gstreamer/gst/gstcaps.override

/* -*- Mode: C; c-basic-offset: 4 -*- */
/* gst-python
 * Copyright (C) 2005 Johan Dahlin
 *		 2005 Benjamin Otte <otte@gnome.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library 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.
 * 
 * Author: Johan Dahlin <johan@gnome.org>
 *	   Benjamin Otte <otte@gnome.org>
 */
%%
headers
/* This is a (hopefully) smart hack to allow access to a caps' 
 * structures without falling into traps when the caps get destroyed
 * before the structures get.
 * This Hash Table uses the structure PyObjects as keys and the caps 
 * PyObjects as values. No clue if this is a fast data structure but it
 * probably doesn't matter anyway.
 */
static GHashTable *structure_caps_map = NULL;

static void
pygst_caps_map_add (PyObject *structure, PyObject *caps)
{
  /* we can't have free_on_dealloc stuff in here */
  g_assert (((PyGBoxed *)structure)->free_on_dealloc == FALSE);
  g_hash_table_insert (structure_caps_map, structure, caps);
}

static void
pygst_caps_map_remove_structure (PyObject *structure)
{
  g_hash_table_remove (structure_caps_map, structure);
}

static gboolean
pygst_caps_map_foreach (gpointer structure, gpointer caps, gpointer match)
{
  PyGBoxed *boxed = structure;
  
  if (match != caps)
    return FALSE;

  /* we can't have free_on_dealloc stuff in here */
  g_assert (boxed->free_on_dealloc == FALSE);
  boxed->boxed = gst_structure_copy (boxed->boxed);
  boxed->free_on_dealloc = TRUE;
  return TRUE;
}

static void
pygst_caps_map_modified (PyObject *caps)
{
  g_hash_table_foreach_remove (structure_caps_map, pygst_caps_map_foreach, caps);
}

%%
init
  structure_caps_map = g_hash_table_new (g_direct_hash, g_direct_equal);
%%
ignore
  gst_caps_new_simple
  gst_caps_new_full
  gst_caps_set_simple
%%
override gst_caps_get_structure kwargs
static PyObject *pygst_caps_sq_item(PyObject *self, int i);
static PyObject *
_wrap_gst_caps_get_structure(PyObject *self, PyObject *args, PyObject *kwargs)
{
	static char *kwlist[] = { "index", NULL };
	int index;

	if (PyErr_Warn(PyExc_DeprecationWarning, "caps.get_structure(i) is deprecated, use caps[i]") < 0)
		return NULL;
	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "i:GstCaps.get_structure", kwlist, &index))
		return NULL;
	return pygst_caps_sq_item (self, index);
}
%%
override gst_caps_new_empty kwargs
static int
_wrap_gst_caps_new_empty(PyGBoxed *self, PyObject *args, PyObject *kwargs)
{
	PyObject* item;
	int len, i;

        /* we wrap caps_new, caps_from_string and caps_new_full */
        len = PyTuple_Size(args);
        self->gtype = GST_TYPE_CAPS;
	self->free_on_dealloc = FALSE;
	
        if (len == 0) {
		/* 0 length creates a new empty caps */
		self->boxed = gst_caps_new_empty();
	} else if (len == 1) {
		item = PyTuple_GetItem(args, 0);
		/* 1 length is either a string or a structure */
		self->boxed = pygst_caps_from_pyobject (item, NULL);
	} else {
		/* it's multiple arguments that can all be made to caps */
		GstCaps *append;
		self->boxed = gst_caps_new_empty();
		for (i = 0; i < len; i++)
		{
			item = PyTuple_GetItem(args, i);
			append = pygst_caps_from_pyobject (item, NULL);
			if (!append) {
			      gst_caps_free (self->boxed);
			      self->boxed = NULL;
			      break;
			}
			gst_caps_append (self->boxed, append);
		}
	}
	if (!self->boxed) {
		PyErr_SetString(PyExc_TypeError, "wrong arguemntes when creating GstCaps object");
		return -1;
	}
	return 0;
}

%%
override-slot GstCaps.tp_richcompare

static gboolean
pygst_caps_is_true_subset (GstCaps *caps1, GstCaps *caps2)
{
  GstCaps *tmp;
  gboolean ret;
  
