fix threading bug with logging in ui

Author: LeftofZen

Gui/ViewModels/Graphics/ImageViewModel.cs

@@ -77,8 +77,16 @@ public GraphicsElementFlags Flags
 	[Reactive, Browsable(false)]
 	public Bitmap DisplayedImage { get; private set; }
 
-	[Reactive, Browsable(false)]
-	public Image<Rgba32> UnderlyingImage { get; set; }
+	[Browsable(false)]
+	public Image<Rgba32> UnderlyingImage
+	{
+		get => Model.Image!;
+		set
+		{
+			Model.Image = value;
+			this.RaisePropertyChanged(nameof(UnderlyingImage));
+		}
+	}
 
 	[Browsable(false)]
 	public Avalonia.Rect SelectedBitmapPreviewBorder
@@ -98,7 +106,7 @@ public ImageViewModel(GraphicsElement graphicsElement)
 
 		_ = this.WhenAnyValue(o => o.UnderlyingImage)
 			.Where(x => x != null)
-			.Subscribe(_ => UnderlyingImageChanged());
+			.Subscribe(_ => DisplayedImage = UnderlyingImage!.ToAvaloniaBitmap());
 
 		_ = this.WhenAnyValue(o => o.DisplayedImage)
 			.Subscribe(_ => this.RaisePropertyChanged(nameof(SelectedBitmapPreviewBorder)));
@@ -133,9 +141,6 @@ public void RecolourImage(ColourSwatch primary, ColourSwatch secondary, PaletteM
 		DisplayedImage = image!.ToAvaloniaBitmap();
 	}
 
-	void UnderlyingImageChanged()
-		=> DisplayedImage = UnderlyingImage!.ToAvaloniaBitmap();
-
 	public void CropImage()
 	{
 		var cropRegion = FindCropRegion(UnderlyingImage);
@@ -153,7 +158,7 @@ public void CropImage()
 			YOffset += (short)cropRegion.Top;
 		}
 
-		UnderlyingImageChanged();
+		this.RaisePropertyChanged(nameof(UnderlyingImage));
 
 		static Rectangle FindCropRegion(Image<Rgba32> image)
 		{

Gui/ViewModels/MainWindowViewModel.cs

@@ -101,12 +101,16 @@ public MainWindowViewModel()
 				var log = laea.Log;
 				if (log.Level is LogLevel.Error)
 				{
-					// check if the logs window is already open
-					if (App.GetOpenWindows().Any(x => x.DataContext is LogWindowViewModel))
+					// Dispatch the UI-related work to the UI thread.
+					Avalonia.Threading.Dispatcher.UIThread.Post(() =>
 					{
-						return;
-					}
-					ShowLogsCommand.Execute();
+						// check if the logs window is already open
+						if (App.GetOpenWindows().Any(x => x.DataContext is LogWindowViewModel))
+						{
+							return;
+						}
+						ShowLogsCommand.Execute();
+					});
 				}
 			}
 		};