bin: add "deep-element-added" and "deep-element-removed" signals

This means applications and bin sub-classes can easily track when
a new child element is added to the pipeline sub-hierarchy or
removed.

Currently doesn't signal deep added/removed for elements inside
a bin if a bin is added/removed.

https://bugzilla.gnome.org/show_bug.cgi?id=578933
This commit is contained in:
Tim-Philipp Müller 2016-05-14 10:55:53 +01:00
parent edb27a8ec2
commit 81dec8cc4d
3 changed files with 179 additions and 1 deletions

View file

@ -225,6 +225,10 @@ static void bin_do_eos (GstBin * bin);
static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
static void gst_bin_deep_element_added_func (GstBin * bin, GstBin * sub_bin,
GstElement * element);
static void gst_bin_deep_element_removed_func (GstBin * bin, GstBin * sub_bin,
GstElement * element);
static void gst_bin_update_context (GstBin * bin, GstContext * context);
static void gst_bin_update_context_unlocked (GstBin * bin,
GstContext * context);
@ -260,6 +264,8 @@ enum
ELEMENT_ADDED,
ELEMENT_REMOVED,
DO_LATENCY,
DEEP_ELEMENT_ADDED,
DEEP_ELEMENT_REMOVED,
LAST_SIGNAL
};
@ -400,6 +406,36 @@ gst_bin_class_init (GstBinClass * klass)
g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
/**
* GstBin::deep-element-added:
* @bin: the #GstBin
* @sub_bin: the #GstBin the element was added to
* @element: the #GstElement that was added to @sub_bin
*
* Will be emitted after the element was added to sub_bin.
*
* Since: 1.10
*/
gst_bin_signals[DEEP_ELEMENT_ADDED] =
g_signal_new ("deep-element-added", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, deep_element_added),
NULL, NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 2, GST_TYPE_BIN,
GST_TYPE_ELEMENT);
/**
* GstBin::deep-element-removed:
* @bin: the #GstBin
* @sub_bin: the #GstBin the element was removed from
* @element: the #GstElement that was removed from @sub_bin
*
* Will be emitted after the element was removed from sub_bin.
*
* Since: 1.10
*/
gst_bin_signals[DEEP_ELEMENT_REMOVED] =
g_signal_new ("deep-element-removed", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, deep_element_removed),
NULL, NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 2, GST_TYPE_BIN,
GST_TYPE_ELEMENT);
/**
* GstBin::do-latency:
* @bin: the #GstBin
@ -467,6 +503,9 @@ gst_bin_class_init (GstBinClass * klass)
klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
klass->deep_element_added = gst_bin_deep_element_added_func;
klass->deep_element_removed = gst_bin_deep_element_removed_func;
klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
}
@ -1288,6 +1327,8 @@ no_state_recalc:
gst_child_proxy_child_added ((GstChildProxy *) bin, (GObject *) element,
elem_name);
g_signal_emit (bin, gst_bin_signals[DEEP_ELEMENT_ADDED], 0, bin, element);
g_free (elem_name);
return TRUE;
@ -1317,6 +1358,52 @@ had_parent:
}
}
/* signal vfunc, will be called when a new element was added */
static void
gst_bin_deep_element_added_func (GstBin * bin, GstBin * sub_bin,
GstElement * child)
{
GstBin *parent_bin;
parent_bin = (GstBin *) gst_object_get_parent (GST_OBJECT_CAST (bin));
if (parent_bin == NULL) {
GST_LOG_OBJECT (bin, "no parent, reached top-level");
return;
}
GST_LOG_OBJECT (parent_bin, "emitting deep-element-added for element "
"%" GST_PTR_FORMAT " which has just been added to %" GST_PTR_FORMAT,
sub_bin, child);
g_signal_emit (parent_bin, gst_bin_signals[DEEP_ELEMENT_ADDED], 0, sub_bin,
child);
gst_object_unref (parent_bin);
}
/* signal vfunc, will be called when an element was removed */
static void
gst_bin_deep_element_removed_func (GstBin * bin, GstBin * sub_bin,
GstElement * child)
{
GstBin *parent_bin;
parent_bin = (GstBin *) gst_object_get_parent (GST_OBJECT_CAST (bin));
if (parent_bin == NULL) {
GST_LOG_OBJECT (bin, "no parent, reached top-level");
return;
}
GST_LOG_OBJECT (parent_bin, "emitting deep-element-removed for element "
"%" GST_PTR_FORMAT " which has just been removed from %" GST_PTR_FORMAT,
sub_bin, child);
g_signal_emit (parent_bin, gst_bin_signals[DEEP_ELEMENT_REMOVED], 0, sub_bin,
child);
gst_object_unref (parent_bin);
}
/**
* gst_bin_add:
* @bin: a #GstBin
@ -1623,6 +1710,8 @@ no_state_recalc:
gst_child_proxy_child_removed ((GstChildProxy *) bin, (GObject *) element,
elem_name);
g_signal_emit (bin, gst_bin_signals[DEEP_ELEMENT_REMOVED], 0, bin, element);
g_free (elem_name);
/* element is really out of our control now */
gst_object_unref (element);

