3 files changed, 12 insertions, 3 deletions
diff --git a/src/plugins/platforms/cocoa/qnswindow.h b/src/plugins/platforms/cocoa/qnswindow.h
index f69e809133..8f842eba85 100644
--- a/src/plugins/platforms/cocoa/qnswindow.h
+++ b/src/plugins/platforms/cocoa/qnswindow.h
@@ -36,6 +36,8 @@ QT_FORWARD_DECLARE_CLASS(QCocoaWindow)
 
 typedef NSWindow<QNSWindowProtocol> QCocoaNSWindow;
 
+QCocoaNSWindow *qnswindow_cast(NSWindow *window);
+
 #else
 class QCocoaNSWindow;
 #endif // __OBJC__
diff --git a/src/plugins/platforms/cocoa/qnswindow.mm b/src/plugins/platforms/cocoa/qnswindow.mm
index 6244d5d129..da3979882a 100644
--- a/src/plugins/platforms/cocoa/qnswindow.mm
+++ b/src/plugins/platforms/cocoa/qnswindow.mm
@@ -58,6 +58,15 @@ static bool isMouseEvent(NSEvent *ev)
 }
 @end
 
+
+NSWindow<QNSWindowProtocol> *qnswindow_cast(NSWindow *window)
+{
+    if ([window conformsToProtocol:@protocol(QNSWindowProtocol)])
+        return static_cast<QCocoaNSWindow *>(window);
+    else
+        return nil;
+}
+
 @implementation QNSWindow
 #define QNSWINDOW_PROTOCOL_IMPLMENTATION 1
 #include "qnswindow.mm"
diff --git a/src/plugins/platforms/cocoa/qnswindowdelegate.mm b/src/plugins/platforms/cocoa/qnswindowdelegate.mm
index 2d90fbf544..1db7772771 100644
--- a/src/plugins/platforms/cocoa/qnswindowdelegate.mm
+++ b/src/plugins/platforms/cocoa/qnswindowdelegate.mm
@@ -23,9 +23,7 @@ static inline bool isWhiteSpace(const QString &s)
 
 static QCocoaWindow *toPlatformWindow(NSWindow *window)
 {
-    if ([window conformsToProtocol:@protocol(QNSWindowProtocol)])
-        return static_cast<QCocoaNSWindow *>(window).platformWindow;
-    return nullptr;
+    return qnswindow_cast(window).platformWindow;
 }
 
 @implementation QNSWindowDelegate