/* GStreamer

 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>

 *                    2000 Wim Taymans <wtay@chello.be>

 *                    2003 Benjamin Otte <in7y118@public.uni-hamburg.de>

 *

 * gstelementfactory.c: GstElementFactory object, support routines

 *

 * 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.

 */

/**

 * SECTION:gstelementfactory

 * @short_description: Create GstElements from a factory

 * @see_also: #GstElement, #GstPlugin, #GstPluginFeature, #GstPadTemplate.

 *

 * #GstElementFactory is used to create instances of elements. A

 * GstElementfactory can be added to a #GstPlugin as it is also a

 * #GstPluginFeature.

 *

 * Use the gst_element_factory_find() and gst_element_factory_create()

 * functions to create element instances or use gst_element_factory_make() as a

 * convenient shortcut.

 *

 * The following code example shows you how to create a GstFileSrc element.

 *

 * <example>

 * <title>Using an element factory</title>

 * <programlisting language="c">

 *   #include <gst/gst.h>

 *   

 *   GstElement *src;

 *   GstElementFactory *srcfactory;

 *   

 *   gst_init (&argc, &argv);

 *   

 *   srcfactory = gst_element_factory_find ("filesrc");

 *   g_return_if_fail (srcfactory != NULL);

 *   src = gst_element_factory_create (srcfactory, "src");

 *   g_return_if_fail (src != NULL);

 *   ...

 * </programlisting>

 * </example>

 *

 * Last reviewed on 2005-11-23 (0.9.5)

 */

#include "gst_private.h"

#include "gstelement.h"

#include "gstinfo.h"

#include "gsturi.h"

#include "gstregistry.h"

#include "glib-compat-private.h"

GST_DEBUG_CATEGORY_STATIC (element_factory_debug);

#define GST_CAT_DEFAULT element_factory_debug

static void gst_element_factory_class_init (GstElementFactoryClass * klass);

static void gst_element_factory_init (GstElementFactory * factory);

static void gst_element_factory_finalize (GObject * object);

void __gst_element_details_clear (GstElementDetails * dp);

static void gst_element_factory_cleanup (GstElementFactory * factory);

static GstPluginFeatureClass *parent_class = NULL;

/* static guint gst_element_factory_signals[LAST_SIGNAL] = { 0 }; */

/* this is defined in gstelement.c */

extern GQuark _gst_elementclass_factory;

#define _do_init \

{ \

  GST_DEBUG_CATEGORY_INIT (element_factory_debug, "GST_ELEMENT_FACTORY", \

      GST_DEBUG_BOLD | GST_DEBUG_FG_WHITE | GST_DEBUG_BG_RED, \

      "element factories keep information about installed elements"); \

}

G_DEFINE_TYPE_WITH_CODE (GstElementFactory, gst_element_factory,

    GST_TYPE_PLUGIN_FEATURE, _do_init);

static void

gst_element_factory_class_init (GstElementFactoryClass * klass)

{

  GObjectClass *gobject_class = (GObjectClass *) klass;

  parent_class = g_type_class_peek_parent (klass);

  gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_element_factory_finalize);

}

static void

gst_element_factory_init (GstElementFactory * factory)

{

  factory->staticpadtemplates = NULL;

  factory->numpadtemplates = 0;

  factory->uri_type = GST_URI_UNKNOWN;

  factory->uri_protocols = NULL;

  factory->interfaces = NULL;

}

static void

gst_element_factory_finalize (GObject * object)

{

  GstElementFactory *factory = GST_ELEMENT_FACTORY (object);

  gst_element_factory_cleanup (factory);

  G_OBJECT_CLASS (parent_class)->finalize (object);

}

/**

 * gst_element_factory_find:

 * @name: name of factory to find

 *

 * Search for an element factory of the given name. Refs the returned

 * element factory; caller is responsible for unreffing.

