From aeee9d165fb8e7414bfe1b21f261639ad7b01b2c Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Thu, 20 Jan 2022 10:35:07 +0000
Subject: [PATCH] add TryShutdown method.

---
 .../ClassicDesktopStyleApplicationLifetime.cs     | 15 +++++++++++----
 .../IClassicDesktopStyleApplicationLifetime.cs    |  6 ++++++
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/Avalonia.Controls/ApplicationLifetimes/ClassicDesktopStyleApplicationLifetime.cs b/src/Avalonia.Controls/ApplicationLifetimes/ClassicDesktopStyleApplicationLifetime.cs
index 536e39cc34..8006149ee9 100644
--- a/src/Avalonia.Controls/ApplicationLifetimes/ClassicDesktopStyleApplicationLifetime.cs
+++ b/src/Avalonia.Controls/ApplicationLifetimes/ClassicDesktopStyleApplicationLifetime.cs
@@ -83,7 +83,12 @@ namespace Avalonia.Controls.ApplicationLifetimes
 
         public void Shutdown(int exitCode = 0)
         {
-            DoShutdown(new ShutdownRequestedEventArgs(), exitCode);
+            DoShutdown(new ShutdownRequestedEventArgs(), true, exitCode);
+        }
+
+        public bool TryShutdown(int exitCode = 0)
+        {
+            return DoShutdown(new ShutdownRequestedEventArgs(), false, exitCode);
         }
         
         public int Start(string[] args)
@@ -126,12 +131,12 @@ namespace Avalonia.Controls.ApplicationLifetimes
                 _activeLifetime = null;
         }
 
-        private void DoShutdown(ShutdownRequestedEventArgs e, int exitCode = 0)
+        private bool DoShutdown(ShutdownRequestedEventArgs e, bool force = false, int exitCode = 0)
         {
             ShutdownRequested?.Invoke(this, e);
 
             if (e.Cancel)
-                return;
+                false;
 
             if (_isShuttingDown)
                 throw new InvalidOperationException("Application is already shutting down.");
@@ -155,7 +160,7 @@ namespace Avalonia.Controls.ApplicationLifetimes
                 if (Windows.Count > 0)
                 {
                     e.Cancel = true;
-                    return;
+                    return false;
                 }
 
                 var e = new ControlledApplicationLifetimeExitEventArgs(exitCode);
@@ -168,6 +173,8 @@ namespace Avalonia.Controls.ApplicationLifetimes
                 _cts = null;
                 _isShuttingDown = false;
             }
+
+            return true;
         }
         
         private void OnShutdownRequested(object sender, ShutdownRequestedEventArgs e) => DoShutdown(e);
diff --git a/src/Avalonia.Controls/ApplicationLifetimes/IClassicDesktopStyleApplicationLifetime.cs b/src/Avalonia.Controls/ApplicationLifetimes/IClassicDesktopStyleApplicationLifetime.cs
index a70d5dd2f1..a83229b732 100644
--- a/src/Avalonia.Controls/ApplicationLifetimes/IClassicDesktopStyleApplicationLifetime.cs
+++ b/src/Avalonia.Controls/ApplicationLifetimes/IClassicDesktopStyleApplicationLifetime.cs
@@ -9,6 +9,12 @@ namespace Avalonia.Controls.ApplicationLifetimes
     /// </summary>
     public interface IClassicDesktopStyleApplicationLifetime : IControlledApplicationLifetime
     {
+        /// <summary>
+        /// Tries to Shutdown the application. <see cref="ShutdownRequested" /> event can be used to cancel the shutdown.
+        /// </summary>
+        /// <param name="exitCode">An integer exit code for an application. The default exit code is 0.</param>
+        bool TryShutdown(int exitCode = 0);
+
         /// <summary>
         /// Gets the arguments passed to the
         /// <see cref="ClassicDesktopStyleApplicationLifetimeExtensions.StartWithClassicDesktopLifetime{T}(T, string[], ShutdownMode)"/>