override void CommitChanges()
             node.drawState = drawState;
         }
 
-        protected virtual IEnumerable<GraphElementPresenter> GetControlData()
+        protected virtual IEnumerable<GraphControlPresenter> GetControlData()
-            return Enumerable.Empty<GraphElementPresenter>();
+            return Enumerable.Empty<GraphControlPresenter>();
         }
 
         protected void AddSlots(IEnumerable<ISlot> slots)
             AddSlots(node.GetSlots<ISlot>());
 
             var controlData = GetControlData();
-            m_Controls.AddRange(controlData);
+            controls.AddRange(controlData);
 
             position = new Rect(node.drawState.position.x, node.drawState.position.y, 0, 0);
 
             if (materialNode == null || !materialNode.hasPreview)
                 return;
 
-            m_NodePreviewPresenter = CreateInstance<NodePreviewPresenter>();
-            m_NodePreviewPresenter.Initialize(materialNode);
+            m_Preview = CreateInstance<NodePreviewPresenter>();
+            preview.Initialize(materialNode);
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/ColorNodePresenter.cs

     [Serializable]
     public class ColorNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/CubemapNodePresenter.cs

     [Serializable]
     public class CubeNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/GradientNodePresenter.cs

     [Serializable]
     public class GradientNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/IfNodePresenter.cs

     [Serializable]
     public class IfNodePresenter : PropertyNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter>(base.GetControlData()) { instance };
+            return new List<GraphControlPresenter>(base.GetControlData()) { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/LevelsNodePresenter.cs

     [Serializable]
     public class LevelsNodePresenter : PropertyNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter>(base.GetControlData()) { instance };
+            return new List<GraphControlPresenter>(base.GetControlData()) { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/MasterNodePresenter.cs

     [Serializable]
     public class MasterNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/Matrix2NodePresenter.cs

     [Serializable]
     public class Matrix2NodePresenter : PropertyNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter>(base.GetControlData()) { instance };
+            return new List<GraphControlPresenter>(base.GetControlData()) { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/Matrix3NodePresenter.cs

     [Serializable]
     public class Matrix3NodePresenter : PropertyNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter>(base.GetControlData()) { instance };
+            return new List<GraphControlPresenter>(base.GetControlData()) { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/Matrix4NodePresenter.cs

     [Serializable]
     public class Matrix4NodePresenter : PropertyNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter>(base.GetControlData()) { instance };
+            return new List<GraphControlPresenter>(base.GetControlData()) { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/MatrixCommonNodePresenter.cs

     [Serializable]
     public class MatrixCommonNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/RemapInputNodePresenter.cs

     [Serializable]
     public class RemapInputNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/RemapMasterNodePresenter.cs

     [Serializable]
     public class RemapMasterNodePresenter : MasterNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            var controls = new List<GraphElementPresenter>(base.GetControlData());
+            var controls = new List<GraphControlPresenter>(base.GetControlData());
             controls.Add(instance);
             return controls;
         }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/SamplerStateNodePresenter.cs

     [Serializable]
     public class SamplerStateNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/SubgraphIONodePresenter.cs

     [Serializable]
 	public class SubgraphIONodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/SubgraphNodePresenter.cs

     [Serializable]
     public class SubgraphNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/SurfaceMasterNodePresenter.cs

     [Serializable]
     public class SurfaceMasterNodePresenter : MasterNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            var controls = new List<GraphElementPresenter>(base.GetControlData());
+            var controls = new List<GraphControlPresenter>(base.GetControlData());
             controls.Add(instance);
             return controls;
         }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/SwizzleNodePresenter.cs

     [Serializable]
     public class SwizzleNodePresenter : PropertyNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter>(base.GetControlData()) { instance };
+            return new List<GraphControlPresenter>(base.GetControlData()) { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/TextureAssetNodePresenter.cs

     [Serializable]
     public class TextureAssetNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/TextureLODNodePresenter.cs

     [Serializable]
     public class TextureLODNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/TextureSamplerNodePresenter.cs

     [Serializable]
     public class TextureSamplerNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/UVNodePresenter.cs

     [Serializable]
     public class UVNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/Vector1NodePresenter.cs

     [Serializable]
     public class Vector1NodePresenter : PropertyNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter>(base.GetControlData()) { instance };
+            return new List<GraphControlPresenter>(base.GetControlData()) { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/Vector2NodePresenter.cs

     [Serializable]
     public class Vector2NodePresenter : PropertyNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter>(base.GetControlData()) { instance };
+            return new List<GraphControlPresenter>(base.GetControlData()) { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/Vector3NodePresenter.cs

     [Serializable]
     public class Vector3NodePresenter : PropertyNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter>(base.GetControlData()) { instance };
+            return new List<GraphControlPresenter>(base.GetControlData()) { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/Nodes/Vector4NodePresenter.cs

     [Serializable]
     public class Vector4NodePresenter : PropertyNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter>(base.GetControlData()) { instance };
+            return new List<GraphControlPresenter>(base.GetControlData()) { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/PropertyNodePresenter.cs

     [Serializable]
     public abstract class PropertyNodePresenter : MaterialNodePresenter
     {
-        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        protected override IEnumerable<GraphControlPresenter> GetControlData()
-            return new List<GraphElementPresenter> { instance };
+            return new List<GraphControlPresenter> { instance };
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Views/MaterialNodeView.cs

 
         void UpdateControls(MaterialNodePresenter nodeData)
         {
-            var controlPresenters = nodeData.elements.OfType<GraphControlPresenter>().ToList();
-
-            if (controlPresenters.SequenceEqual(m_CurrentControlPresenter) && nodeData.expanded)
+            if (nodeData.controls.SequenceEqual(m_CurrentControlPresenter) && nodeData.expanded)
                 return;
 
             m_ControlsContainer.Clear();
                 return;
 
-            foreach (var controlData in controlPresenters)
+            foreach (var controlData in nodeData.controls)
             {
                 m_ControlsContainer.Add(CreateControl(controlData));
                 m_CurrentControlPresenter.Add(controlData);
 
             UpdateControls(nodeData);
 
-            m_CurrentPreviewData = nodeData.elements.OfType<NodePreviewPresenter>().FirstOrDefault();
+            m_CurrentPreviewData = nodeData.preview;
             UpdatePreviewTexture(m_CurrentPreviewData);
 
             if (nodeData.expanded)