Function add_hook_list

Pythonwin/win32cmd.cpp:198–231

//////////////////////////////////////////////////////////////// add_hook_list keep a reference to the hooked object. Return old handler, or None

// keep a reference to the hooked object.
// Return old handler, or None
PyObject *add_hook_list(PyObject *hookedObject, PyObject *args, CMapWordToPtr **ppList)
{
	CMapWordToPtr *&pList = *ppList;
	if (pList==NULL)
		pList = new CMapWordToPtr();
	PyObject *method;
	int message;
	if (!PyArg_ParseTuple(args,"Oi",&method, &message))
		return NULL;
	if (method!=Py_None && !PyCallable_Check(method))
		RETURN_ERR("The parameter must be a callable object or None");

	void *oldMethod = NULL;
	// note I maybe decref, then maybe incref.  To ensure the object will
	// not be destroyed (ie, ref go to zero) between the 2 calls), I
	// add a temporary reference first.
	DOINCREF(hookedObject);
	if (pList->Lookup(message, oldMethod)) {
		pList->RemoveKey(message);
		// oldMethod is returned - don't drop its reference.
		DODECREF(hookedObject);
	}
	if (method!=Py_None) {
		Py_INCREF(method);
		pList->SetAt(message,method);
		Py_INCREF(hookedObject);
	}
	DODECREF(hookedObject); // remove temp reference added above.
	if (oldMethod)
		return (PyObject *)oldMethod;
	else
		RETURN_NONE;
//	RETURN_NONE;
}
//
// free_hook_list
//