path: root/gi/pyglib.c

/* -*- Mode: C; c-set-style: python; c-basic-offset: 4  -*-
 * pyglib - Python bindings for GLib toolkit.
 * Copyright (C) 1998-2003  James Henstridge
 *               2004-2008  Johan Dahlin
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 * USA
 */

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <Python.h>
#include <pythread.h>
#include "pyglib.h"
#include "pyglib-private.h"
#include "pygoptioncontext.h"
#include "pygoptiongroup.h"

static PyObject *exception_table = NULL;

/**
 * pyglib_error_marshal:
 * @error: a pointer to the GError.
 *
 * Checks to see if @error has been set.  If @error has been set, then a
 * GLib.GError Python exception object is returned (but not raised).
 *
 * Returns: a GLib.GError Python exception object, or NULL.
 */
PyObject *
pyglib_error_marshal (GError **error)
{
    PyGILState_STATE state;
    PyObject *exc_type;
    PyObject *exc_instance;
    PyObject *d;

    g_return_val_if_fail(error != NULL, NULL);

    if (*error == NULL)
	return NULL;

    state = pyglib_gil_state_ensure();

    exc_type = PyGError;
    if (exception_table != NULL)
    {
	PyObject *item;
	item = PyDict_GetItem(exception_table, PYGLIB_PyLong_FromLong((*error)->domain));
	if (item != NULL)
	    exc_type = item;
    }

    exc_instance = PyObject_CallFunction(exc_type, "z", (*error)->message);

    if ((*error)->domain) {
	PyObject_SetAttrString(exc_instance, "domain",
			       d=PYGLIB_PyUnicode_FromString(g_quark_to_string((*error)->domain)));
	Py_DECREF(d);
    }
    else
	PyObject_SetAttrString(exc_instance, "domain", Py_None);

    PyObject_SetAttrString(exc_instance, "code",
			   d=PYGLIB_PyLong_FromLong((*error)->code));
    Py_DECREF(d);

    if ((*error)->message) {
	PyObject_SetAttrString(exc_instance, "message",
			       d=PYGLIB_PyUnicode_FromString((*error)->message));
	Py_DECREF(d);
    } else {
	PyObject_SetAttrString(exc_instance, "message", Py_None);
    }

    pyglib_gil_state_release(state);
    
    return exc_instance;
}

/**
 * pyglib_error_check:
 * @error: a pointer to the GError.
 *
 * Checks to see if the GError has been set.  If the error has been
 * set, then the glib.GError Python exception will be raised, and
 * the GError cleared.
 *
 * Returns: True if an error was set.
 */
gboolean
pyglib_error_check(GError **error)
{
    PyGILState_STATE state;
    PyObject *exc_instance;

    g_return_val_if_fail(error != NULL, FALSE);
    if (*error == NULL)
	return FALSE;

    state = pyglib_gil_state_ensure();

    exc_instance = pyglib_error_marshal (error);
    PyErr_SetObject(PyGError, exc_instance);
    Py_DECREF(exc_instance);
    g_clear_error(error);
    
    pyglib_gil_state_release(state);
    
    return TRUE;
}

/**
 * pyglib_gerror_exception_check:
 * @error: a standard GLib GError ** output parameter
 *
 * Checks to see if a GError exception has been raised, and if so
 * translates the python exception to a standard GLib GError.  If the
 * raised exception is not a GError then PyErr_Print() is called.
 *
 * Returns: 0 if no exception has been raised, -1 if it is a
 * valid glib.GError, -2 otherwise.
 */
gboolean
pyglib_gerror_exception_check(GError **error)
{
    PyObject *type, *value, *traceback;
    PyObject *py_message, *py_domain, *py_code;
    const char *bad_gerror_message;

    PyErr_Fetch(&type, &value, &traceback);
    if (type == NULL)
        return 0;
    PyErr_NormalizeException(&type, &value, &traceback);
    if (value == NULL) {
        PyErr_Restore(type, value, traceback);
        PyErr_Print();
        return -2;
    }
    if (!value ||
	!PyErr_GivenExceptionMatches(type,
				     (PyObject *) PyGError)) {
        PyErr_Restore(type, value, traceback);
        PyErr_Print();
        return -2;
    }
    Py_DECREF(type);
    Py_XDECREF(traceback);

    py_message = PyObject_GetAttrString(value, "message");
    if (!py_message || !PYGLIB_PyUnicode_Check(py_message)) {
        bad_gerror_message = "gi._glib.GError instances must have a 'message' string attribute";
        Py_XDECREF(py_message);
        goto bad_gerror;
    }

    py_domain = PyObject_GetAttrString(value, "domain");
    if (!py_domain || !PYGLIB_PyUnicode_Check(py_domain)) {
        bad_gerror_message = "gi._glib.GError instances must have a 'domain' string attribute";
        Py_DECREF(py_message);
        Py_XDECREF(py_domain);
        goto bad_gerror;
    }

    py_code = PyObject_GetAttrString(value, "code");
    if (!py_code || !PYGLIB_PyLong_Check(py_code)) {
        bad_gerror_message = "gi._glib.GError instances must have a 'code' int attribute";
        Py_DECREF(py_message);
        Py_DECREF(py_domain);
        Py_XDECREF(py_code);
        goto bad_gerror;
    }

    g_set_error(error, g_quark_from_string(PYGLIB_PyUnicode_AsString(py_domain)),
                PYGLIB_PyLong_AsLong(py_code), "%s", PYGLIB_PyUnicode_AsString(py_message));

