I have a GUI application written in Python (with WxPython) which uses
some low level classes also written in Python. These low level Python
classes are given a pointer to some GUI Python object. The low level
Python classes callback some of the methods of the GUI object. All
works fine.
Now I want to convert the low level Python classes to C++. I will be
using SWIG to create the marshaling so the top level GUI, written in
Python stays that way.
The problem: is it possible to continue using call backs? The C++ code
would need to call the Python methods back. Is there an easy way to do
this?
This is a little different from extending or embedding. I have a Python
program that uses Python extensions written in C++. This C++ code would
need to pass some information back to the Python code (and currently,
the all-round Python code uses call backs).
My quick review of the SWIG documentation did not help me find a
solution to this.
Thanks in advance for any help.
/Pierre 2 4073
In article <OK************ *****@news20.be llglobal.com>, Pierre Rouleau
<pr************ ********@impath networks.com> writes I have a GUI application written in Python (with WxPython) which uses some low level classes also written in Python. These low level Python classes are given a pointer to some GUI Python object. The low level Python classes callback some of the methods of the GUI object. All works fine.
Now I want to convert the low level Python classes to C++. I will be using SWIG to create the marshaling so the top level GUI, written in Python stays that way.
The problem: is it possible to continue using call backs? The C++ code would need to call the Python methods back. Is there an easy way to do this?
certainly you can call back into python, I have some typical code that
looks like
PyObject *callback;
........
PyObject *arglist;
PyObject *result;
arglist = Py_BuildValue(" (s)",buf);
result = PyEval_CallObje ct(callback, arglist);
Py_DECREF(argli st);
if(result){
Py_DECREF(resul t);
/*success*/
}
else {
/*handle error*/
}
Of course you need to get the definition of callback somehow. But that
is easy via argument passing or obtaining a global function.
This is a little different from extending or embedding. I have a Python program that uses Python extensions written in C++. This C++ code would need to pass some information back to the Python code (and currently, the all-round Python code uses call backs).
......Thanks in advance for any help.
/Pierre
--
Robin Becker
Sure. Explanation by example:
Python code:
#v+
def myfunc(): pass
foobar.register _callback(myfun c)
#v-
C code:
#v+
PyObject* register_callba ck(FooType* self, PyObject* args, PyObject**
kwargs)
{
/* ParseTupleAndKe ywords */
/* PyCallable_Chec k */
self->callback = ...
}
....
function_result = PyObject_CallOb ject(callback, calling_args);
....
#v-
No idea about SWIG, but I do this a lot in the PySQLite code using
Python's raw C API, which you could use as an example: http://cvs.sourceforge.net/cgi-bin/v...viewcvs-markup
HTH,
-- Gerhard This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
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