1 files changed, 31 insertions, 0 deletions
diff --git a/src/corelib/kernel/qcore_mac_objc.mm b/src/corelib/kernel/qcore_mac_objc.mm
index 6b51eb65d9..15b69acbd4 100644
--- a/src/corelib/kernel/qcore_mac_objc.mm
+++ b/src/corelib/kernel/qcore_mac_objc.mm
@@ -514,5 +514,36 @@ Q_CONSTRUCTOR_FUNCTION(qt_apple_check_os_version);
 
 // -------------------------------------------------------------------------
 
+void QMacKeyValueObserver::addObserver()
+{
+    [object addObserver:observer forKeyPath:keyPath
+        options:NSKeyValueObservingOptionNew context:callback.get()];
+}
+
+void QMacKeyValueObserver::removeObserver() {
+    if (object)
+        [object removeObserver:observer forKeyPath:keyPath context:callback.get()];
+    object = nil;
+}
+
+KeyValueObserver *QMacKeyValueObserver::observer = [[KeyValueObserver alloc] init];
+
+QT_END_NAMESPACE
+@implementation KeyValueObserver
+- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object
+        change:(NSDictionary<NSKeyValueChangeKey, id> *)change context:(void *)context
+{
+    Q_UNUSED(keyPath);
+    Q_UNUSED(object);
+    Q_UNUSED(change);
+
+    (*reinterpret_cast<QMacKeyValueObserver::Callback*>(context))();
+}
+@end
+QT_BEGIN_NAMESPACE
+
+// -------------------------------------------------------------------------
+
+
 QT_END_NAMESPACE