QNotifiedProperty: pass old value to callback if requested

Check at compile time whether the static callback takes an argument
(which has to be of the same time as the type of the property). If so,
retrieve the old value and pass it to the callback.

Change-Id: Ib1c4c9e05b826b6be492b03f66fa72ad015963ee
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/corelib/kernel/qpropertyprivate.h b/src/corelib/kernel/qpropertyprivate.h
index 7a2c6a5b77..43318f25c0 100644
--- a/src/corelib/kernel/qpropertyprivate.h
+++ b/src/corelib/kernel/qpropertyprivate.h
@@ -84,7 +84,7 @@ public:
 
     QUntypedPropertyBinding setBinding(const QUntypedPropertyBinding &newBinding,
                                        void *propertyDataPtr, void *staticObserver = nullptr,
-                                       void (*staticObserverCallback)(void*) = nullptr);
+                                       void (*staticObserverCallback)(void *, void *) = nullptr);
     QPropertyBindingPrivate *binding();
 
     void evaluateIfDirty();