gstreamer/gst/pygstminiobject.c

/* -*- Mode: C; c-basic-offset: 4 -*-
 * pygtk- Python bindings for the GTK toolkit.
 * Copyright (C) 1998-2003  James Henstridge
 *
 *   pygobject.c: wrapper for the GObject type.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#define NO_IMPORT_PYGOBJECT
#include "pygstminiobject.h"
#include <gst/gst.h>

static const gchar pygstminiobject_class_id[] = "PyGstMiniObject::class";
static GQuark pygstminiobject_class_key = 0;
/* static const gchar pygstminiobject_wrapper_id[]   = "PyGstMiniObject::wrapper"; */
/* static GQuark      pygstminiobject_wrapper_key  = 0; */

static void pygstminiobject_dealloc (PyGstMiniObject * self);
/* static int  pygstminiobject_traverse(PyGstMiniObject *self, visitproc visit, void *arg); */
/* static int  pygstminiobject_clear(PyGstMiniObject *self); */

GST_DEBUG_CATEGORY_EXTERN (pygst_debug);
#define GST_CAT_DEFAULT pygst_debug

/**
 * pygstminiobject_lookup_class:
 * @gtype: the GType of the GstMiniObject subclass.
 *
 * This function looks up the wrapper class used to represent
 * instances of a GstMiniObject represented by @gtype.  If no wrapper class
 * or interface has been registered for the given GType, then a new
 * type will be created.
 *
 * Returns: The wrapper class for the GstMiniObject or NULL if the
 *          GType has no registered type and a new type couldn't be created
 */
PyTypeObject *
pygstminiobject_lookup_class (GType gtype)
{
  PyTypeObject *py_type = NULL;
  GType ctype = gtype;

  while (!py_type && ctype) {
    py_type = g_type_get_qdata (ctype, pygstminiobject_class_key);
    ctype = g_type_parent (ctype);
  }
  if (!ctype)
    g_error ("Couldn't find a good base type!!");

  return py_type;
}

/**
 * pygstminiobject_register_class:
 * @dict: the module dictionary.  A reference to the type will be stored here.
 * @type_name: not used ?
 * @gtype: the GType of the Gstminiobject subclass.
 * @type: the Python type object for this wrapper.
 * @bases: a tuple of Python type objects that are the bases of this type.
 *
 * This function is used to register a Python type as the wrapper for
 * a particular Gstminiobject subclass.  It will also insert a reference to
 * the wrapper class into the module dictionary passed as a reference,
 * which simplifies initialisation.
 */
void
pygstminiobject_register_class (PyObject * dict, const gchar * type_name,
    GType gtype, PyTypeObject * type, PyObject * bases)
{
  PyObject *o;
  const char *class_name, *s;

  if (!pygstminiobject_class_key)
    pygstminiobject_class_key =
        g_quark_from_static_string (pygstminiobject_class_id);

  class_name = type->tp_name;
  s = strrchr (class_name, '.');
  if (s != NULL)
    class_name = s + 1;

  type->ob_type = &PyType_Type;
  type->tp_alloc = PyType_GenericAlloc;
  type->tp_new = PyType_GenericNew;
  if (bases) {
    type->tp_bases = bases;
    type->tp_base = (PyTypeObject *) PyTuple_GetItem (bases, 0);
  }

  if (PyType_Ready (type) < 0) {
    g_warning ("couldn't make the type `%s' ready", type->tp_name);
    return;
  }

  if (gtype) {
    o = pyg_type_wrapper_new (gtype);
    PyDict_SetItemString (type->tp_dict, "__gtype__", o);
    Py_DECREF (o);

    /* stash a pointer to the python class with the GType */
    Py_INCREF (type);
    g_type_set_qdata (gtype, pygstminiobject_class_key, type);
  }

