Refactor custom drawing operation.

QuestPDF.Previewer/PreviewerControl.cs

@@ -65,7 +65,9 @@ namespace QuestPDF.Previewer
             if (_renderer.Picture == null)
                 return;
 
-            context.Custom(new SkPictureRenderOperation(_renderer.Picture, new Rect(0, 0, Bounds.Width, Bounds.Height)));
+            context.Custom(new SkCustomDrawOperation(
+                new Rect(0, 0, Bounds.Width, Bounds.Height),
+                c => c.DrawPicture(_renderer.Picture)));
         }
 
         internal void InvalidateDocument()

QuestPDF.Previewer/PreviewerWindow.axaml

@@ -23,7 +23,7 @@
 			</ExperimentalAcrylicBorder.Material>
 		</ExperimentalAcrylicBorder>
 
-		<Grid Margin="0,40,0,0">
+		<Grid Margin="10,40,10,0">
 			<Grid.RowDefinitions>
 				<RowDefinition Height="40"/>
 				<RowDefinition Height="*"/>

QuestPDF.Previewer/PreviewerWindow.axaml.cs

@@ -1,8 +1,6 @@
-using System.Diagnostics;
-using Avalonia;
+using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
-using QuestPDF.Fluent;
 using QuestPDF.Infrastructure;
 
 namespace QuestPDF.Previewer
@@ -27,7 +25,7 @@ namespace QuestPDF.Previewer
             _previewHost = this.FindControl<PreviewerControl>("PreviewerSurface");
 
             this.FindControl<Button>("GeneratePdf")
-                .Click += (_, __) => _ = PreviewerUtils.SavePdfWithDialog(Document, this);
+                .Click += (_, _) => _ = PreviewerUtils.SavePdfWithDialog(Document, this);
 
             DocumentProperty.Changed.Subscribe(v => _previewHost.Document = v.NewValue.Value);
             HotReloadManager.Register(InvalidatePreview);

QuestPDF.Previewer/SkCustomDrawOperation.cs

@@ -6,24 +6,22 @@ using SkiaSharp;
 
 namespace QuestPDF.Previewer
 {
-    internal class SkPictureRenderOperation : ICustomDrawOperation
+    internal sealed class SkCustomDrawOperation : ICustomDrawOperation
     {
-        public SKPicture? Picture { get; }
+        private readonly Action<SKCanvas> _renderFunc;
         public Rect Bounds { get; }
 
-        public SkPictureRenderOperation(SKPicture picture, Rect bounds)
+        public SkCustomDrawOperation(Rect bounds, Action<SKCanvas> renderFunc)
         {
-            Picture = picture;
             Bounds = bounds;
+            _renderFunc = renderFunc;
         }
 
         public void Dispose() { }
-
         public bool Equals(ICustomDrawOperation? other)
         {
             return false;
         }
-
         public bool HitTest(Point p)
         {
             return false;
@@ -31,14 +29,11 @@ namespace QuestPDF.Previewer
 
         public void Render(IDrawingContextImpl context)
         {
-            if (Picture == null)
-                return;
-
             var canvas = (context as ISkiaDrawingContextImpl)?.SkCanvas;
             if (canvas == null)
                 throw new InvalidOperationException($"Context needs to be ISkiaDrawingContextImpl but got {nameof(context)}");
 
-            canvas.DrawPicture(Picture);
+            _renderFunc(canvas);
         }
     }
 }