On Thu, 08 Mar 2012 08:35:30 +0100, Benjamin Kloster <benjamin.klos...@videlco.eu> wrote: > Hi everyone, > since my use case is a rather long-winded description of my predicament,
> first my question: > > Are there API functions of sip that I can use to convert a PyObject* to > a QVariant with the appropriate type and the other way around? No. > Now why I could really use such functions: For our application, I've > written a small C++ library that serializes QVariants along with their > type. I used sip to generate Python bindings to that library. Now I'd > like to serialize Python types that aren't natively supported by > QVariant, particularly instances of decimal.Decimal, tuples and maybe > sets. All those are boxed by sip as QVariants with the user type > "PyQt_PyObject" (or something like that). > > For decimal.Decimal, the solution seems relatively easy. Retrieve the > PyObject* from the QVariant passed to my serializer, test whether it is > indeed a Decimal instance and if so, serialize it so that I can later > recognize it as a Decimal in the deserializer. There, I create a > PyObject* of type Decimal with the saved data, pack it in a QVariant and > return it. > > For tuples and sets, it seems a little more complicated. Since I can > only retrieve the elements as PyObject pointers, I can't just > recursively call my serialize(QVariant) function. I also can't just put > them in a QVariant with the "PyQt_PyObject" user type because the > PyObject may actually be a float, QPoint or something else that is > natively supported by QVariant. > > Which brings us back to my above question. I have seen the > "qpycore_PyObject_AsQVariant" and "qpycore_PyObject_FromQVariant" in > QtCore/qvariant.sip, but since they don't seem to be documented > anywhere, I am unsure whether they are a strictly internal feature. They are internal. Your use case seems reasonable so I'm happy to change things to accomodate it. It sounds like what is needed is something similar to %ConvertToTypeCode and %ConvertFromTypeCode but that can be applied to a type SIP already knows about (ie. QVariant) rather than as part of the specification of a new type. Would this give you what you want? Phil _______________________________________________ PyQt mailing list PyQt@riverbankcomputing.com http://www.riverbankcomputing.com/mailman/listinfo/pyqt
