gstreamer/gst/gstpluginfeature.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstpluginfeature.c: Abstract base class for all plugin features
*
* 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:gstpluginfeature
* @short_description: Base class for contents of a GstPlugin
* @see_also: #GstPlugin
*
* This is a base class for anything that can be added to a #GstPlugin.
*/
#include "gst_private.h"
#include "gstpluginfeature.h"
#include "gstplugin.h"
#include "gstregistry.h"
#include "gstinfo.h"
#include <string.h>
static void gst_plugin_feature_class_init (GstPluginFeatureClass * klass);
static void gst_plugin_feature_init (GstPluginFeature * feature);
static void gst_plugin_feature_finalize (GObject * object);
/* static guint gst_plugin_feature_signals[LAST_SIGNAL] = { 0 }; */
G_DEFINE_ABSTRACT_TYPE (GstPluginFeature, gst_plugin_feature, GST_TYPE_OBJECT);
GstObjectClass *parent_class = NULL;
static void
gst_plugin_feature_class_init (GstPluginFeatureClass * klass)
{
parent_class = g_type_class_ref (GST_TYPE_OBJECT);
G_OBJECT_CLASS (klass)->finalize =
GST_DEBUG_FUNCPTR (gst_plugin_feature_finalize);
}
static void
gst_plugin_feature_init (GstPluginFeature * feature)
{
}
static void
gst_plugin_feature_finalize (GObject * object)
{
GstPluginFeature *feature = GST_PLUGIN_FEATURE (object);
GST_DEBUG ("finalizing feature %p", feature);
g_free (feature->name);
g_free (feature->plugin_name);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
/**
* gst_plugin_feature_load:
* @feature: the plugin feature to check
*
* Loads the plugin containing @feature if it's not already loaded. @feature is
* unaffected; use the return value instead.
*
* Normally this function is used like this:
*
* <programlisting>
* GstPluginFeature *loaded_feature;
* loaded_feature = gst_plugin_feature_load (feature);
*
* // presumably, we're no longer interested in the potentially-unloaded feature
* gst_object_unref (feature);
* feature = loaded_feature;
* </programlisting>
*
* Returns: A reference to the loaded feature, or NULL on error.
*/
GstPluginFeature *
gst_plugin_feature_load (GstPluginFeature * feature)
{
GstPlugin *plugin;
GstPluginFeature *real_feature;
g_return_val_if_fail (feature != NULL, FALSE);
g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), FALSE);
GST_DEBUG ("loading plugin for feature %p", feature);
if (feature->loaded)
return feature;
GST_DEBUG ("loading plugin %s", feature->plugin_name);
plugin = gst_plugin_load_by_name (feature->plugin_name);
if (!plugin) {
g_critical ("Failed to load plugin containing feature '%s'.",
GST_PLUGIN_FEATURE_NAME (feature));
return NULL;
}
GST_DEBUG ("loaded plugin %s", feature->plugin_name);
gst_object_unref (plugin);
real_feature =
gst_registry_lookup_feature (gst_registry_get_default (), feature->name);
if (real_feature == NULL) {
g_critical
("Loaded plugin containing feature '%s', but feature disappeared.",
feature->name);
}
return real_feature;
}
gboolean
gst_plugin_feature_type_name_filter (GstPluginFeature * feature,
GstTypeNameData * data)
{
return ((data->type == 0 || data->type == G_OBJECT_TYPE (feature)) &&
(data->name == NULL
|| !strcmp (data->name, GST_PLUGIN_FEATURE_NAME (feature))));
}
/**
* gst_plugin_feature_set_name:
* @feature: a feature
* @name: the name to set
*
* Sets the name of a plugin feature. The name uniquely identifies a feature
* within all features of the same type. Renaming a plugin feature is not
* allowed. A copy is made of the name so you should free the supplied @name
* after calling this function.
*/
void
gst_plugin_feature_set_name (GstPluginFeature * feature, const gchar * name)
{
g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature));
g_return_if_fail (name != NULL);
if (feature->name) {
g_return_if_fail (strcmp (feature->name, name) == 0);
} else {
feature->name = g_strdup (name);
}
gst_object_set_name (GST_OBJECT (feature), feature->name);
}
/**
* gst_plugin_feature_get_name:
* @feature: a feature
*
* Gets the name of a plugin feature.
*
* Returns: the name
*/
G_CONST_RETURN gchar *
gst_plugin_feature_get_name (GstPluginFeature * feature)
{
g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), NULL);
return feature->name;
}
/**
* gst_plugin_feature_set_rank:
* @feature: feature to rank
* @rank: rank value - higher number means more priority rank
*
* Specifies a rank for a plugin feature, so that autoplugging uses
* the most appropriate feature.
*/
void
gst_plugin_feature_set_rank (GstPluginFeature * feature, guint rank)
{
g_return_if_fail (feature != NULL);
g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature));
feature->rank = rank;
}
/**
* gst_plugin_feature_get rank:
* @feature: a feature
*
* Gets the rank of a plugin feature.
*
* Returns: The rank of the feature
*/
guint
gst_plugin_feature_get_rank (GstPluginFeature * feature)
{
g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), GST_RANK_NONE);
return feature->rank;
}
/**
* gst_plugin_feature_list_free:
* @list: list of #GstPluginFeature
*
* Unrefs each member of @list, then frees the list.
*/
void
gst_plugin_feature_list_free (GList * list)
{
GList *g;
for (g = list; g; g = g->next) {
GstPluginFeature *feature = GST_PLUGIN_FEATURE (g->data);
gst_object_unref (feature);
}
g_list_free (list);
}