View file

@ -147,6 +147,12 @@ struct _GstBin {
* The @handle_message method can be overridden to implement custom
* message handling. @handle_message takes ownership of the message, just like
* #gst_element_post_message.
*
* The @element_added_deep vfunc will be called when a new element has been
* added to any bin inside this bin, so it will also be called if a new child
* was added to a sub-bin of this bin. #GstBin implementations that override
* this message should chain up to the parent class implementation so the
* element-added-deep signal is emitted on all parents.
*/
struct _GstBinClass {
GstElementClass parent_class;
@ -169,8 +175,13 @@ struct _GstBinClass {
/* signal */
gboolean (*do_latency) (GstBin *bin);
/*< public >*/
/* signal */
void (*deep_element_added) (GstBin *bin, GstBin *sub_bin, GstElement *child);
void (*deep_element_removed) (GstBin *bin, GstBin *sub_bin, GstElement *child);
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
gpointer _gst_reserved[GST_PADDING-2];
};
GType gst_bin_get_type (void);

View file

@ -1545,7 +1545,84 @@ GST_START_TEST (test_duration_unknown_overrides)
GST_END_TEST;
static gboolean
element_in_list (GList ** list, GstElement * element)
{
GList *l = g_list_find (*list, element);
if (l == NULL)
return FALSE;
*list = g_list_delete_link (*list, l);
return TRUE;
}
#define element_was_added(e) element_in_list(&added,e)
#define element_was_removed(e) element_in_list(&removed,e)
static void
add_cb (GstBin * pipeline, GstBin * bin, GstElement * element, GList ** list)
{
fail_unless (GST_OBJECT_PARENT (element) == GST_OBJECT_CAST (bin));
*list = g_list_prepend (*list, element);
}
static void
remove_cb (GstBin * pipeline, GstBin * bin, GstElement * element, GList ** list)
{
fail_unless (GST_OBJECT_PARENT (element) == NULL);
*list = g_list_prepend (*list, element);
}
GST_START_TEST (test_deep_added_removed)
{
GstElement *pipe, *e, *bin0, *bin1;
gulong id_removed, id_added;
GList *removed = NULL;
GList *added = NULL;
pipe = gst_pipeline_new (NULL);
id_added = g_signal_connect (pipe, "deep-element-added",
G_CALLBACK (add_cb), &added);
id_removed = g_signal_connect (pipe, "deep-element-removed",
G_CALLBACK (remove_cb), &removed);
/* simple add/remove */
e = gst_element_factory_make ("identity", NULL);
gst_bin_add (GST_BIN (pipe), e);
fail_unless (element_was_added (e));
gst_bin_remove (GST_BIN (pipe), e);
fail_unless (element_was_removed (e));
/* let's try with a deeper hierarchy */
bin0 = gst_bin_new (NULL);
gst_bin_add (GST_BIN (pipe), bin0);
bin1 = gst_bin_new (NULL);
gst_bin_add (GST_BIN (bin0), bin1);
e = gst_element_factory_make ("identity", NULL);
gst_bin_add (GST_BIN (bin1), e);
fail_unless (element_was_added (bin0));
fail_unless (element_was_added (bin1));
fail_unless (element_was_added (e));
fail_unless (added == NULL);
fail_unless (removed == NULL);
gst_bin_remove (GST_BIN (bin1), e);
fail_unless (element_was_removed (e));
fail_unless (added == NULL);
fail_unless (removed == NULL);
/* disconnect signals, unref will trigger remove callbacks otherwise */
g_signal_handler_disconnect (pipe, id_added);
g_signal_handler_disconnect (pipe, id_removed);
gst_object_unref (pipe);
}
GST_END_TEST;
static Suite *
gst_bin_suite (void)
@ -1576,6 +1653,7 @@ gst_bin_suite (void)
tcase_add_test (tc_chain, test_state_change_skip);
tcase_add_test (tc_chain, test_duration_is_max);
tcase_add_test (tc_chain, test_duration_unknown_overrides);
tcase_add_test (tc_chain, test_deep_added_removed);
/* fails on OSX build bot for some reason, and is a bit silly anyway */
if (0)