 *

 * Returns: #GstElementFactory if found, NULL otherwise

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstElementFactory *

gst_element_factory_find (const gchar * name)

{

  GstPluginFeature *feature;

  g_return_val_if_fail (name != NULL, NULL);

  feature = gst_registry_find_feature (gst_registry_get_default (), name,

      GST_TYPE_ELEMENT_FACTORY);

  if (feature)

    return GST_ELEMENT_FACTORY (feature);

  /* this isn't an error, for instance when you query if an element factory is

   * present */

  GST_LOG ("no such element factory \"%s\"", name);

  return NULL;

}

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

__gst_element_details_clear (GstElementDetails * dp)

{

  g_free (dp->longname);

  g_free (dp->klass);

  g_free (dp->description);

  g_free (dp->author);

  memset (dp, 0, sizeof (GstElementDetails));

}

#define VALIDATE_SET(__dest, __src, __entry)                            \

G_STMT_START {                                                          \

  if (g_utf8_validate (__src->__entry, -1, NULL)) {                     \

    __dest->__entry = g_strdup (__src->__entry);                        \

  } else {                                                              \

    g_warning ("Invalid UTF-8 in " G_STRINGIFY (__entry) ": %s",        \

        __src->__entry);                                                \

    __dest->__entry = g_strdup ("[ERROR: invalid UTF-8]");              \

  }                                                                     \

}G_STMT_END

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

__gst_element_details_set (GstElementDetails * dest,

    const GstElementDetails * src)

{

  VALIDATE_SET (dest, src, longname);

  VALIDATE_SET (dest, src, klass);

  VALIDATE_SET (dest, src, description);

  VALIDATE_SET (dest, src, author);

}

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

__gst_element_details_copy (GstElementDetails * dest,

    const GstElementDetails * src)

{

  __gst_element_details_clear (dest);

  __gst_element_details_set (dest, src);

}

static void

gst_element_factory_cleanup (GstElementFactory * factory)

{

  GList *item;

  __gst_element_details_clear (&factory->details);

  if (factory->type) {

    factory->type = G_TYPE_INVALID;

  }

  for (item = factory->staticpadtemplates; item; item = item->next) {

    GstStaticPadTemplate *templ = item->data;

    GstCaps *caps = (GstCaps *) & (templ->static_caps);

    g_free ((gchar *) templ->static_caps.string);

    /* FIXME: this is not threadsafe */

    if (caps->refcount == 1) {

      GstStructure *structure;

      guint i;

      for (i = 0; i < caps->structs->len; i++) {

        structure = (GstStructure *) gst_caps_get_structure (caps, i);

        gst_structure_set_parent_refcount (structure, NULL);

        gst_structure_free (structure);

      }

      g_ptr_array_free (caps->structs, TRUE);

      caps->refcount = 0;

    }

    g_free (templ);

  }

  g_list_free (factory->staticpadtemplates);

  factory->staticpadtemplates = NULL;

  factory->numpadtemplates = 0;

  factory->uri_type = GST_URI_UNKNOWN;

  if (factory->uri_protocols) {

    g_strfreev (factory->uri_protocols);

    factory->uri_protocols = NULL;

  }

  g_list_foreach (factory->interfaces, (GFunc) g_free, NULL);

  g_list_free (factory->interfaces);

  factory->interfaces = NULL;

}

/**

 * gst_element_register:

 * @plugin: #GstPlugin to register the element with, or NULL for a static

 * element (note that passing NULL only works in GStreamer 0.10.13 and later)

 * @name: name of elements of this type

 * @rank: rank of element (higher rank means more importance when autoplugging)

 * @type: GType of element to register

 *

 * Create a new elementfactory capable of instantiating objects of the

 * @type and add the factory to @plugin.

 *

 * Returns: TRUE, if the registering succeeded, FALSE on error

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

gboolean

gst_element_register (GstPlugin * plugin, const gchar * name, guint rank,

    GType type)

{

  GstPluginFeature *existing_feature;

  GstRegistry *registry;

  GstElementFactory *factory;

  GType *interfaces;

  guint n_interfaces, i;

  GstElementClass *klass;

  GList *item;

  g_return_val_if_fail (name != NULL, FALSE);

  g_return_val_if_fail (g_type_is_a (type, GST_TYPE_ELEMENT), FALSE);

  registry = gst_registry_get_default ();

  /* check if feature already exists, if it exists there is no need to update it

   * when the registry is getting updated, outdated plugins and all there

   * feature are removed and readded.