  /* order is important here */
  if (gst_caps_is_any (caps1))
    return FALSE;
  if (gst_caps_is_any (caps2))
    return TRUE;
  if (gst_caps_is_empty (caps2))
    return FALSE;
  if (gst_caps_is_empty (caps1))
    return TRUE;

  tmp = gst_caps_subtract (caps1, caps2);
  ret = gst_caps_is_empty (tmp);
  gst_caps_free (tmp);
  if (!ret)
    return FALSE;
  tmp = gst_caps_subtract (caps2, caps1);
  ret = gst_caps_is_empty (tmp);
  gst_caps_free (tmp);
  return !ret;
}

static PyObject *
_wrap_gst_caps_tp_richcompare (PyObject *py_caps1, PyObject *py_caps2, int comparison)
{
  GstCaps *caps1, *caps2; 
  gboolean caps2_is_copy;
  PyObject *ret;

  caps1 = pyg_boxed_get (py_caps1, GstCaps);
  caps2 = pygst_caps_from_pyobject (py_caps2, &caps2_is_copy);
  if (PyErr_Occurred()) {
    /* the second arg is not a caps */
    switch (comparison) {
      case Py_EQ:
        PyErr_Clear();
        ret = Py_False;
        Py_INCREF (ret);
        return ret;
      case Py_NE:
        PyErr_Clear();
        ret = Py_True;
        Py_INCREF (ret);
        return ret;
      default:
        return NULL;
    }
  }

  switch (comparison) {
    case Py_LT:
      ret = pygst_caps_is_true_subset (caps1, caps2) ? Py_True : Py_False;
      break;
    case Py_LE:
      ret = gst_caps_is_subset (caps1, caps2) ? Py_True : Py_False;
      break;
    case Py_NE:
      ret = gst_caps_is_equal (caps1, caps2) ? Py_False : Py_True;
      break;
    case Py_EQ:
      ret = gst_caps_is_equal (caps1, caps2) ? Py_True : Py_False;
      break;
    case Py_GE:
      ret = gst_caps_is_subset (caps2, caps1) ? Py_True : Py_False;
      break;
    case Py_GT:
      ret = pygst_caps_is_true_subset (caps2, caps1) ? Py_True : Py_False;
      break;
    default:
      PyErr_SetString (PyExc_RuntimeError, "invalid comparison operation");
      if (caps2 && caps2_is_copy)
	gst_caps_free (caps2);
      return NULL;
  }
  if (caps2 && caps2_is_copy)
    gst_caps_free (caps2);
  
  Py_INCREF (ret);
  return ret;
}

%%
override-slot GstCaps.tp_as_number

/* In this number code, we mimic the Python set.Set datatype.
 * The same operations are supported. If you want to have an operation
 * supported for caps, add it to Python's Set type first.
 */
#define BINARY_FUNC(name,func) \
static PyObject * \
name (PyObject *py_caps1, PyObject *py_caps2) \
{ \
  GstCaps *caps1, *caps2, *ret; \
  gboolean caps2_is_copy; \
\
  caps1 = pyg_boxed_get (py_caps1, GstCaps); \
  caps2 = pygst_caps_from_pyobject (py_caps2, &caps2_is_copy); \
  if (PyErr_Occurred()) \
    return NULL; \
  ret = func (caps1, caps2); \
  if (caps2 && caps2_is_copy) \
    gst_caps_free (caps2); \
  return pyg_boxed_new (GST_TYPE_CAPS, ret, FALSE, TRUE); \
}

BINARY_FUNC (pygst_caps_nb_subtract, gst_caps_subtract)
BINARY_FUNC (pygst_caps_nb_and, gst_caps_intersect)
BINARY_FUNC (pygst_caps_nb_or, gst_caps_union)
static GstCaps *
pygst_caps_xor (const GstCaps *caps1, const GstCaps *caps2)
{
  GstCaps *intersect, *_union, *ret;
  intersect = gst_caps_intersect (caps1, caps2);
  _union = gst_caps_union (caps1, caps2);
  ret = gst_caps_subtract (_union, intersect);
  gst_caps_free (_union);
  gst_caps_free (intersect);
  gst_caps_do_simplify (ret);
  return ret;
}
BINARY_FUNC (pygst_caps_nb_xor, pygst_caps_xor)

static int
pygst_caps_nb_nonzero (PyObject *py_caps)
{
  GstCaps *caps = pyg_boxed_get (py_caps, GstCaps);

  if (gst_caps_is_empty (caps))
    return 0;
  else
    return 1;
}

static int
pygst_caps_nb_coerce (PyObject **py_caps1, PyObject **py_caps2)
{
  GstCaps *caps1, *caps2 = NULL;
  gboolean caps1_is_copy, caps2_is_copy;
  
  caps1 = pygst_caps_from_pyobject (*py_caps1, &caps1_is_copy);
  if (!caps1)
    goto error;
  caps2 = pygst_caps_from_pyobject (*py_caps2, &caps2_is_copy);
  if (!caps2)
    goto error;
  /* if they're not copies, they're caps already */
  if (caps1_is_copy)
    *py_caps1 = pyg_boxed_new (GST_TYPE_CAPS, caps1, FALSE, TRUE);
  else
    Py_INCREF (*py_caps1);
  if (caps2_is_copy)
    *py_caps2 = pyg_boxed_new (GST_TYPE_CAPS, caps2, FALSE, TRUE);
  else
    Py_INCREF (*py_caps2);
  return 0;

