Hello Everybody,

I would like to use a C++ gui library with the following (simplified) interface in Python.

#include <stdio.h>

class Gui;

class GuiObject { public: GuiObject(Gui *Gui) {printf("creating GuiObject(gui: %X)\n", Gui);} ~GuiObject() {printf("deleting GuiObject\n");} void Move(int x, int y) {printf("GuiObject move(%d, %d)\n", x, y);}; };

class Gui { public: Gui() {printf("creating Gui\n");} ~Gui() {printf("deleting Gui\n");} GuiObject* AddImage() { GuiObject* ob = new GuiObject(this); return ob; } void Print() {printf("Gui: %X\n", this);} };

int main() { Gui *gui = new Gui(); gui->Print(); GuiObject *obj = gui->AddImage(); obj->Move(50, 50); /*GuiObject *obj2 = new GuiObject(gui); // not allowed delete obj2;*/ delete obj; delete gui; return 0; }

I created the Python Gui and GuiObject classes (PyTypeObject), and added it to main module (PyModule_AddObject). It works, but there is a problem at the Gui::AddImage(), with constructs a new GuiObject, which is available in Python layer but finally it is not collected and freed by GC:

... obj = _PyObject_New(&GuiObjectType); PyObject_Init(obj, &GuiObjectType); ...

I cannot invoke the GuiObject object constructor directly from Python, because of the implementation of the C++ gui library (in this case it would be collected). I use the embedded CPython as an interpreter, so I cannot add additional external .py file for it.

So the following Python code would be the target:

gui = GUI();

background = gui.AddImage(); #background = GuiObject(gui); <-- Collected but not allowed background.ImageFile("bg.jpg"); background.Move(0, 0); ...

How could I implement the AddImage function in order to be freed the constructed object at the end?

Thanks in advance!

All-the-best,

Csaba