From e36bb3d10fc199342dd833518e9cd6970c4e7431 Mon Sep 17 00:00:00 2001
From: Nick Randolph <nick@builttoroam.com>
Date: Wed, 26 Oct 2022 12:40:16 +1100
Subject: [PATCH] feat: Moving navigation to background thread

---
 src/Uno.Extensions.Navigation.UI/Navigator.cs |  1 +
 .../Navigators/PanelVisiblityNavigator.cs     | 27 ++++++++++---------
 .../NavigationRequest.cs                      |  4 ++-
 3 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/src/Uno.Extensions.Navigation.UI/Navigator.cs b/src/Uno.Extensions.Navigation.UI/Navigator.cs
index a6f51a32bb..a81ef9e011 100644
--- a/src/Uno.Extensions.Navigation.UI/Navigator.cs
+++ b/src/Uno.Extensions.Navigation.UI/Navigator.cs
@@ -49,6 +49,7 @@ protected Navigator(
 			{
 				if (Logger.IsEnabled(LogLevel.Information)) Logger.LogInformationMessage($"Starting Navigation - Navigator: {this.GetType().Name} Request: {request.Route}");
 				request = request with { Source = this };
+				return await Task.Run(() => NavigateAsync(request));
 			}
 
 
diff --git a/src/Uno.Extensions.Navigation.UI/Navigators/PanelVisiblityNavigator.cs b/src/Uno.Extensions.Navigation.UI/Navigators/PanelVisiblityNavigator.cs
index d74c288d7b..4d13c908c5 100644
--- a/src/Uno.Extensions.Navigation.UI/Navigators/PanelVisiblityNavigator.cs
+++ b/src/Uno.Extensions.Navigation.UI/Navigators/PanelVisiblityNavigator.cs
@@ -99,27 +99,28 @@ protected override async Task<bool> RegionCanNavigate(Route route, RouteInfo? ro
 		return path;
 	}
 
-	protected override Task PostNavigateAsync()
+	protected override async Task PostNavigateAsync()
 	{
 		if (Control is not null)
 		{
-			foreach (var child in Control.Children.OfType<FrameworkElement>())
+			await Dispatcher.ExecuteAsync(async cancellation =>
 			{
-				if(child == CurrentlyVisibleControl)
+				foreach (var child in Control.Children.OfType<FrameworkElement>())
 				{
-					child.Opacity = 1;
-					child.Visibility = Visibility.Visible;
-				}
-				else
-				{
-					child.Opacity = 0;
-					child.Visibility = Visibility.Collapsed;
+					if (child == CurrentlyVisibleControl)
+					{
+						child.Opacity = 1;
+						child.Visibility = Visibility.Visible;
+					}
+					else
+					{
+						child.Opacity = 0;
+						child.Visibility = Visibility.Collapsed;
 
+					}
 				}
-			}
+			});
 		}
-
-		return Task.CompletedTask;
 	}
 
 	private FrameworkElement? FindByPath(string? path)
diff --git a/src/Uno.Extensions.Navigation/NavigationRequest.cs b/src/Uno.Extensions.Navigation/NavigationRequest.cs
index 068de8814f..ace7967a9c 100644
--- a/src/Uno.Extensions.Navigation/NavigationRequest.cs
+++ b/src/Uno.Extensions.Navigation/NavigationRequest.cs
@@ -1,9 +1,11 @@
 namespace Uno.Extensions.Navigation;
 
 #pragma warning disable SA1313 // Parameter names should begin with lower-case letter
-public record NavigationRequest(object Sender, Route Route, CancellationToken? Cancellation = default, Type? Result = null, INavigator? Source = null)
+public record NavigationRequest(object Sender, Route Route, CancellationToken? Cancellation = default, Type? Result = null)
 #pragma warning restore SA1313 // Parameter names should begin with lower-case letter
 {
+	internal INavigator? Source { get; init; }
+
 	public override string ToString() => $"Request [Sender: {Sender.GetType().Name}, Route:{Route}, Result: {Result?.Name ?? "N/A"}]";
 
 	internal virtual IResponseNavigator? GetResponseNavigator(IResponseNavigatorFactory responseFactory, INavigator navigator) => default;