    Py_DECREF(py_message);
    Py_DECREF(py_code);
    Py_DECREF(py_domain);
    return -1;

bad_gerror:
    Py_DECREF(value);
    g_set_error(error, g_quark_from_static_string("pyglib"), 0, "%s", bad_gerror_message);
    PyErr_SetString(PyExc_ValueError, bad_gerror_message);
    PyErr_Print();
    return -2;
}

/**
 * pyglib_register_exception_for_domain:
 * @name: name of the exception
 * @error_domain: error domain
 *
 * Registers a new glib.GError exception subclass called #name for
 * a specific #domain. This exception will be raised when a GError
 * of the same domain is passed in to pyglib_error_check().
 *
 * Returns: the new exception
 */
PyObject *
pyglib_register_exception_for_domain(gchar *name,
				     gint error_domain)
{
    PyObject *exception;

    exception = PyErr_NewException(name, PyGError, NULL);

    if (exception_table == NULL)
	exception_table = PyDict_New();

    PyDict_SetItem(exception_table,
		   PYGLIB_PyLong_FromLong(error_domain),
		   exception);
    
    return exception;
}

/**
 * pyg_option_group_transfer_group:
 * @group: a GOptionGroup wrapper
 *
 * This is used to transfer the GOptionGroup to a GOptionContext. After this
 * is called, the calle must handle the release of the GOptionGroup.
 *
 * When #NULL is returned, the GOptionGroup was already transfered.
 *
 * Returns: Either #NULL or the wrapped GOptionGroup.
 */
GOptionGroup *
pyglib_option_group_transfer_group(PyObject *obj)
{
    PyGOptionGroup *self = (PyGOptionGroup*)obj;
    
    if (self->is_in_context)
	return NULL;

    self->is_in_context = TRUE;
    
    /* Here we increase the reference count of the PyGOptionGroup, because now
     * the GOptionContext holds an reference to us (it is the userdata passed
     * to g_option_group_new().
     *
     * The GOptionGroup is freed with the GOptionContext.
     *
     * We set it here because if we would do this in the init method we would
     * hold two references and the PyGOptionGroup would never be freed.
     */
    Py_INCREF(self);
    
    return self->group;
}


/****** Private *****/

/**
 * _pyglib_destroy_notify:
 * @user_data: a PyObject pointer.
 *
 * A function that can be used as a GDestroyNotify callback that will
 * call Py_DECREF on the data.
 */
void
_pyglib_destroy_notify(gpointer user_data)
{
    PyObject *obj = (PyObject *)user_data;
    PyGILState_STATE state;

    state = pyglib_gil_state_ensure();
    Py_DECREF(obj);
    pyglib_gil_state_release(state);
}

gboolean
_pyglib_handler_marshal(gpointer user_data)
{
    PyObject *tuple, *ret;
    gboolean res;
    PyGILState_STATE state;

    g_return_val_if_fail(user_data != NULL, FALSE);

    state = pyglib_gil_state_ensure();

    tuple = (PyObject *)user_data;
    ret = PyObject_CallObject(PyTuple_GetItem(tuple, 0),
			      PyTuple_GetItem(tuple, 1));
    if (!ret) {
	PyErr_Print();
	res = FALSE;
    } else {
	res = PyObject_IsTrue(ret);
	Py_DECREF(ret);
    }
    
    pyglib_gil_state_release(state);

    return res;
}

PyObject*
_pyglib_generic_ptr_richcompare(void* a, void *b, int op)
{
    PyObject *res;

    switch (op) {

      case Py_EQ:
        res = (a == b) ? Py_True : Py_False;
        break;

      case Py_NE:
        res = (a != b) ? Py_True : Py_False;
        break;

      case Py_LT:
        res = (a < b) ? Py_True : Py_False;
        break;

      case Py_LE:
        res = (a <= b) ? Py_True : Py_False;
        break;

      case Py_GT:
        res = (a > b) ? Py_True : Py_False;
        break;

      case Py_GE:
        res = (a >= b) ? Py_True : Py_False;
        break;

      default:
        res = Py_NotImplemented;
        break;
    }

    Py_INCREF(res);
    return res;
}

PyObject*
_pyglib_generic_long_richcompare(long a, long b, int op)
{
    PyObject *res;

    switch (op) {

      case Py_EQ:
        res = (a == b) ? Py_True : Py_False;
        Py_INCREF(res);
        break;

      case Py_NE:
        res = (a != b) ? Py_True : Py_False;
        Py_INCREF(res);
        break;


      case Py_LT:
        res = (a < b) ? Py_True : Py_False;
        Py_INCREF(res);
        break;

      case Py_LE:
        res = (a <= b) ? Py_True : Py_False;
        Py_INCREF(res);
        break;

      case Py_GT:
        res = (a > b) ? Py_True : Py_False;
        Py_INCREF(res);
        break;

      case Py_GE:
        res = (a >= b) ? Py_True : Py_False;
        Py_INCREF(res);
        break;

      default:
        res = Py_NotImplemented;
        Py_INCREF(res);
        break;
    }

    return res;
}