Q(Untyped)Bindable: add takeBinding method

We missed takeBinding as a supported operation on Q(Untyped)Bindable.
To avoid adding version checks to code dealing with QBindableInterface,
we simply synthesize takeBinding as a combination of binding to retrieve
the binding and setBinding with a default-constructed
QUntypedPropertyBinding.

Change-Id: I43803a0dfe210353d0235f0373d2257f75ffe534
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

2 files changed, 42 insertions, 1 deletions

diff --git a/src/corelib/kernel/qproperty.cpp b/src/corelib/kernel/qproperty.cpp
index 342a3d34eb..90df159e88 100644
--- a/src/corelib/kernel/qproperty.cpp
+++ b/src/corelib/kernel/qproperty.cpp
@@ -788,10 +788,19 @@ QString QPropertyBindingError::description() const
 */
 
 /*!
+  \fn QUntypedPropertyBinding QUntypedBindable::takeBinding()
+
+  Removes the currently set binding from the property and returns it.
+  Returns a default-constructed QUntypedPropertyBinding if no binding is set.
+
+  \since 6.1
+*/
+
+/*!
   \fn bool QUntypedBindable::setBinding(const QUntypedPropertyBinding &binding)
 
   Sets the underlying property's binding to \a binding. This does not have any effect
-  if the QUntypedBindable is read-only, invalid or if \a binding's type does match the
+  if the QUntypedBindable is read-only, null or if \a binding's type does match the
   underlying property's type.
 
   \sa QUntypedPropertyBinding::valueMetaType()
@@ -842,6 +851,16 @@ QString QPropertyBindingError::description() const
 */
 
 /*!
+  \fn template <typename T> QPropertyBinding<T> QBindable<T>::takeBinding()
+
+   Removes the currently set binding of the underlying property and returns it.
+   If the property does not have a binding, the returned \c QPropertyBinding<T> will be invalid.
+
+   \sa setBinding, getBinding, QPropertyBinding<T>::isValid(), hasBinding
+*/
+
+
+/*!
   \fn template <typename T> void QBindable<T>::setBinding(const QPropertyBinding<T> &binding)
 
    Sets the underlying property's binding to \a binding. Does nothing if the QBindable is
diff --git a/src/corelib/kernel/qproperty.h b/src/corelib/kernel/qproperty.h
index f853eb8634..750d75c4a7 100644
--- a/src/corelib/kernel/qproperty.h
+++ b/src/corelib/kernel/qproperty.h
@@ -581,6 +581,22 @@ public:
     {
         return iface ? iface->makeBinding(data, location) : QUntypedPropertyBinding();
     }
+
+    QUntypedPropertyBinding takeBinding()
+    {
+        if (!iface)
+            return QUntypedPropertyBinding {};
+        // We do not have a dedicated takeBinding function pointer in the interface
+        // therefore we synthesize takeBinding by retrieving the binding with binding
+        // and calling setBinding with a default constructed QUntypedPropertyBinding
+        // afterwards.
+        if (!(iface->getBinding && iface->setBinding))
+            return QUntypedPropertyBinding {};
+        QUntypedPropertyBinding binding = iface->getBinding(data);
+        iface->setBinding(data, QUntypedPropertyBinding{});
+        return binding;
+    }
+
     void observe(QPropertyObserver *observer)
     {
         if (iface)
@@ -650,6 +666,12 @@ public:
     {
         return static_cast<QPropertyBinding<T> &&>(QUntypedBindable::binding());
     }
+
+    QPropertyBinding<T> takeBinding()
+    {
+        return static_cast<QPropertyBinding<T> &&>(QUntypedBindable::takeBinding());
+    }
+
     using QUntypedBindable::setBinding;
     QPropertyBinding<T> setBinding(const QPropertyBinding<T> &binding)
     {