Add batching undo actions for Surface editing to prevent undo actions spam during a single edit

Source/Editor/Surface/Archetypes/Animation.StateMachine.cs

@@ -1389,7 +1389,7 @@ namespace FlaxEditor.Surface.Archetypes
                 var state = (StateMachineState)other;
 
                 var action = new AddRemoveTransitionAction(this, state);
-                Surface?.Undo.AddAction(action);
+                Surface?.AddBatchedUndoAction(action);
                 action.Do();
                 Surface?.OnNodesConnected(this, other);
             }
@@ -1718,7 +1718,7 @@ namespace FlaxEditor.Surface.Archetypes
             public void Delete()
             {
                 var action = new StateMachineState.AddRemoveTransitionAction(this);
-                SourceState.Surface?.Undo.AddAction(action);
+                SourceState.Surface?.AddBatchedUndoAction(action);
                 action.Do();
             }
 

Source/Editor/Surface/Elements/Box.cs

@@ -437,7 +437,7 @@ namespace FlaxEditor.Surface.Elements
                             var action = new EditNodeConnections(ParentNode.Context, ParentNode);
                             RemoveConnections(1);
                             action.End();
-                            Surface.Undo.AddAction(action);
+                            Surface.AddBatchedUndoAction(action);
                         }
                         else
                         {
@@ -629,7 +629,7 @@ namespace FlaxEditor.Surface.Elements
                             var action = new ConnectBoxesAction((InputBox)this, (OutputBox)connectedBox, false);
                             BreakConnection(connectedBox);
                             action.End();
-                            Surface.Undo.AddAction(action);
+                            Surface.AddBatchedUndoAction(action);
                             Surface.MarkAsEdited();
                         }
                         else
@@ -678,7 +678,7 @@ namespace FlaxEditor.Surface.Elements
                             var action = new EditNodeConnections(ParentNode.Context, ParentNode);
                             RemoveConnections();
                             action.End();
-                            Surface.Undo.AddAction(action);
+                            Surface.AddBatchedUndoAction(action);
                         }
                         else
                         {
@@ -856,7 +856,7 @@ namespace FlaxEditor.Surface.Elements
                     var action = new ConnectBoxesAction(iB, oB, false);
                     start.BreakConnection(end);
                     action.End();
-                    Surface.Undo.AddAction(action);
+                    Surface.AddBatchedUndoAction(action);
                 }
                 else
                 {
@@ -892,7 +892,7 @@ namespace FlaxEditor.Surface.Elements
                     var action = new ConnectBoxesAction(iB, oB, true);
                     iB.CreateConnection(oB);
                     action.End();
-                    Surface.Undo?.AddAction(action);
+                    Surface.AddBatchedUndoAction(action);
                 }
                 else
                 {

Source/Editor/Surface/SurfaceNode.cs

@@ -926,7 +926,8 @@ namespace FlaxEditor.Surface
             OnValuesChanged();
             Surface?.MarkAsEdited(graphEdited);
 
-            Surface?.Undo?.AddAction(new EditNodeValuesAction(this, before, graphEdited));
+            if (Surface?.Undo != null)
+                Surface.AddBatchedUndoAction(new EditNodeValuesAction(this, before, graphEdited));
 
             _isDuringValuesEditing = false;
         }
@@ -952,7 +953,8 @@ namespace FlaxEditor.Surface
             OnValuesChanged();
             Surface.MarkAsEdited(graphEdited);
 
-            Surface.Undo?.AddAction(new EditNodeValuesAction(this, before, graphEdited));
+            if (Surface?.Undo != null)
+                Surface.AddBatchedUndoAction(new EditNodeValuesAction(this, before, graphEdited));
 
             _isDuringValuesEditing = false;
         }

Source/Editor/Surface/VisjectSurface.Draw.cs

@@ -49,6 +49,13 @@ namespace FlaxEditor.Surface
             _moveViewWithMouseDragSpeed = isMovingWithMouse ? Mathf.Clamp(_moveViewWithMouseDragSpeed + deltaTime * 20.0f, 1.0f, 8.0f) : 1.0f;
 
             base.Update(deltaTime);
+
+            // Batch undo actions
+            if (_batchedUndoActions != null && _batchedUndoActions.Count != 0)
+            {
+                Undo.AddAction(_batchedUndoActions.Count == 1 ? _batchedUndoActions[0] : new MultiUndoAction(_batchedUndoActions));
+                _batchedUndoActions.Clear();
+            }
         }
 
         /// <summary>

Source/Editor/Surface/VisjectSurface.cs

@@ -38,6 +38,7 @@ namespace FlaxEditor.Surface
         private VisjectCM _activeVisjectCM;
         private GroupArchetype _customNodesGroup;
         private List<NodeArchetype> _customNodes;
+        private List<IUndoAction> _batchedUndoActions;
         private Action _onSave;
         private int _selectedConnectionIndex;
 
@@ -901,6 +902,19 @@ namespace FlaxEditor.Surface
         {
             return _context.FindNode(id);
         }
+        
+        /// <summary>
+        /// Adds the undo action to be batched (eg. if multiple undo actions is performed in a sequence during single update).
+        /// </summary>
+        /// <param name="action">The action.</param>
+        public void AddBatchedUndoAction(IUndoAction action)
+        {
+            if (Undo == null || !Undo.Enabled)
+                return;
+            if (_batchedUndoActions == null)
+                _batchedUndoActions = new List<IUndoAction>();
+            _batchedUndoActions.Add(action);
+        }
 
         /// <summary>
         /// Called when node gets spawned in the surface (via UI).