QML: Allow singletons to be created with a factory function

This is in line with what we do on qmlRegisterSingletonType(), and it
allows us to return singleton objects created independently of the
instantiation mechanism.

Change-Id: Ia6a077f5d22241593acd8cc87b3f65ae20f95667
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Maximilian Goldstein <max.goldstein@qt.io>

1 files changed, 8 insertions, 6 deletions

diff --git a/src/qml/doc/src/qmlfunctions.qdoc b/src/qml/doc/src/qmlfunctions.qdoc
index caca58f34a..25cdd8142a 100644
--- a/src/qml/doc/src/qmlfunctions.qdoc
+++ b/src/qml/doc/src/qmlfunctions.qdoc
@@ -163,12 +163,14 @@
   Declares the enclosing type to be a singleton in QML. This only takes effect
   if the type is available in QML, by having a \l QML_ELEMENT or
   \l QML_NAMED_ELEMENT() macro. By default, each QQmlEngine will try to create a
-  singleton instance using the type's default constructor when the type is first
-  accessed. If there is no default constructor the singleton is initially
-  inaccessible. This behavior can be overridden by calling
-  \l qmlRegisterSingletonType() with a specific factory function or
-  \l qmlRegisterSingletonInstance() with a specific instance for the same class
-  and the same type namespace and version.
+  singleton instance using either the type's default constructor or a static
+  factory function of the signature \a{T *create(QQmlEngine *, QJSEngine *)}
+  when the type is first accessed. If both do exist and are accessible, the
+  default constructor is preferred. If there is no default constructor and no
+  factory function the singleton is initially inaccessible. This behavior can be
+  overridden by calling \l qmlRegisterSingletonType() with a specific (external)
+  factory function or \l qmlRegisterSingletonInstance() with a specific instance
+  for the same class and the same type namespace and version.
 
   \sa QML_ELEMENT, QML_NAMED_ELEMENT(), qmlRegisterSingletonInstance().
 */