Add change notifications for graph, used for managing previews better

MaterialGraphProject/Assets/GraphFramework/SerializableGraph/Runtime/Implementation/SerializableGraph.cs

         {
             m_Nodes.Add(node.guid, node);
             node.owner = this;
+            NotifyChange(new NodeAddedGraphChange(node));
             ValidateGraph();
         }
 
                 return;
 
             m_Nodes.Remove(node.guid);
+            NotifyChange(new NodeRemovedGraphChange(node));
             ValidateGraph();
         }
 
                 return;
 
             m_Nodes.Remove(node.guid);
+            NotifyChange(new NodeRemovedGraphChange(node));
         }
 
         void AddEdgeToNodeEdges(IEdge edge)
             {
                 node.OnEnable();
             }
+        }
+
+        public OnGraphChange onChange { get; set; }
+
+        void NotifyChange(GraphChange change)
+        {
+            if (onChange != null)
+                onChange(change);
         }
     }
 }

MaterialGraphProject/Assets/GraphFramework/SerializableGraph/Runtime/Interfaces/IGraph.cs

 
 namespace UnityEngine.Graphing
 {
+    public delegate void OnGraphChange(GraphChange change);
+
     public interface IGraph : IOnAssetEnabled
     {
         IEnumerable<T> GetNodes<T>() where T : INode;
         T GetNodeFromGuid<T>(Guid guid) where T : INode;
         IEnumerable<IEdge> GetEdges(SlotReference s);
         void ValidateGraph();
+        OnGraphChange onChange { get; set; }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Inspector/GraphInspectorPresenter.cs

 {
     public class GraphInspectorPresenter : ScriptableObject, IDisposable
     {
-        PreviewHandle m_PreviewHandle;
+        PreviewData m_PreviewHandle;
 
         public IGraph graph { get; set; }
 
             var masterNode = graph.GetNodes<AbstractMasterNode>().FirstOrDefault();
             if (masterNode != null)
             {
-                m_PreviewHandle = previewSystem.GetPreviewHandle(masterNode.guid);
+                m_PreviewHandle = previewSystem.GetPreview(masterNode);
                 m_PreviewHandle.onPreviewChanged += OnPreviewChanged;
             }
             this.graph = graph;
         {
             if (m_PreviewHandle != null)
             {
-                m_PreviewHandle.Dispose();
+                m_PreviewHandle.onPreviewChanged -= OnPreviewChanged;
                 m_PreviewHandle = null;
             };
         }

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

 
         [SerializeField]
         int m_Version;
-
-        PreviewHandle m_PreviewHandle;
+        PreviewData m_Preview;
 
         public Texture previewTexture { get; private set; }
 
 
             m_Version = 0;
 
-            m_PreviewHandle = previewSystem.GetPreviewHandle(inNode.guid);
-            m_PreviewHandle.onPreviewChanged += OnPreviewChanged;
+            m_Preview = previewSystem.GetPreview(inNode);
+            m_Preview.onPreviewChanged += OnPreviewChanged;
-            previewTexture = m_PreviewHandle.texture;
+            previewTexture = m_Preview.texture;
-            if (m_PreviewHandle != null)
+            if (m_Preview != null)
-                m_PreviewHandle.Dispose();
-                m_PreviewHandle = null;
+                m_Preview.onPreviewChanged -= OnPreviewChanged;
+                m_Preview = null;
             }
         }
     }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/PreviewSystem.cs

