From be73db7bebc51232d4168a7f660cf0aff5ab9f0c Mon Sep 17 00:00:00 2001
From: Nikita Tsukanov <keks9n@gmail.com>
Date: Mon, 29 Jun 2020 17:24:56 +0300
Subject: [PATCH] Dispose the renderer before detaching visuals from the tree
 (perf)

See https://github.com/AvaloniaUI/Avalonia/issues/3622
---
 src/Avalonia.Controls/TopLevel.cs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/Avalonia.Controls/TopLevel.cs b/src/Avalonia.Controls/TopLevel.cs
index 6c3a2d4a03..f058942116 100644
--- a/src/Avalonia.Controls/TopLevel.cs
+++ b/src/Avalonia.Controls/TopLevel.cs
@@ -340,6 +340,9 @@ namespace Avalonia.Controls
                 _globalStyles.GlobalStylesRemoved -= ((IStyleHost)this).StylesRemoved;
             }
 
+            Renderer?.Dispose();
+            Renderer = null;
+            
             var logicalArgs = new LogicalTreeAttachmentEventArgs(this, this, null);
             ((ILogical)this).NotifyDetachedFromLogicalTree(logicalArgs);
 
@@ -349,8 +352,7 @@ namespace Avalonia.Controls
             (this as IInputRoot).MouseDevice?.TopLevelClosed(this);
             PlatformImpl = null;
             OnClosed(EventArgs.Empty);
-            Renderer?.Dispose();
-            Renderer = null;
+
             LayoutManager?.Dispose();
         }