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

void
pygstminiobject_register_wrapper (PyObject * self)
{
}


/**
 * pygstminiobject_new:
 * @obj: a GstMiniObject instance.
 *
 * This function gets a reference to a wrapper for the given GstMiniObject
 * instance.  A new wrapper will always be created.
 *
 * Returns: a reference to the wrapper for the GstMiniObject.
 */
PyObject *
pygstminiobject_new (GstMiniObject * obj)
{
  PyGstMiniObject *self = NULL;
  PyGILState_STATE state;
  PyTypeObject *tp = NULL;

  if (obj == NULL) {
    Py_INCREF (Py_None);
    return Py_None;
  }

  /* since mini objects cannot notify us when they get destroyed, we
   * can't use a global hash to map GMO to PyO, and have to create a new
   * Python object every time we see it */
  tp = pygstminiobject_lookup_class (G_OBJECT_TYPE (obj));
  GST_DEBUG ("have to create wrapper for object %p", obj);
  if (!tp)
    g_warning ("Couldn't get class for type object : %p", obj);
  if (tp->tp_flags & Py_TPFLAGS_HEAPTYPE) {
    GST_INFO ("Increment refcount %p", tp);
    Py_INCREF (tp);
  }
  state = pyg_gil_state_ensure ();
  self = PyObject_New (PyGstMiniObject, tp);
  pyg_gil_state_release (state);

  if (self == NULL)
    return NULL;
  self->obj = gst_mini_object_ref (obj);

  self->inst_dict = NULL;
  self->weakreflist = NULL;

  GST_DEBUG ("created Python object %p for GstMiniObject %p [ref:%d]",
      self, obj, GST_MINI_OBJECT_REFCOUNT_VALUE (obj));
  return (PyObject *) self;
}

static void
pygstminiobject_dealloc (PyGstMiniObject * self)
{
  PyGILState_STATE state;

  g_return_if_fail (self != NULL);

  GST_DEBUG ("At the beginning %p", self);
  state = pyg_gil_state_ensure ();

  if (self->obj) {
    GST_DEBUG ("PyO %p unreffing GstMiniObject %p [ref:%d]", self,
        self->obj, GST_MINI_OBJECT_REFCOUNT_VALUE (self->obj));
    gst_mini_object_unref (self->obj);
    GST_DEBUG ("setting self %p -> obj to NULL", self);
    self->obj = NULL;
  }

  if (self->inst_dict) {
    Py_DECREF (self->inst_dict);
    self->inst_dict = NULL;
  }

  self->ob_type->tp_free ((PyObject *) self);
  pyg_gil_state_release (state);
  GST_DEBUG ("At the end %p", self);
}

static int
pygstminiobject_compare (PyGstMiniObject * self, PyGstMiniObject * v)
{
  if (self->obj == v->obj)
    return 0;
  if (self->obj > v->obj)
    return -1;
  return 1;
}

static long
pygstminiobject_hash (PyGstMiniObject * self)
{
  return (long) self->obj;
}

static PyObject *
pygstminiobject_repr (PyGstMiniObject * self)
{
  gchar buf[256];

  g_snprintf (buf, sizeof (buf),
      "<%s mini-object (%s) at 0x%lx>",
      self->ob_type->tp_name,
      self->obj ? G_OBJECT_TYPE_NAME (self->obj) : "uninitialized",
      (long) self);
  return PyString_FromString (buf);
}


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


/* ---------------- PyGstMiniObject methods ----------------- */

static int
pygstminiobject_init (PyGstMiniObject * self, PyObject * args,
    PyObject * kwargs)
{
  GType object_type;
  GstMiniObjectClass *class;

  if (!PyArg_ParseTuple (args, ":GstMiniObject.__init__", &object_type))
    return -1;

  object_type = pyg_type_from_object ((PyObject *) self);
  if (!object_type)
    return -1;

  if (G_TYPE_IS_ABSTRACT (object_type)) {
    PyErr_Format (PyExc_TypeError, "cannot create instance of abstract "
        "(non-instantiable) type `%s'", g_type_name (object_type));
    return -1;
  }

  if ((class = g_type_class_ref (object_type)) == NULL) {
    PyErr_SetString (PyExc_TypeError,
        "could not get a reference to type class");
    return -1;
  }

  self->obj = gst_mini_object_new (object_type);
  if (self->obj == NULL)
    PyErr_SetString (PyExc_RuntimeError, "could not create object");

  g_type_class_unref (class);

  return (self->obj) ? 0 : -1;
}

static PyObject *
pygstminiobject__gstminiobject_init__ (PyGstMiniObject * self, PyObject * args,
    PyObject * kwargs)
{
  if (pygstminiobject_init (self, args, kwargs) < 0)
    return NULL;
  Py_INCREF (Py_None);
  return Py_None;
}