   */

  existing_feature = gst_registry_lookup_feature (registry, name);

  if (existing_feature) {

    GST_DEBUG_OBJECT (registry, "update existing feature %p (%s)",

        existing_feature, name);

    factory = GST_ELEMENT_FACTORY_CAST (existing_feature);

    factory->type = type;

    existing_feature->loaded = TRUE;

    g_type_set_qdata (type, _gst_elementclass_factory, factory);

    gst_object_unref (existing_feature);

    return TRUE;

  }

  factory =

      GST_ELEMENT_FACTORY_CAST (g_object_new (GST_TYPE_ELEMENT_FACTORY, NULL));

  gst_plugin_feature_set_name (GST_PLUGIN_FEATURE_CAST (factory), name);

  GST_LOG_OBJECT (factory, "Created new elementfactory for type %s",

      g_type_name (type));

  klass = GST_ELEMENT_CLASS (g_type_class_ref (type));

  if ((klass->details.longname == NULL) ||

      (klass->details.klass == NULL) || (klass->details.author == NULL))

    goto detailserror;

  factory->type = type;

  __gst_element_details_copy (&factory->details, &klass->details);

  for (item = klass->padtemplates; item; item = item->next) {

    GstPadTemplate *templ = item->data;

    GstStaticPadTemplate *newt;

    newt = g_new0 (GstStaticPadTemplate, 1);

    newt->name_template = g_intern_string (templ->name_template);

    newt->direction = templ->direction;

    newt->presence = templ->presence;

    newt->static_caps.string = gst_caps_to_string (templ->caps);

    factory->staticpadtemplates =

        g_list_append (factory->staticpadtemplates, newt);

  }

  factory->numpadtemplates = klass->numpadtemplates;

  g_type_set_qdata (type, _gst_elementclass_factory, factory);

  /* special stuff for URI handling */

  if (g_type_is_a (type, GST_TYPE_URI_HANDLER)) {

    GstURIHandlerInterface *iface = (GstURIHandlerInterface *)

        g_type_interface_peek (klass, GST_TYPE_URI_HANDLER);

    if (!iface || (!iface->get_type && !iface->get_type_full) ||

        (!iface->get_protocols && !iface->get_protocols_full))

      goto urierror;

    if (iface->get_type)

      factory->uri_type = iface->get_type ();

    else if (iface->get_type_full)

      factory->uri_type = iface->get_type_full (factory->type);

    if (!GST_URI_TYPE_IS_VALID (factory->uri_type))

      goto urierror;

    if (iface->get_protocols)

      factory->uri_protocols = g_strdupv (iface->get_protocols ());

    else if (iface->get_protocols_full)

      factory->uri_protocols = iface->get_protocols_full (factory->type);

    if (!factory->uri_protocols)

      goto urierror;

  }

  interfaces = g_type_interfaces (type, &n_interfaces);

  for (i = 0; i < n_interfaces; i++) {

    __gst_element_factory_add_interface (factory, g_type_name (interfaces[i]));

  }

  g_free (interfaces);

  if (plugin && plugin->desc.name) {

    GST_PLUGIN_FEATURE_CAST (factory)->plugin_name = plugin->desc.name;

  } else {

    GST_PLUGIN_FEATURE_CAST (factory)->plugin_name = "NULL";

  }

  gst_plugin_feature_set_rank (GST_PLUGIN_FEATURE_CAST (factory), rank);

  GST_PLUGIN_FEATURE_CAST (factory)->loaded = TRUE;

  gst_registry_add_feature (registry, GST_PLUGIN_FEATURE_CAST (factory));

  return TRUE;

  /* ERRORS */

urierror:

  {

    GST_WARNING_OBJECT (factory, "error with uri handler!");

    gst_element_factory_cleanup (factory);

    return FALSE;

  }

detailserror:

  {

    GST_WARNING_OBJECT (factory,

        "The GstElementDetails don't seem to have been set properly");

    gst_element_factory_cleanup (factory);

    return FALSE;

  }

}

/**

 * gst_element_factory_create:

 * @factory: factory to instantiate

 * @name: name of new element

 *

 * Create a new element of the type defined by the given elementfactory.

