From 92327dcc0d348c2edee38acfb35143d18153e9e1 Mon Sep 17 00:00:00 2001
From: Michael Bucari-Tovo <mbucari1@gmail.com>
Date: Thu, 28 Jul 2022 10:40:39 -0600
Subject: [PATCH] Add synchronous thread extensions

---
 .../LibationAvalonia/AvaloniaThreadUtils.cs   | 46 +++++++++++++++++++
 Source/LibationAvalonia/AvaloniaUtils.cs      |  7 +--
 Source/LibationAvalonia/MessageBox.cs         |  8 ++--
 3 files changed, 51 insertions(+), 10 deletions(-)
 create mode 100644 Source/LibationAvalonia/AvaloniaThreadUtils.cs

diff --git a/Source/LibationAvalonia/AvaloniaThreadUtils.cs b/Source/LibationAvalonia/AvaloniaThreadUtils.cs
new file mode 100644
index 00000000..b14f6ec0
--- /dev/null
+++ b/Source/LibationAvalonia/AvaloniaThreadUtils.cs
@@ -0,0 +1,46 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Avalonia.Threading
+{
+	internal static class AvaloniaThreadUtils
+	{
+		public static TResult Invoke<TResult>(this Dispatcher dispatcher, Func<TResult> function, DispatcherPriority dispatcherPriority = DispatcherPriority.Normal)
+		{
+			using var source = new CancellationTokenSource();
+			var task = dispatcher.InvokeAsync(function, dispatcherPriority);
+			task.ContinueWith(t => source.Cancel(), TaskScheduler.FromCurrentSynchronizationContext());
+			dispatcher.MainLoop(source.Token);
+			return task.Result;
+		}
+
+		public static void Invoke(this Dispatcher dispatcher, Action action, DispatcherPriority dispatcherPriority = DispatcherPriority.Normal)
+		{
+			using var source = new CancellationTokenSource();
+			var task = dispatcher.InvokeAsync(action, dispatcherPriority);
+			task.ContinueWith(t => source.Cancel(), TaskScheduler.FromCurrentSynchronizationContext());
+			Dispatcher.UIThread.MainLoop(source.Token);
+		}
+
+		public static T WaitOnUIAndGetResult<T>(this Task<T> task)
+			=> WaitOnDispatcherAndGetResult(task, Dispatcher.UIThread);
+
+		public static T WaitOnDispatcherAndGetResult<T>(this Task<T> task, Dispatcher dispatcher)
+		{
+			using var source = new CancellationTokenSource();
+			task.ContinueWith(t => source.Cancel(), TaskScheduler.FromCurrentSynchronizationContext());
+			dispatcher.MainLoop(source.Token);
+			return task.Result;
+		}
+
+		public static void WaitOnUI(this Task task)
+			=> WaitOnDispatcher(task, Dispatcher.UIThread);
+		public static void WaitOnDispatcher(this Task task, Dispatcher dispatcher)
+		{
+			using var source = new CancellationTokenSource();
+			task.ContinueWith(t => source.Cancel(), TaskScheduler.FromCurrentSynchronizationContext());
+			dispatcher.MainLoop(source.Token);
+		}
+	}
+}
diff --git a/Source/LibationAvalonia/AvaloniaUtils.cs b/Source/LibationAvalonia/AvaloniaUtils.cs
index 7ade8b9a..6efc93a5 100644
--- a/Source/LibationAvalonia/AvaloniaUtils.cs
+++ b/Source/LibationAvalonia/AvaloniaUtils.cs
@@ -1,4 +1,5 @@
 using Avalonia.Media;
+using Avalonia.Threading;
 using System;
 using System.Threading;
 using System.Threading.Tasks;
@@ -18,11 +19,7 @@ namespace LibationAvalonia
 
 		public static T ShowDialogSynchronously<T>(this Avalonia.Controls.Window window, Avalonia.Controls.Window owner)
 		{
-			using var source = new CancellationTokenSource();
-			var dialogTask = window.ShowDialog<T>(owner);
-			dialogTask.ContinueWith(t => source.Cancel(), TaskScheduler.FromCurrentSynchronizationContext());
-			Avalonia.Threading.Dispatcher.UIThread.MainLoop(source.Token);
-			return dialogTask.Result;
+			return window.ShowDialog<T>(owner).WaitOnUIAndGetResult();
 		}
 	}
 }
diff --git a/Source/LibationAvalonia/MessageBox.cs b/Source/LibationAvalonia/MessageBox.cs
index 39d4ac66..3ad00a8f 100644
--- a/Source/LibationAvalonia/MessageBox.cs
+++ b/Source/LibationAvalonia/MessageBox.cs
@@ -10,6 +10,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using System.Threading;
+using Avalonia.Threading;
 
 namespace LibationAvalonia
 {
@@ -150,12 +151,9 @@ Libation.
 
 		private static DialogResult ShowCoreAsync(Window owner, string message, string caption, MessageBoxButtons buttons, MessageBoxIcon icon, MessageBoxDefaultButton defaultButton, bool saveAndRestorePosition = true)
 		{
-			using var source = new CancellationTokenSource();
-			var dialogTask = Avalonia.Threading.Dispatcher.UIThread.InvokeAsync(() => CreateMessageBox(owner, message, caption, buttons, icon, defaultButton, saveAndRestorePosition));
-			dialogTask.ContinueWith(t => source.Cancel(), TaskScheduler.FromCurrentSynchronizationContext());
-			Avalonia.Threading.Dispatcher.UIThread.MainLoop(source.Token);
+			var dialogTask = Dispatcher.UIThread.Invoke(() => CreateMessageBox(owner, message, caption, buttons, icon, defaultButton, saveAndRestorePosition));
 
-			return DisplayWindow(dialogTask.Result, owner);
+			return DisplayWindow(dialogTask, owner);
 		}
 
 		private static MessageBoxWindow CreateMessageBox(Window owner, string message, string caption, MessageBoxButtons buttons, MessageBoxIcon icon, MessageBoxDefaultButton defaultButton, bool saveAndRestorePosition = true)