From 78fe25407ddbfe20a34e71dbdb2111bb028907fd Mon Sep 17 00:00:00 2001
From: Julien Lebosquain <julien@lebosquain.net>
Date: Fri, 23 Aug 2024 16:47:44 +0200
Subject: [PATCH] Fixes stuck modifier keys on focus lost on macOS

---
 native/Avalonia.Native/src/OSX/AvnView.h    | 1 +
 native/Avalonia.Native/src/OSX/AvnView.mm   | 5 +++++
 native/Avalonia.Native/src/OSX/AvnWindow.mm | 5 ++++-
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/native/Avalonia.Native/src/OSX/AvnView.h b/native/Avalonia.Native/src/OSX/AvnView.h
index 75a5e98ed46..030330c9081 100644
--- a/native/Avalonia.Native/src/OSX/AvnView.h
+++ b/native/Avalonia.Native/src/OSX/AvnView.h
@@ -18,6 +18,7 @@
 -(NSEvent* _Nonnull) lastMouseDownEvent;
 -(AvnPoint) translateLocalPoint:(AvnPoint)pt;
 -(void) onClosed;
+-(void) setModifiers:(NSEventModifierFlags)modifierFlags;
 
 -(AvnPlatformResizeReason) getResizeReason;
 -(void) setResizeReason:(AvnPlatformResizeReason)reason;
diff --git a/native/Avalonia.Native/src/OSX/AvnView.mm b/native/Avalonia.Native/src/OSX/AvnView.mm
index 8c38b1cf2d9..664ac81e2f3 100644
--- a/native/Avalonia.Native/src/OSX/AvnView.mm
+++ b/native/Avalonia.Native/src/OSX/AvnView.mm
@@ -480,6 +480,11 @@ - (void) keyboardEvent: (NSEvent *) event withType: (AvnRawKeyEventType)type
     _parent->TopLevelEvents->RawKeyEvent(type, timestamp, modifiers, key, physicalKey, keySymbolUtf8);
 }
 
+- (void)setModifiers:(NSEventModifierFlags)modifierFlags
+{
+    _modifierState = [self getModifiers:modifierFlags];
+}
+
 - (void)flagsChanged:(NSEvent *)event
 {
     auto newModifierState = [self getModifiers:[event modifierFlags]];
diff --git a/native/Avalonia.Native/src/OSX/AvnWindow.mm b/native/Avalonia.Native/src/OSX/AvnWindow.mm
index 9b92dba5239..2f603f0cade 100644
--- a/native/Avalonia.Native/src/OSX/AvnWindow.mm
+++ b/native/Avalonia.Native/src/OSX/AvnWindow.mm
@@ -298,7 +298,10 @@ - (void)windowDidBecomeKey:(NSNotification *_Nonnull)notification
 {
     if (_parent == nullptr)
         return;
-    
+
+    if (_parent->View != nullptr)
+        [_parent->View setModifiers:NSEvent.modifierFlags];
+
     _parent->BringToFront();
     
     dispatch_async(dispatch_get_main_queue(), ^{