-using System;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
             m_ErrorTexture.SetPixel(1, 0, Color.black);
             m_ErrorTexture.SetPixel(1, 1, Color.magenta);
             m_ErrorTexture.Apply();
+
+            m_Graph.onChange += OnGraphChange;
+
+            foreach (var node in m_Graph.GetNodes<INode>())
+                AddPreview(node);
-        public PreviewHandle GetPreviewHandle(Guid nodeGuid)
+        public PreviewData GetPreview(INode node)
+        {
+            return m_Previews[node.guid];
+        }
+
+        void OnGraphChange(GraphChange change)
+        {
+            if (change is NodeAddedGraphChange)
+                AddPreview(((NodeAddedGraphChange)change).node);
+            else if (change is NodeRemovedGraphChange)
+                RemovePreview(((NodeRemovedGraphChange)change).node);
+        }
+
+        void AddPreview(INode node)
-            PreviewData previewData;
-            if (!m_Previews.TryGetValue(nodeGuid, out previewData))
+            var previewData = new PreviewData
-                var node = m_Graph.GetNodeFromGuid(nodeGuid);
-                if (node == null)
-                    throw new ArgumentException("Node does not exist.", "nodeGuid");
-                previewData = new PreviewData();
-                previewData.renderTexture = new RenderTexture(256, 256, 16, RenderTextureFormat.ARGB32, RenderTextureReadWrite.Default) { hideFlags = HideFlags.HideAndDontSave };
-                m_Previews.Add(nodeGuid, previewData);
-                m_DirtyShaders.Add(nodeGuid);
-                m_DirtyPreviews.Add(nodeGuid);
-                node.onModified += OnNodeModified;
-            }
-            previewData.refCount++;
-            return new PreviewHandle(nodeGuid, previewData, this);
+                renderTexture = new RenderTexture(256, 256, 16, RenderTextureFormat.ARGB32, RenderTextureReadWrite.Default) { hideFlags = HideFlags.HideAndDontSave }
+            };
+            m_Previews.Add(node.guid, previewData);
+            m_DirtyShaders.Add(node.guid);
+            node.onModified += OnNodeModified;
+        }
+
+        void RemovePreview(INode node)
+        {
+            node.onModified -= OnNodeModified;
+            m_Previews.Remove(node.guid);
         }
 
         void OnNodeModified(INode node, ModificationScope scope)
             }
         }
 
-        public void DestroyPreviewHandle(Guid nodeGuid)
-        {
-            PreviewData previewData;
-            if (!m_Previews.TryGetValue(nodeGuid, out previewData))
-                return;
-            previewData.refCount--;
-            if (previewData.refCount == 0)
-                DestroyPreview(nodeGuid, previewData);
-        }
-
         void DestroyPreview(Guid nodeGuid, PreviewData previewData)
         {
             if (m_Previews.Remove(nodeGuid))
         public PreviewMode previewMode { get; set; }
         public RenderTexture renderTexture { get; set; }
         public Texture texture { get; set; }
-        public int refCount { get; set; }
-    }
-
-    public class PreviewHandle : IDisposable
-    {
-        Guid m_NodeGuid;
-        PreviewData m_PreviewData;
-        PreviewSystem m_PreviewSystem;
-
-        public PreviewHandle(Guid nodeGuid, PreviewData previewData, PreviewSystem previewSystem)
-        {
-            m_NodeGuid = nodeGuid;
-            m_PreviewData = previewData;
-            m_PreviewSystem = previewSystem;
-        }
-
-        public OnPreviewChanged onPreviewChanged
-        {
-            get { return m_PreviewData.onPreviewChanged; }
-            set { m_PreviewData.onPreviewChanged = value; }
-        }
-
-        public Texture texture
-        {
-            get { return m_PreviewData.texture; }
-        }
-
-        void ReleaseUnmanagedResources()
-        {
-            m_PreviewSystem.DestroyPreviewHandle(m_NodeGuid);
-        }
-
-        public void Dispose()
-        {
-            ReleaseUnmanagedResources();
-            GC.SuppressFinalize(this);
-        }
-
-        ~PreviewHandle()
-        {
-            ReleaseUnmanagedResources();
-        }
     }
 }

MaterialGraphProject/Assets/GraphFramework/SerializableGraph/Runtime/Interfaces/GraphChange.cs

+namespace UnityEngine.Graphing
+{
+    public abstract class GraphChange {}
+
+    public sealed class NodeAddedGraphChange : GraphChange
+    {
+        public NodeAddedGraphChange(INode node)
+        {
+            this.node = node;
+        }
+
+        public INode node { get; private set; }
+    }
+
+    public sealed class NodeRemovedGraphChange : GraphChange
+    {
+        public NodeRemovedGraphChange(INode node)
+        {
+            this.node = node;
+        }
+
+        public INode node { get; private set; }
+    }
+}

MaterialGraphProject/Assets/GraphFramework/SerializableGraph/Runtime/Interfaces/GraphChange.cs.meta

+fileFormatVersion: 2
+guid: cbfac7ed81744ca281be9e21eae861c7
+timeCreated: 1505620762