<![CDATA[Can't store a QPointer into a QVariant]]>Hello,

I'm trying to store a Pointer to a QVector<Album*> into a QAction, but I can't convert it to QVariant.

I have
@
QVector<Album*>* data;
action->setData(QVariant::fromValue(QPointer<QVector<Album*> >(data)));
@

and it fails with following error:

In instantiation of 'QPointer<T>::QPointer(T*) [with T = QVectorDigikam::Album*]':
/media/LinuxHDD/slavik/digikam-software-compilation/core/digikam/tags/tagmodificationhelper.cpp:98:72: required from here
/usr/include/qt4/QtCore/qpointer.h:59:32: error: cannot convert 'QVectorDigikam::Album*' to 'QObject' in initialization
inline QPointer(T *p) : o(p)

I don't know how to deal with this... QPointer<QVector> works fine , but QPointer<QVector<Album*> > won't...

Thank you!

]]>https://forum.qt.io/topic/29629/can-t-store-a-qpointer-into-a-qvariantRSS for NodeWed, 23 Sep 2026 09:15:52 GMTFri, 19 Jul 2013 11:56:13 GMT60<![CDATA[Reply to Can't store a QPointer into a QVariant on Fri, 19 Jul 2013 20:44:46 GMT]]>I was able to pass it with:

Q_DECLARE_METACALL(QList<Album*>)

Basically, I try to implement item deletion in a context menu. Originally, tree was single selection and a pointer to item was encoded into QAction's data. Now, I'm trying to implement multiple selection and deletion is the first one to change...

The design of KDE's digiKam is complicated and I can't have direct access to treeView to ask for selected items. Instead, I should stick to this design, but I accept all suggestions :)

]]>https://forum.qt.io/post/187206https://forum.qt.io/post/187206Fri, 19 Jul 2013 20:44:46 GMT<![CDATA[Reply to Can't store a QPointer into a QVariant on Fri, 19 Jul 2013 20:08:26 GMT]]>You can use quintptr but are you sure that having that in the action is the best design ?

]]>https://forum.qt.io/post/187193https://forum.qt.io/post/187193Fri, 19 Jul 2013 20:08:26 GMT<![CDATA[Reply to Can't store a QPointer into a QVariant on Fri, 19 Jul 2013 19:30:33 GMT]]>So a container won't work...

Any idea of how to pass that pointer through QAction?

]]>https://forum.qt.io/post/187187https://forum.qt.io/post/187187Fri, 19 Jul 2013 19:30:33 GMT<![CDATA[Reply to Can't store a QPointer into a QVariant on Fri, 19 Jul 2013 14:11:27 GMT]]>QVector does not subclass QObject, so it is not a QObject.

]]>https://forum.qt.io/post/187161https://forum.qt.io/post/187161Fri, 19 Jul 2013 14:11:27 GMT<![CDATA[Reply to Can't store a QPointer into a QVariant on Fri, 19 Jul 2013 14:03:40 GMT]]>No, QVector is not a QObject, it's a templated container (you can verify in the source code).

]]>https://forum.qt.io/post/187158https://forum.qt.io/post/187158Fri, 19 Jul 2013 14:03:40 GMT<![CDATA[Reply to Can't store a QPointer into a QVariant on Fri, 19 Jul 2013 13:57:02 GMT]]>But, QVector is a QObject, I only added a template argument to it...

I can't use QPointer<QVector>(data) because of template mismatch.

]]>https://forum.qt.io/post/187157https://forum.qt.io/post/187157Fri, 19 Jul 2013 13:57:02 GMT<![CDATA[Reply to Can't store a QPointer into a QVariant on Fri, 19 Jul 2013 13:47:08 GMT]]>Hi,

QPointer must be used with QObject, have a look at "this":http://qt-project.org/doc/qt-4.8/qpointer.html#details

]]>https://forum.qt.io/post/187154https://forum.qt.io/post/187154Fri, 19 Jul 2013 13:47:08 GMT