Core/IOBluetooth - minor refactoring in RAII classes

To prepare a switch from QScoped/QShared specializations in ObjC-RAII classes.
Since StrongReference will become a parent for ObjCStrongReference, add
'take'-like functionality we have for free from QSharedPointer (used when
we relegate the ownership and pass it to IOBluetooth)

Change-Id: Iab7758e6c51c339bf7afc49007d921380d38ba51
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

2 files changed, 16 insertions, 7 deletions

diff --git a/src/bluetooth/darwin/btraii.mm b/src/bluetooth/darwin/btraii.mm
index a1bf2a8d..486c3c14 100644
--- a/src/bluetooth/darwin/btraii.mm
+++ b/src/bluetooth/darwin/btraii.mm
@@ -52,13 +52,14 @@ namespace DarwinBluetooth {
 StrongReference::StrongReference(void *object, RetainPolicy policy)
     : objCInstance(object)
 {
-    if (policy == RetainPolicy::doInitialRetain)
+    if (objCInstance && policy == RetainPolicy::doInitialRetain)
         objCInstance = [getAs<NSObject>() retain];
 }
 
 StrongReference::StrongReference(const StrongReference &other)
 {
-    objCInstance = [other.getAs<NSObject>() retain];
+    if ((objCInstance = other.getAs<NSObject>()))
+        objCInstance = [other.getAs<NSObject>() retain];
 }
 
 StrongReference::StrongReference(StrongReference &&other)
@@ -84,9 +85,18 @@ StrongReference &StrongReference::operator = (const StrongReference &other) noex
 StrongReference &StrongReference::operator = (StrongReference &&other) noexcept
 {
     swap(other);
+
     return *this;
 }
 
+void *StrongReference::release()
+{
+    void *released = objCInstance;
+    objCInstance = nullptr;
+
+    return released;
+}
+
 void StrongReference::reset()
 {
     [getAs<NSObject>() release];
@@ -98,11 +108,8 @@ void StrongReference::reset(void *obj, RetainPolicy policy)
     [getAs<NSObject>() release];
     objCInstance = obj;
 
-    if (policy == RetainPolicy::doInitialRetain) {
-        auto newInstance = static_cast<NSObject *>(obj);
-        Q_ASSERT(newInstance);
-        objCInstance = [newInstance retain];
-    }
+    if (objCInstance && policy == RetainPolicy::doInitialRetain)
+        objCInstance = [getAs<NSObject>() retain];
 }
 
 } // namespace DarwinBluetooth
diff --git a/src/bluetooth/darwin/btraii_p.h b/src/bluetooth/darwin/btraii_p.h
index 6053d63b..c7a159cb 100644
--- a/src/bluetooth/darwin/btraii_p.h
+++ b/src/bluetooth/darwin/btraii_p.h
@@ -98,6 +98,8 @@ public:
         std::swap(objCInstance, other.objCInstance);
     }
 
+    void *release();
+
     void reset();
     void reset(void *newInstance, RetainPolicy policy);