[PyQt] Construct QVariant from object of user type
arve.knudsen at gmail.com
Fri Apr 18 12:36:46 BST 2008
On 4/17/08, Arve Knudsen <arve.knudsen at gmail.com> wrote:
> On 4/17/08, Matt Newell <newellm at blur.com> wrote:
> > On Wednesday 16 April 2008 14:18:26 Arve Knudsen wrote:
> > > On Wed, Apr 16, 2008 at 11:33 AM, Phil Thompson
> > >
> > > <phil at riverbankcomputing.co.uk> wrote:
> > > > On Wednesday 16 April 2008, Arve Knudsen wrote:
> > > > > Phil, any comment on this?
> > > > >
> > > > > Thanks,
> > > > > Arve
> > > >
> > > > Unless you can use the ctor that takes a void* I don't see how you can
> > > > expect to extend the functionality of a C++ class from Python.
> > >
> > > How am I supposed to use the QVariant(int typeOrUserType, const void*
> > > copy) constructor from Python? The documentation refers to
> > > sip.voidptr, which I know nothing about, and to use qVariantFromValue
> > > which isn't defined.
> > >
> > > I need to store objects of a custom class in QVariants, with a certain
> > > type code (QVariant::Type). The reason I need to do this is that
> > > QItemEditorFactory is parameterized on QVariant::Type.
> > >
> > > Arve
> > If you look at qmetatype.h, you'll see that it should be possible to create a
> > mechanism to register custom python classes as QVariant types. You just need
> > to implement Constructor/Destructor methods that call Py_INCREF/Py_DECREF.
> > Then for each custom python type call QMetaType::registerType(...). This
> > would need to be implemented in c++ with a python interface.
> > You could then write a custom QVariant constructor that detects if the python
> > object's type is registered, and automatically call the QVariant(int
> > type,void*) ctor, or throws an exception for non-registered types.
> So I would *have to* do this in C++? Ugh.
Phil: Can you confirm that I have to do this via C++?
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