gstreamer/gst/gstelementfactory.c

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/* Gnome-Streamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
*
* 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.
*/
#include <gst/gstelement.h>
/* global list of registered elementfactories */
GList* _gst_elementfactories;
void _gst_elementfactory_initialize() {
_gst_elementfactories = NULL;
}
/**
* gst_elementfactory_register:
* @elementfactory: factory to register
*
* Adds the elementfactory to the global list, so it can be retrieved by
* name.
*/
void gst_elementfactory_register(GstElementFactory *elementfactory) {
g_return_if_fail(elementfactory != NULL);
_gst_elementfactories = g_list_prepend(_gst_elementfactories,elementfactory);
}
/**
* gst_elementfactory_find:
* @name: name of factory to find
*
* Search for an elementfactory of the given name.
*
* Returns: #GstElementFactory if found, NULL otherwise
*/
GstElementFactory *gst_elementfactory_find(gchar *name) {
GList *walk = _gst_elementfactories;
GstElementFactory *factory;
while (walk) {
factory = (GstElementFactory *)(walk->data);
if (!strcmp(name,factory->name))
return factory;
walk = g_list_next(walk);
}
return NULL;
}
/**
* gst_elementfactory_get_list:
*
* Get the global list of elementfactories.
*
* Returns: <type>GList</type> of type #GstElementFactory
*/
GList *gst_elementfactory_get_list() {
return _gst_elementfactories;
}
/**
* gst_elementfactory_new:
* @name: name of new elementfactory
* @type: GtkType of new element
* @details: #GstElementDetails structure with element details
*
* Create a new elementfactory capable of insantiating objects of the
* given type.
*
* Returns: new elementfactory
*/
GstElementFactory *gst_elementfactory_new(gchar *name,GtkType type,
GstElementDetails *details) {
GstElementFactory *factory = g_new0(GstElementFactory, 1);
factory->name = g_strdup(name);
factory->type = type;
factory->details = details;
return factory;
}
/**
* gst_elementfactory_create:
* @factory: factory to instantiate
* @name: name of new element
*
* Create a new element of the type defined by the given elementfactory.
* It wll be given the name supplied, since all elements require a name as
* their first argument.
*
* Returns: new #GstElement
*/
GstElement *gst_elementfactory_create(GstElementFactory *factory,
gchar *name) {
GstElement *element;
GstElementClass *oclass;
g_return_val_if_fail(factory != NULL, NULL);
g_return_val_if_fail(factory->type != 0, NULL);
// create an instance of the element
element = GST_ELEMENT(gtk_type_new(factory->type));
g_assert(element != NULL);
// attempt to set the elemenfactory class pointer if necessary
oclass = GST_ELEMENT_CLASS(GTK_OBJECT(element)->klass);
if (oclass->elementfactory == NULL)
oclass->elementfactory = factory;
gst_element_set_name(GST_ELEMENT(element),name);
return element;
}
GstElement *gst_elementfactory_make(gchar *factoryname,gchar *name) {
GstElementFactory *factory;
GstElement *element;
factory = gst_elementfactory_find(factoryname);
if (factory == NULL) return NULL;
element = gst_elementfactory_create(factory,name);
return element;
}