Hi, recently I needed to use weakrefs and found them a bit awkward
because they need to accept a python function when that function is
(usually/always?) a C function.
Heres an example of a weakref callback in C...
Anyone know if theres a nicer way to use PyCFunction_New, rather then
define a PyMethodDef beforehand?
Id prefer if you could just pass the C function as the weakref callback,
perhaps it would be possible to have an alternate PyWeakref_NewProxy
function that accepted a C function as a callback.
heres the weakref callback method I used....
_________
/* c function*/
PyObject * arm_weakref_callback_weakref_dealloc(PyObject *self, PyObject
*weakref);
/* python callable */
PyObject * arm_weakref_callback_weakref_dealloc__pyfunc;
/* internal func to remove weakref from weakref list */
PyObject * arm_weakref_callback_weakref_dealloc(PyObject *self, PyObject
*weakref)
{
char *list_name = ARM_WEAKREF_LIST_NAME;
PyObject *maindict = NULL, *armlist = NULL;
int i;
/* error checking below removed */
maindict= PyModule_GetDict(PyImport_AddModule( "__main__"));
armlist = PyDict_GetItemString(maindict, list_name);
i = PySequence_Index(armlist, weakref);
PySequence_DelItem(armlist, i);
Py_RETURN_NONE;
}
PyObject *Armature_CreatePyObject(struct bArmature *armature)
{
/* snip----- */
weakref = PyWeakref_NewProxy((PyObject*)py_armature,
arm_weakref_callback_weakref_dealloc__pyfunc);
/* snip----- */
return (PyObject *) py_armature;
}
/* internal use only */
static PyMethodDef bpy_arm_weakref_callback_weakref_dealloc[] = {
{"arm_weakref_callback_weakref_dealloc",
arm_weakref_callback_weakref_dealloc, METH_O, ""}
};
//-------------------MODULE INITIALIZATION--------------------------------
PyObject *Armature_Init(void)
{
/* snip----- */
arm_weakref_callback_weakref_dealloc__pyfunc =
PyCFunction_New(bpy_arm_weakref_callback_weakref_dealloc, NULL);
/* snip----- */
}
--
Campbell J Barton (ideasman42)
