Add Sketch file support to ThumbnailViewer plugin

QuickLook.Plugin/QuickLook.Plugin.ThumbnailViewer/Handler.cs

@@ -74,6 +74,20 @@ internal static class Handler
                 context.PreferredSize = new Size { Width = 100, Height = 100 };
             }
         }
+        else if (path.EndsWith(".sketch", StringComparison.OrdinalIgnoreCase))
+        {
+            try
+            {
+                using Stream imageData = ViewImage(path);
+                BitmapImage bitmap = imageData.ReadAsBitmapImage();
+                context.SetPreferredSizeFit(new Size(bitmap.PixelWidth, bitmap.PixelHeight), 0.8d);
+            }
+            catch (Exception e)
+            {
+                _ = e;
+                context.PreferredSize = new Size { Width = 100, Height = 100 };
+            }
+        }
         else if (path.EndsWith(".xmind", StringComparison.OrdinalIgnoreCase))
         {
             try
@@ -195,6 +209,22 @@ internal static class Handler
             StreamResourceInfo info = Application.GetResourceStream(new Uri("pack://application:,,,/QuickLook.Plugin.ThumbnailViewer;component/Resources/broken.png"));
             return info?.Stream;
         }
+        else if (path.EndsWith(".sketch", StringComparison.OrdinalIgnoreCase))
+        {
+            using ZipArchive archive = ZipArchive.Open(path, new());
+            using IReader reader = archive.ExtractAllEntries();
+
+            while (reader.MoveToNextEntry())
+            {
+                if (reader.Entry.Key!.EndsWith("previews/preview.png", StringComparison.OrdinalIgnoreCase))
+                {
+                    MemoryStream ms = new();
+                    using EntryStream stream = reader.OpenEntryStream();
+                    stream.CopyTo(ms);
+                    return ms;
+                }
+            }
+        }
         else if (path.EndsWith(".xmind", StringComparison.OrdinalIgnoreCase))
         {
             using ZipArchive archive = ZipArchive.Open(path, new());

QuickLook.Plugin/QuickLook.Plugin.ThumbnailViewer/Plugin.cs

@@ -34,6 +34,7 @@ public class Plugin : IViewer
         ".fig", // Figma
         ".kra", // Krita
         ".pip", ".pix", // Pixso
+        ".sketch", // Sketch
         ".xd", // AdobeXD
         ".xmind", // XMind
     ]);