error:
  g_assert (PyErr_Occurred ());
  PyErr_Clear ();
  if (caps1 && !caps1_is_copy)
    gst_caps_free (caps1);
  if (caps2 && !caps2_is_copy)
    gst_caps_free (caps2);
  return 1;
}

static PyNumberMethods _wrap_gst_caps_tp_as_number = {
	0,			      		/* nb_add */
	pygst_caps_nb_subtract,			/* nb_subtract */
	0,					/* nb_multiply */
	0,	  				/* nb_divide */
	0,					/* nb_remainder */
	0,					/* nb_divmod */
	0,			  		/* nb_power */
	0,					/* nb_negative */
	0,					/* nb_positive */
	0,					/* nb_absolute */
	pygst_caps_nb_nonzero,	      		/* nb_nonzero */
	0,					/* nb_invert */
	0,					/* nb_lshift */
	0,					/* nb_rshift */
	pygst_caps_nb_and,			/* nb_and */
	pygst_caps_nb_xor,			/* nb_xor */
	pygst_caps_nb_or,			/* nb_or */
	pygst_caps_nb_coerce,	      		/* nb_coerce */
	0,					/* nb_int */
	0,					/* nb_long */
	0,					/* nb_float */
	0,					/* nb_oct */
	0,		 			/* nb_hex */
	0,					/* nb_inplace_add */
	0,					/* nb_inplace_subtract */
	0,					/* nb_inplace_multiply */
	0,					/* nb_inplace_divide */
	0,					/* nb_inplace_remainder */
	0,					/* nb_inplace_power */
	0,					/* nb_inplace_lshift */
	0,					/* nb_inplace_rshift */
	0,					/* nb_inplace_and */
	0,					/* nb_inplace_xor */
	0,					/* nb_inplace_or */
	0,					/* nb_floor_divide */
	0,					/* nb_true_divide */
	0,					/* nb_inplace_floor_divide */
	0,					/* nb_inplace_true_divide */
};
%%
override-slot GstCaps.tp_as_sequence
static int
pygst_caps_sq_length(PyObject *self)
{
	GstCaps *caps = pyg_boxed_get (self, GstCaps);
	return gst_caps_get_size(caps);
}

static PyObject *
pygst_caps_sq_item(PyObject *self, int i)
{
	GstCaps *caps = pyg_boxed_get (self, GstCaps);
	GstStructure *structure;
	PyObject *ret;
	
	if (i < 0 || i >= gst_caps_get_size(caps)) {
		PyErr_SetString(PyExc_IndexError, "list index out of range");
		return NULL;
	}
	
	structure = gst_caps_get_structure(caps, i);
				    
	/* pyg_boxed_new handles NULL checking */
	ret = pyg_boxed_new(GST_TYPE_STRUCTURE, 
	                    gst_caps_get_structure(pyg_boxed_get(self, GstCaps), i), 
			    FALSE, FALSE);
	if (ret)
	  pygst_caps_map_add (ret, self);
	return ret;
}

/* FIXME: This syntax sucks */
static PyObject *
pygst_caps_sq_slice(PyObject *self, int start, int end)
{
	GstCaps *caps = pyg_boxed_get (self, GstCaps);
	GstCaps *ret = gst_caps_new_empty ();
	int i;

	if (start < 0)
	  start = 0;
	if (end > gst_caps_get_size (caps))
	  end = gst_caps_get_size (caps);

	for (i = start; i < end; i++)
	  gst_caps_append_structure (ret, gst_structure_copy (gst_caps_get_structure (caps, i)));
	
	return pyg_boxed_new(GST_TYPE_CAPS, ret, FALSE, TRUE);
}

static PySequenceMethods _wrap_gst_caps_tp_as_sequence = {
	pygst_caps_sq_length,
        NULL, /* not allowed for sets, use | instead of + */
        NULL, /* doesn't make sense, because it'd still be the same */
	pygst_caps_sq_item,
        pygst_caps_sq_slice, 
	NULL, /* doesn't make sense, you can only append */
	NULL, /* doesn't make sense, you can only append */
        NULL, /* doesn't make sense really, unless you use is_subset */
        NULL, /* not allowed for sets, use | instead of + */
	NULL /* doesn't make sense, because it'd still be the same */
};
%%
override-slot GstCaps.tp_dealloc
static void
_wrap_gst_caps_tp_dealloc (PyObject *self)
{
  PyGBoxed *boxed = (PyGBoxed *) self;

  if (boxed->free_on_dealloc && boxed->boxed) {
    pygst_caps_map_modified (self);
    gst_caps_free (boxed->boxed);
  }

  self->ob_type->tp_free((PyObject *)self);
}
%%
override-slot GstCaps.tp_str
static PyObject *
_wrap_gst_caps_tp_str(PyGObject *self)
{
    gchar *tmp;
    PyObject *retval;
    
    tmp = gst_caps_to_string((GstCaps*)self->obj);
    retval = PyString_FromString(tmp);
    g_free(tmp);

    return retval;
}