[PyKDE] Filling QPixmap from C code

[Phil Thompson]

On Wednesday 16 April 2003 8:23 am, Giaco777 wrote:
> Hi PyQters,
>
> first of all I would like to thank Phil for this great RAD environment
> for QT.
>
> In my application I would like a QPixmap generated by PYQt
> to be filled by a C subroutine. My first try would look like this (in
> principal):
>
> Python:
>
> qp=QPixmap(...)
> fillQPixmap(qp)     # this is realized in C
>
> C:
>
> // this is the C subroutine which fills QPixmap
> static PyObject *fillQPixmap(PyObject *self, PyObject *args) {
>     PyObject * po;
>     if(!PyArg_ParseTuple(args, "O", &po)) return NULL;
>
>     // interpret object as QPixmap pointer
>    QPixmap *pm = (QPixmap*) PyCObject_AsVoidPtr(po);
>
>    // do something with pm
>
>    Py_INCREF(Py_None);
>    return Py_None;
> }
>
>
> Is there a chance that this will work or is there a better solution?

There is no chance that this will work because po is a class instance and the 
real C++ pointer is buried deep within in.

You need something like...

	// interpret object as QPixmap pointer
	int iserr = FALSE;

	QPixmap *pm = (QPixmap *)sipConvertToCpp(po,sipClass_QPixmap,&iserr);

	if (iserr)
		return NULL;

	if (pm == NULL)
	{
		raise_exception_about_None_being_passed();
		return NULL;
	}

Phil