path: root/gi/pygpointer.c

/* -*- Mode: C; c-basic-offset: 4 -*-
 * pygtk- Python bindings for the GTK toolkit.
 * Copyright (C) 1998-2003  James Henstridge
 *
 *   pygpointer.c: wrapper for GPointer
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>

#include <Python.h>
#include <glib-object.h>
#include "pygpointer.h"
#include "pygi-type.h"
#include "pygi-type.h"
#include "pygi-util.h"


GQuark pygpointer_class_key;

PYGI_DEFINE_TYPE("gobject.GPointer", PyGPointer_Type, PyGPointer);

static void
pyg_pointer_dealloc(PyGPointer *self)
{
    Py_TYPE(self)->tp_free((PyObject *)self);
}

static PyObject*
pyg_pointer_richcompare(PyObject *self, PyObject *other, int op)
{
    if (Py_TYPE(self) == Py_TYPE(other))
        return pyg_ptr_richcompare (pyg_pointer_get_ptr (self),
                                    pyg_pointer_get_ptr (other),
                                    op);
    else {
        Py_INCREF(Py_NotImplemented);
        return Py_NotImplemented;
    }
}

static Py_hash_t
pyg_pointer_hash(PyGPointer *self)
{
    return (Py_hash_t)(gintptr)(pyg_pointer_get_ptr (self));
}

static PyObject *
pyg_pointer_repr(PyGPointer *self)
{
    gchar buf[128];

    g_snprintf(buf, sizeof(buf), "<%s at 0x%" G_GUINTPTR_FORMAT ">",
               g_type_name(self->gtype),
               (guintptr)pyg_pointer_get_ptr (self));
    return PyUnicode_FromString (buf);
}

static int
pyg_pointer_init(PyGPointer *self, PyObject *args, PyObject *kwargs)
{
    gchar buf[512];

    if (!PyArg_ParseTuple(args, ":GPointer.__init__"))
	return -1;

    pyg_pointer_set_ptr (self, NULL);
    self->gtype = 0;

    g_snprintf(buf, sizeof(buf), "%s can not be constructed",
	       Py_TYPE(self)->tp_name);
    PyErr_SetString(PyExc_NotImplementedError, buf);
    return -1;
}

static void
pyg_pointer_free(PyObject *op)
{
  PyObject_FREE(op);
}

/**
 * pyg_register_pointer:
 * @dict: the module dictionary to store the wrapper class.
 * @class_name: the Python name for the wrapper class.
 * @pointer_type: the GType of the pointer type being wrapped.
 * @type: the wrapper class.
 *
 * Registers a wrapper for a pointer type.  The wrapper class will be
 * a subclass of gobject.GPointer, and a reference to the wrapper
 * class will be stored in the provided module dictionary.
 */
void
pyg_register_pointer(PyObject *dict, const gchar *class_name,
		     GType pointer_type, PyTypeObject *type)
{
    PyObject *o;

    g_return_if_fail(dict != NULL);
    g_return_if_fail(class_name != NULL);
    g_return_if_fail(pointer_type != 0);

    if (!type->tp_dealloc) type->tp_dealloc = (destructor)pyg_pointer_dealloc;

    Py_SET_TYPE(type, &PyType_Type);
    g_assert (Py_TYPE (&PyGPointer_Type) != NULL);
    type->tp_base = &PyGPointer_Type;

    if (PyType_Ready(type) < 0) {
	g_warning("could not get type `%s' ready", type->tp_name);
	return;
    }

    PyDict_SetItemString(type->tp_dict, "__gtype__",
			 o=pyg_type_wrapper_new(pointer_type));
    Py_DECREF(o);

    g_type_set_qdata(pointer_type, pygpointer_class_key, type);

    PyDict_SetItemString(dict, (char *)class_name, (PyObject *)type);
}

/**
 * pyg_pointer_new:
 * @pointer_type: the GType of the pointer value.
 * @pointer: the pointer value.
 *
 * Creates a wrapper for a pointer value.  Since G_TYPE_POINTER types
 * don't register any information about how to copy/free them, there
 * is no guarantee that the pointer will remain valid, and there is
 * nothing registered to release the pointer when the pointer goes out
 * of scope.  This is why we don't recommend people use these types.
 *
 * Returns: the boxed wrapper.
 */
PyObject *
pyg_pointer_new(GType pointer_type, gpointer pointer)
{
    PyGILState_STATE state;
    PyGPointer *self;
    PyTypeObject *tp;
    g_return_val_if_fail(pointer_type != 0, NULL);

    state = PyGILState_Ensure();

    if (!pointer) {
	Py_INCREF(Py_None);
	PyGILState_Release(state);
	return Py_None;
    }

    tp = g_type_get_qdata(pointer_type, pygpointer_class_key);

    if (!tp)
        tp = (PyTypeObject *)pygi_type_import_by_g_type(pointer_type);

    if (!tp)
	tp = (PyTypeObject *)&PyGPointer_Type; /* fallback */
    self = PyObject_NEW(PyGPointer, tp);

    PyGILState_Release(state);

    if (self == NULL)
	return NULL;

    pyg_pointer_set_ptr (self, pointer);
    self->gtype = pointer_type;

    return (PyObject *)self;
}

/**
 * Returns 0 on success, or -1 and sets an exception.
 */
int
pygi_pointer_register_types(PyObject *d)
{
    PyObject *pygtype;

    pygpointer_class_key     = g_quark_from_static_string("PyGPointer::class");

    PyGPointer_Type.tp_dealloc = (destructor)pyg_pointer_dealloc;
    PyGPointer_Type.tp_richcompare = pyg_pointer_richcompare;
    PyGPointer_Type.tp_repr = (reprfunc)pyg_pointer_repr;
    PyGPointer_Type.tp_hash = (hashfunc)pyg_pointer_hash;
    PyGPointer_Type.tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE;
    PyGPointer_Type.tp_init = (initproc)pyg_pointer_init;
    PyGPointer_Type.tp_free = (freefunc)pyg_pointer_free;
    PyGPointer_Type.tp_alloc = PyType_GenericAlloc;
    PyGPointer_Type.tp_new = PyType_GenericNew;
    if (PyType_Ready(&PyGPointer_Type))
        return -1;

    pygtype = pyg_type_wrapper_new (G_TYPE_POINTER);
    PyDict_SetItemString (PyGPointer_Type.tp_dict, "__gtype__", pygtype);
    Py_DECREF (pygtype);

    PyDict_SetItemString(d, "GPointer", (PyObject *)&PyGPointer_Type);

    return 0;
}