Wire up notification system for ContentChanged -> UI listeners

Library/Interfaces/ILibraryContainer.cs

@@ -59,6 +59,8 @@ namespace MatterHackers.MatterControl.Library
 
 	public interface ILibraryWritableContainer : ILibraryContainer
 	{
+		event EventHandler<ItemChangedEventArgs> ItemContentChanged;
+
 		void Add(IEnumerable<ILibraryItem> items);
 		void Remove(IEnumerable<ILibraryItem> items);
 		void Rename(ILibraryItem item, string revisedName);
@@ -75,4 +77,14 @@ namespace MatterHackers.MatterControl.Library
 		RenameItems,
 		RemoveItems
 	}
+
+	public class ItemChangedEventArgs : EventArgs
+	{
+		public ILibraryItem LibraryItem { get; }
+
+		public ItemChangedEventArgs(ILibraryItem libraryItem)
+		{
+			this.LibraryItem = libraryItem;
+		}
+	}
 }

Library/Providers/FileSystem/FileSystemItem.cs

@@ -69,4 +69,15 @@ namespace MatterHackers.MatterControl.Library
 			}
 		}
 	}
+
+	public class MockLibraryItem : ILibraryItem
+	{
+		public string ID { get; set; }
+
+		public string Name { get; set; }
+
+		public bool IsProtected => true;
+
+		public bool IsVisible => true;
+	}
 }

Library/Providers/WritableContainer.cs

@@ -27,6 +27,7 @@ of the authors and should not be interpreted as representing official policies,
 either expressed or implied, of the FreeBSD Project.
 */
 
+using System;
 using System.Collections.Generic;
 using MatterHackers.Agg.Image;
 
@@ -34,6 +35,13 @@ namespace MatterHackers.MatterControl.Library
 {
 	public abstract class WritableContainer : LibraryContainer, ILibraryWritableContainer
 	{
+		public event EventHandler<ItemChangedEventArgs> ItemContentChanged;
+
+		public virtual void OnItemContentChanged(ItemChangedEventArgs args)
+		{
+			ItemContentChanged?.Invoke(this, args);
+		}
+
 		public virtual void Add(IEnumerable<ILibraryItem> items)
 		{
 		}

Library/Widgets/ListView/ListView.cs

@@ -132,6 +132,11 @@ namespace MatterHackers.MatterControl.CustomWidgets
 		/// <param name="sourceContainer">The container to load</param>
 		private void DisplayContainerContent(ILibraryContainer sourceContainer)
 		{
+			if (this.ActiveContainer is ILibraryWritableContainer activeWritable)
+			{
+				activeWritable.ItemContentChanged -= WritableContainer_ItemContentChanged;
+			}
+
 			UiThread.RunOnIdle(() =>
 			{
 				if (sourceContainer == null)
@@ -180,10 +185,25 @@ namespace MatterHackers.MatterControl.CustomWidgets
 					}
 				}
 
+				if (sourceContainer is ILibraryWritableContainer writableContainer)
+				{
+					writableContainer.ItemContentChanged += WritableContainer_ItemContentChanged;
+				}
+
 				this.Invalidate();
 			});
 		}
 
+		private void WritableContainer_ItemContentChanged(object sender, ItemChangedEventArgs e)
+		{
+			var firstItem = items.Where(i => i.Model.ID == e.LibraryItem.ID).FirstOrDefault();
+			if (firstItem != null)
+			{
+				firstItem.ViewWidget.LoadItemThumbnail().ConfigureAwait(false);
+				firstItem.ViewWidget.Invalidate();
+			}
+		}
+
 		public enum ViewMode
 		{
 			Icons,

Library/Widgets/ListView/ListViewItemBase.cs

@@ -88,7 +88,7 @@ namespace MatterHackers.MatterControl.CustomWidgets
 			return true;
 		}
 
-		protected async Task LoadItemThumbnail()
+		public async Task LoadItemThumbnail()
 		{
 			var listView = listViewItem.ListView;