static PyObject *
pygstminiobject_copy (PyGstMiniObject * self, PyObject * args)
{
  return pygstminiobject_new (gst_mini_object_copy (self->obj));
}

static PyMethodDef pygstminiobject_methods[] = {
  {"__gstminiobject_init__",
        (PyCFunction) pygstminiobject__gstminiobject_init__,
      METH_VARARGS | METH_KEYWORDS},
  {"copy", (PyCFunction) pygstminiobject_copy, METH_VARARGS,
      "Copies the miniobject"},
  {NULL, NULL, 0}
};

static PyObject *
pygstminiobject_get_dict (PyGstMiniObject * self, void *closure)
{
  if (self->inst_dict == NULL) {
    self->inst_dict = PyDict_New ();
    if (self->inst_dict == NULL)
      return NULL;
  }
  Py_INCREF (self->inst_dict);
  return self->inst_dict;
}

static PyObject *
pygstminiobject_get_refcount (PyGstMiniObject * self, void *closure)
{
  return PyInt_FromLong (GST_MINI_OBJECT_REFCOUNT_VALUE (self->obj));
}

static PyObject *
pygstminiobject_get_flags (PyGstMiniObject * self, void *closure)
{
  return PyInt_FromLong (GST_MINI_OBJECT_FLAGS (self->obj));
}

static PyGetSetDef pygstminiobject_getsets[] = {
  {"__dict__", (getter) pygstminiobject_get_dict, (setter) 0},
  {"__grefcount__", (getter) pygstminiobject_get_refcount, (setter) 0,},
  {"flags", (getter) pygstminiobject_get_flags, (setter) 0,},
  {NULL, 0, 0}
};

PyTypeObject PyGstMiniObject_Type = {
  PyObject_HEAD_INIT (NULL)
      0,                        /* ob_size */
  "gst.MiniObject",             /* tp_name */
  sizeof (PyGstMiniObject),     /* tp_basicsize */
  0,                            /* tp_itemsize */
  /* methods */
  (destructor) pygstminiobject_dealloc, /* tp_dealloc */
  (printfunc) 0,                /* tp_print */
  (getattrfunc) 0,              /* tp_getattr */
  (setattrfunc) 0,              /* tp_setattr */
  (cmpfunc) pygstminiobject_compare,    /* tp_compare */
  (reprfunc) pygstminiobject_repr,      /* tp_repr */
  0,                            /* tp_as_number */
  0,                            /* tp_as_sequence */
  0,                            /* tp_as_mapping */
  (hashfunc) pygstminiobject_hash,      /* tp_hash */
  (ternaryfunc) 0,              /* tp_call */
  (reprfunc) 0,                 /* tp_str */
  (getattrofunc) 0,             /* tp_getattro */
  (setattrofunc) 0,             /* tp_setattro */
  0,                            /* tp_as_buffer */
  Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,     /* tp_flags */
  NULL,                         /* Documentation string */
  (traverseproc) 0,             /* tp_traverse */
  (inquiry) 0,                  /* tp_clear */
  (richcmpfunc) 0,              /* tp_richcompare */
  offsetof (PyGstMiniObject, weakreflist),      /* tp_weaklistoffset */
  (getiterfunc) 0,              /* tp_iter */
  (iternextfunc) 0,             /* tp_iternext */
  pygstminiobject_methods,      /* tp_methods */
  0,                            /* tp_members */
  pygstminiobject_getsets,      /* tp_getset */
  (PyTypeObject *) 0,           /* tp_base */
  (PyObject *) 0,               /* tp_dict */
  0,                            /* tp_descr_get */
  0,                            /* tp_descr_set */
  offsetof (PyGstMiniObject, inst_dict),        /* tp_dictoffset */
  (initproc) pygstminiobject_init,      /* tp_init */
  (allocfunc) 0,                /* tp_alloc */
  (newfunc) 0,                  /* tp_new */
  (freefunc) pygstminiobject_free,      /* tp_free */
  (inquiry) 0,                  /* tp_is_gc */
  (PyObject *) 0,               /* tp_bases */
};