fixed drag drop to 3d view

MatterControlLib/Library/Providers/FileSystem/FileSystemFileItem.cs

@@ -74,4 +74,15 @@ namespace MatterHackers.MatterControl.Library
 			return Task.FromResult<StreamAndLength>(null);
 		}
 	}
+
+	/// <summary>
+	/// This class is specifically used for drag drop of scene replacement files
+	/// </summary>
+    public class SceneReplacementFileItem : FileSystemFileItem
+    {
+        public SceneReplacementFileItem(string filePath)
+            : base(filePath)
+        {
+        }
+    }
 }

MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs

@@ -1233,7 +1233,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 
 			if ((firstItem is ILibraryAssetStream contentStream
 				&& contentStream.ContentType == "gcode")
-				|| firstItem is FileSystemFileItem)
+				|| firstItem is SceneReplacementFileItem)
 			{
 				DragDropObject = null;
 				this.SceneReplacement = firstItem as ILibraryAssetStream;

MatterControlLib/PartPreviewWindow/ViewToolBarControls.cs

@@ -610,7 +610,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 					int maxItemWidth = 0;
 
 					var recentFiles = new DirectoryInfo(ApplicationDataStorage.Instance.PlatingDirectory).GetFiles("*.mcx").OrderByDescending(f => f.LastWriteTime);
-					foreach (var item in recentFiles.Where(f => f.Length > 215).Select(f => new FileSystemFileItem(f.FullName)).Take(12))
+					foreach (var item in recentFiles.Where(f => f.Length > 215).Select(f => new SceneReplacementFileItem(f.FullName)).Take(12))
 					{
 						var imageBuffer = new ImageBuffer(thumbWidth, thumbWidth);
 

Submodules/agg-sharp

@@ -1 +1 @@
-Subproject commit bb22b896576d4871774b966af45546b3509edf9a
+Subproject commit ccb6fd61762931e024e0517e287925560c835c9e