 * It will be given the name supplied, since all elements require a name as

 * their first argument.

 *

 * Returns: new #GstElement or NULL if the element couldn't be created

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstElement *

gst_element_factory_create (GstElementFactory * factory, const gchar * name)

{

  GstElement *element;

  GstElementClass *oclass;

  GstElementFactory *newfactory;

  g_return_val_if_fail (factory != NULL, NULL);

  newfactory =

      GST_ELEMENT_FACTORY (gst_plugin_feature_load (GST_PLUGIN_FEATURE

          (factory)));

  if (newfactory == NULL)

    goto load_failed;

  factory = newfactory;

  if (name)

    GST_INFO ("creating element \"%s\" named \"%s\"",

        GST_PLUGIN_FEATURE_NAME (factory), GST_STR_NULL (name));

  else

    GST_INFO ("creating element \"%s\"", GST_PLUGIN_FEATURE_NAME (factory));

  if (factory->type == 0)

    goto no_type;

  /* create an instance of the element, cast so we don't assert on NULL */

  element = GST_ELEMENT_CAST (g_object_new (factory->type, NULL));

  if (G_UNLIKELY (element == NULL))

    goto no_element;

  /* fill in the pointer to the factory in the element class. The

   * class will not be unreffed currently. 

   * Be thread safe as there might be 2 threads creating the first instance of

   * an element at the same moment

   */

  oclass = GST_ELEMENT_GET_CLASS (element);

  if (!g_atomic_pointer_compare_and_exchange (

          (gpointer) & oclass->elementfactory, NULL, factory))

    gst_object_unref (factory);

  if (name)

    gst_object_set_name (GST_OBJECT_CAST (element), name);

  GST_DEBUG ("created element \"%s\"", GST_PLUGIN_FEATURE_NAME (factory));

  return element;

  /* ERRORS */

load_failed:

  {

    GST_WARNING_OBJECT (factory,

        "loading plugin containing feature %s returned NULL!", name);

    return NULL;

  }

no_type:

  {

    GST_WARNING_OBJECT (factory, "factory has no type");

    gst_object_unref (factory);

    return NULL;

  }

no_element:

  {

    GST_WARNING_OBJECT (factory, "could not create element");

    gst_object_unref (factory);

    return NULL;

  }

}

/**

 * gst_element_factory_make:

 * @factoryname: a named factory to instantiate

 * @name: name of new element

 *

 * Create a new element of the type defined by the given element factory.

 * If name is NULL, then the element will receive a guaranteed unique name,

 * consisting of the element factory name and a number.

 * If name is given, it will be given the name supplied.

 *

 * Returns: new #GstElement or NULL if unable to create element

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GstElement *

gst_element_factory_make (const gchar * factoryname, const gchar * name)

{

  GstElementFactory *factory;

  GstElement *element;

  g_return_val_if_fail (factoryname != NULL, NULL);

  GST_LOG ("gstelementfactory: make \"%s\" \"%s\"",

      factoryname, GST_STR_NULL (name));

  factory = gst_element_factory_find (factoryname);

  if (factory == NULL)

    goto no_factory;

  GST_LOG_OBJECT (factory, "found factory %p", factory);

  element = gst_element_factory_create (factory, name);

  if (element == NULL)

    goto create_failed;

  gst_object_unref (factory);

  return element;

  /* ERRORS */

no_factory:

  {

    GST_INFO ("no such element factory \"%s\"!", factoryname);

    return NULL;

  }

create_failed: