mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-09-08 13:18:52 +00:00
539 lines
14 KiB
C
539 lines
14 KiB
C
/* GStreamer
|
|
* Copyright (C) 2005 Stefan Kost <ensonic@users.sf.net>
|
|
*
|
|
* gstchildproxy.c: interface for multi child elements
|
|
*
|
|
* 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:gstchildproxy
|
|
* @short_description: Interface for multi child elements.
|
|
* @see_also: #GstBin
|
|
*
|
|
* This interface abstracts handling of property sets for elements with
|
|
* children. Imagine elements such as mixers or polyphonic generators. They all
|
|
* have multiple #GstPad or some kind of voice objects. Another use case are
|
|
* container elements like #GstBin.
|
|
* The element implementing the interface acts as a parent for those child
|
|
* objects.
|
|
*
|
|
* By implementing this interface the child properties can be accessed from the
|
|
* parent element by using gst_child_proxy_get() and gst_child_proxy_set().
|
|
*
|
|
* Property names are written as "child-name::property-name". The whole naming
|
|
* scheme is recursive. Thus "child1::child2::property" is valid too, if
|
|
* "child1" and "child2" implement the #GstChildProxy interface.
|
|
*/
|
|
/* FIXME-0.11:
|
|
* it would be nice to make gst_child_proxy_get_child_by_name virtual too and
|
|
* use GObject instead of GstObject. We could eventually provide the current
|
|
* implementation as a default if children are GstObjects.
|
|
* This change would allow to propose the interface for inclusion with
|
|
* glib/gobject. IMHO this is useful for GtkContainer and compound widgets too.
|
|
*/
|
|
|
|
#include "gst_private.h"
|
|
|
|
#include "gstchildproxy.h"
|
|
#include "gstmarshal.h"
|
|
#include <gobject/gvaluecollector.h>
|
|
|
|
/* signals */
|
|
enum
|
|
{
|
|
CHILD_ADDED,
|
|
CHILD_REMOVED,
|
|
LAST_SIGNAL
|
|
};
|
|
|
|
static guint signals[LAST_SIGNAL] = { 0 };
|
|
|
|
/**
|
|
* gst_child_proxy_get_child_by_name:
|
|
* @parent: the parent object to get the child from
|
|
* @name: the childs name
|
|
*
|
|
* Looks up a child element by the given name.
|
|
*
|
|
* Implementors can use #GstObject together with gst_object_get_name()
|
|
*
|
|
* Returns: the child object or %NULL if not found. Unref after usage.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
GstObject *
|
|
gst_child_proxy_get_child_by_name (GstChildProxy * parent, const gchar * name)
|
|
{
|
|
guint count, i;
|
|
GstObject *object, *result;
|
|
gchar *object_name;
|
|
|
|
g_return_val_if_fail (GST_IS_CHILD_PROXY (parent), NULL);
|
|
g_return_val_if_fail (name != NULL, NULL);
|
|
|
|
result = NULL;
|
|
|
|
count = gst_child_proxy_get_children_count (parent);
|
|
for (i = 0; i < count; i++) {
|
|
gboolean eq;
|
|
|
|
if (!(object = gst_child_proxy_get_child_by_index (parent, i)))
|
|
continue;
|
|
|
|
object_name = gst_object_get_name (object);
|
|
if (object_name == NULL) {
|
|
g_warning ("child %u of parent %s has no name", i,
|
|
GST_OBJECT_NAME (parent));
|
|
goto next;
|
|
}
|
|
eq = g_str_equal (object_name, name);
|
|
g_free (object_name);
|
|
|
|
if (eq) {
|
|
result = object;
|
|
break;
|
|
}
|
|
next:
|
|
gst_object_unref (object);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* gst_child_proxy_get_child_by_index:
|
|
* @parent: the parent object to get the child from
|
|
* @index: the childs position in the child list
|
|
*
|
|
* Fetches a child by its number.
|
|
*
|
|
* Returns: the child object or %NULL if not found (index too high). Unref
|
|
* after usage.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
GstObject *
|
|
gst_child_proxy_get_child_by_index (GstChildProxy * parent, guint index)
|
|
{
|
|
g_return_val_if_fail (GST_IS_CHILD_PROXY (parent), NULL);
|
|
|
|
return (GST_CHILD_PROXY_GET_INTERFACE (parent)->get_child_by_index (parent,
|
|
index));
|
|
}
|
|
|
|
/**
|
|
* gst_child_proxy_get_children_count:
|
|
* @parent: the parent object
|
|
*
|
|
* Gets the number of child objects this parent contains.
|
|
*
|
|
* Returns: the number of child objects
|
|
*
|
|
* MT safe.
|
|
*/
|
|
guint
|
|
gst_child_proxy_get_children_count (GstChildProxy * parent)
|
|
{
|
|
g_return_val_if_fail (GST_IS_CHILD_PROXY (parent), 0);
|
|
|
|
return (GST_CHILD_PROXY_GET_INTERFACE (parent)->get_children_count (parent));
|
|
}
|
|
|
|
/**
|
|
* gst_child_proxy_lookup:
|
|
* @object: object to lookup the property in
|
|
* @name: name of the property to look up
|
|
* @target: pointer to a #GstObject that takes the real object to set property on
|
|
* @pspec: pointer to take the #GParamSpec describing the property
|
|
*
|
|
* Looks up which object and #GParamSpec would be effected by the given @name.
|
|
*
|
|
* Returns: TRUE if @target and @pspec could be found. FALSE otherwise. In that
|
|
* case the values for @pspec and @target are not modified. Unref @target after
|
|
* usage.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
gboolean
|
|
gst_child_proxy_lookup (GstObject * object, const gchar * name,
|
|
GstObject ** target, GParamSpec ** pspec)
|
|
{
|
|
gboolean res = FALSE;
|
|
gchar **names, **current;
|
|
|
|
g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
|
|
g_return_val_if_fail (name != NULL, FALSE);
|
|
|
|
gst_object_ref (object);
|
|
|
|
current = names = g_strsplit (name, "::", -1);
|
|
while (current[1]) {
|
|
GstObject *next;
|
|
|
|
if (!GST_IS_CHILD_PROXY (object)) {
|
|
GST_INFO
|
|
("object %s is not a parent, so you cannot request a child by name %s",
|
|
GST_OBJECT_NAME (object), current[0]);
|
|
break;
|
|
}
|
|
next = gst_child_proxy_get_child_by_name (GST_CHILD_PROXY (object),
|
|
current[0]);
|
|
if (!next) {
|
|
GST_INFO ("no such object %s", current[0]);
|
|
break;
|
|
}
|
|
gst_object_unref (object);
|
|
object = next;
|
|
current++;
|
|
}
|
|
if (current[1] == NULL) {
|
|
GParamSpec *spec =
|
|
g_object_class_find_property (G_OBJECT_GET_CLASS (object), current[0]);
|
|
if (spec == NULL) {
|
|
GST_INFO ("no param spec named %s", current[0]);
|
|
} else {
|
|
if (pspec)
|
|
*pspec = spec;
|
|
if (target) {
|
|
gst_object_ref (object);
|
|
*target = object;
|
|
}
|
|
res = TRUE;
|
|
}
|
|
}
|
|
gst_object_unref (object);
|
|
g_strfreev (names);
|
|
return res;
|
|
}
|
|
|
|
/**
|
|
* gst_child_proxy_get_property:
|
|
* @object: object to query
|
|
* @name: name of the property
|
|
* @value: a #GValue that should take the result.
|
|
*
|
|
* Gets a single property using the GstChildProxy mechanism.
|
|
* You are responsible for for freeing it by calling g_value_unset()
|
|
*/
|
|
void
|
|
gst_child_proxy_get_property (GstObject * object, const gchar * name,
|
|
GValue * value)
|
|
{
|
|
GParamSpec *pspec;
|
|
GstObject *target;
|
|
|
|
g_return_if_fail (GST_IS_OBJECT (object));
|
|
g_return_if_fail (name != NULL);
|
|
g_return_if_fail (G_IS_VALUE (value));
|
|
|
|
if (!gst_child_proxy_lookup (object, name, &target, &pspec))
|
|
goto not_found;
|
|
|
|
g_object_get_property (G_OBJECT (target), pspec->name, value);
|
|
gst_object_unref (target);
|
|
|
|
return;
|
|
|
|
not_found:
|
|
{
|
|
g_warning ("no property %s in object %s", name, GST_OBJECT_NAME (object));
|
|
return;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_child_proxy_get_valist:
|
|
* @object: the object to query
|
|
* @first_property_name: name of the first property to get
|
|
* @var_args: return location for the first property, followed optionally by more name/return location pairs, followed by NULL
|
|
*
|
|
* Gets properties of the parent object and its children.
|
|
*/
|
|
void
|
|
gst_child_proxy_get_valist (GstObject * object,
|
|
const gchar * first_property_name, va_list var_args)
|
|
{
|
|
const gchar *name;
|
|
gchar *error = NULL;
|
|
GValue value = { 0, };
|
|
GParamSpec *pspec;
|
|
GstObject *target;
|
|
|
|
g_return_if_fail (G_IS_OBJECT (object));
|
|
|
|
name = first_property_name;
|
|
|
|
/* iterate over pairs */
|
|
while (name) {
|
|
if (!gst_child_proxy_lookup (object, name, &target, &pspec))
|
|
goto not_found;
|
|
|
|
g_value_init (&value, pspec->value_type);
|
|
g_object_get_property (G_OBJECT (target), pspec->name, &value);
|
|
gst_object_unref (target);
|
|
|
|
G_VALUE_LCOPY (&value, var_args, 0, &error);
|
|
if (error)
|
|
goto cant_copy;
|
|
g_value_unset (&value);
|
|
name = va_arg (var_args, gchar *);
|
|
}
|
|
return;
|
|
|
|
not_found:
|
|
{
|
|
g_warning ("no property %s in object %s", name, GST_OBJECT_NAME (object));
|
|
return;
|
|
}
|
|
cant_copy:
|
|
{
|
|
g_warning ("error copying value %s in object %s: %s", pspec->name,
|
|
GST_OBJECT_NAME (object), error);
|
|
g_value_unset (&value);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_child_proxy_get:
|
|
* @object: the parent object
|
|
* @first_property_name: name of the first property to get
|
|
* @...: return location for the first property, followed optionally by more name/return location pairs, followed by NULL
|
|
*
|
|
* Gets properties of the parent object and its children.
|
|
*/
|
|
void
|
|
gst_child_proxy_get (GstObject * object, const gchar * first_property_name, ...)
|
|
{
|
|
va_list var_args;
|
|
|
|
g_return_if_fail (GST_IS_OBJECT (object));
|
|
|
|
va_start (var_args, first_property_name);
|
|
gst_child_proxy_get_valist (object, first_property_name, var_args);
|
|
va_end (var_args);
|
|
}
|
|
|
|
/**
|
|
* gst_child_proxy_set_property:
|
|
* @object: the parent object
|
|
* @name: name of the property to set
|
|
* @value: new #GValue for the property
|
|
*
|
|
* Sets a single property using the GstChildProxy mechanism.
|
|
*/
|
|
void
|
|
gst_child_proxy_set_property (GstObject * object, const gchar * name,
|
|
const GValue * value)
|
|
{
|
|
GParamSpec *pspec;
|
|
GstObject *target;
|
|
|
|
g_return_if_fail (GST_IS_OBJECT (object));
|
|
g_return_if_fail (name != NULL);
|
|
g_return_if_fail (G_IS_VALUE (value));
|
|
|
|
if (!gst_child_proxy_lookup (object, name, &target, &pspec))
|
|
goto not_found;
|
|
|
|
g_object_set_property (G_OBJECT (target), pspec->name, value);
|
|
gst_object_unref (target);
|
|
return;
|
|
|
|
not_found:
|
|
{
|
|
g_warning ("cannot set property %s on object %s", name,
|
|
GST_OBJECT_NAME (object));
|
|
return;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_child_proxy_set_valist:
|
|
* @object: the parent object
|
|
* @first_property_name: name of the first property to set
|
|
* @var_args: value for the first property, followed optionally by more name/value pairs, followed by NULL
|
|
*
|
|
* Sets properties of the parent object and its children.
|
|
*/
|
|
void
|
|
gst_child_proxy_set_valist (GstObject * object,
|
|
const gchar * first_property_name, va_list var_args)
|
|
{
|
|
const gchar *name;
|
|
gchar *error = NULL;
|
|
GValue value = { 0, };
|
|
GParamSpec *pspec;
|
|
GstObject *target;
|
|
|
|
g_return_if_fail (G_IS_OBJECT (object));
|
|
|
|
name = first_property_name;
|
|
|
|
/* iterate over pairs */
|
|
while (name) {
|
|
if (!gst_child_proxy_lookup (object, name, &target, &pspec))
|
|
goto not_found;
|
|
|
|
#if GLIB_CHECK_VERSION(2,23,3)
|
|
G_VALUE_COLLECT_INIT (&value, pspec->value_type, var_args,
|
|
G_VALUE_NOCOPY_CONTENTS, &error);
|
|
#else
|
|
g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (pspec));
|
|
G_VALUE_COLLECT (&value, var_args, G_VALUE_NOCOPY_CONTENTS, &error);
|
|
#endif
|
|
if (error)
|
|
goto cant_copy;
|
|
|
|
g_object_set_property (G_OBJECT (target), pspec->name, &value);
|
|
gst_object_unref (target);
|
|
|
|
g_value_unset (&value);
|
|
name = va_arg (var_args, gchar *);
|
|
}
|
|
return;
|
|
|
|
not_found:
|
|
{
|
|
g_warning ("no property %s in object %s", name, GST_OBJECT_NAME (object));
|
|
return;
|
|
}
|
|
cant_copy:
|
|
{
|
|
g_warning ("error copying value %s in object %s: %s", pspec->name,
|
|
GST_OBJECT_NAME (object), error);
|
|
g_value_unset (&value);
|
|
gst_object_unref (target);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_child_proxy_set:
|
|
* @object: the parent object
|
|
* @first_property_name: name of the first property to set
|
|
* @...: value for the first property, followed optionally by more name/value pairs, followed by NULL
|
|
*
|
|
* Sets properties of the parent object and its children.
|
|
*/
|
|
void
|
|
gst_child_proxy_set (GstObject * object, const gchar * first_property_name, ...)
|
|
{
|
|
va_list var_args;
|
|
|
|
g_return_if_fail (GST_IS_OBJECT (object));
|
|
|
|
va_start (var_args, first_property_name);
|
|
gst_child_proxy_set_valist (object, first_property_name, var_args);
|
|
va_end (var_args);
|
|
}
|
|
|
|
/**
|
|
* gst_child_proxy_child_added:
|
|
* @object: the parent object
|
|
* @child: the newly added child
|
|
*
|
|
* Emits the "child-added" signal.
|
|
*/
|
|
void
|
|
gst_child_proxy_child_added (GstObject * object, GstObject * child)
|
|
{
|
|
g_signal_emit (G_OBJECT (object), signals[CHILD_ADDED], 0, child);
|
|
}
|
|
|
|
/**
|
|
* gst_child_proxy_child_removed:
|
|
* @object: the parent object
|
|
* @child: the removed child
|
|
*
|
|
* Emits the "child-removed" signal.
|
|
*/
|
|
void
|
|
gst_child_proxy_child_removed (GstObject * object, GstObject * child)
|
|
{
|
|
g_signal_emit (G_OBJECT (object), signals[CHILD_REMOVED], 0, child);
|
|
}
|
|
|
|
/* gobject methods */
|
|
|
|
static void
|
|
gst_child_proxy_base_init (gpointer g_class)
|
|
{
|
|
static gboolean initialized = FALSE;
|
|
|
|
if (!initialized) {
|
|
/* create interface signals and properties here. */
|
|
/**
|
|
* GstChildProxy::child-added:
|
|
* @child_proxy: the #GstChildProxy
|
|
* @object: the #GObject that was added
|
|
*
|
|
* Will be emitted after the @object was added to the @child_proxy.
|
|
*/
|
|
/* FIXME 0.11: use GST_TYPE_OBJECT as GstChildProxy only
|
|
* supports GstObjects */
|
|
signals[CHILD_ADDED] =
|
|
g_signal_new ("child-added", G_TYPE_FROM_CLASS (g_class),
|
|
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstChildProxyInterface,
|
|
child_added), NULL, NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1,
|
|
G_TYPE_OBJECT);
|
|
|
|
/**
|
|
* GstChildProxy::child-removed:
|
|
* @child_proxy: the #GstChildProxy
|
|
* @object: the #GObject that was removed
|
|
*
|
|
* Will be emitted after the @object was removed from the @child_proxy.
|
|
*/
|
|
/* FIXME 0.11: use GST_TYPE_OBJECT as GstChildProxy only
|
|
* supports GstObjects */
|
|
signals[CHILD_REMOVED] =
|
|
g_signal_new ("child-removed", G_TYPE_FROM_CLASS (g_class),
|
|
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstChildProxyInterface,
|
|
child_removed), NULL, NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE,
|
|
1, G_TYPE_OBJECT);
|
|
|
|
initialized = TRUE;
|
|
}
|
|
}
|
|
|
|
GType
|
|
gst_child_proxy_get_type (void)
|
|
{
|
|
static volatile gsize type = 0;
|
|
|
|
if (g_once_init_enter (&type)) {
|
|
GType _type;
|
|
static const GTypeInfo info = {
|
|
sizeof (GstChildProxyInterface),
|
|
gst_child_proxy_base_init, /* base_init */
|
|
NULL, /* base_finalize */
|
|
NULL, /* class_init */
|
|
NULL, /* class_finalize */
|
|
NULL, /* class_data */
|
|
0,
|
|
0, /* n_preallocs */
|
|
NULL /* instance_init */
|
|
};
|
|
|
|
_type =
|
|
g_type_register_static (G_TYPE_INTERFACE, "GstChildProxy", &info, 0);
|
|
|
|
g_type_interface_add_prerequisite (_type, GST_TYPE_OBJECT);
|
|
g_once_init_leave (&type, (gsize) _type);
|
|
}
|
|
return type;
|
|
}
|