element: API: Add GstElement::post_message() vfunc

2 files changed, 39 insertions, 17 deletions

diff --git a/gst/gstelement.c b/gst/gstelement.c
index c03a5c9fe9..fba84c6981 100644
--- a/gst/gstelement.c
+++ b/gst/gstelement.c
@@ -141,6 +141,9 @@ static GstStateChangeReturn gst_element_get_state_func (GstElement * element,
 static GstStateChangeReturn gst_element_set_state_func (GstElement * element,
     GstState state);
 static void gst_element_set_bus_func (GstElement * element, GstBus * bus);
+static gboolean gst_element_post_message_default (GstElement * element,
+    GstMessage * message);
+
 
 static gboolean gst_element_default_send_event (GstElement * element,
     GstEvent * event);
@@ -261,6 +264,7 @@ gst_element_class_init (GstElementClass * klass)
   klass->query = GST_DEBUG_FUNCPTR (gst_element_default_query);
   klass->send_event = GST_DEBUG_FUNCPTR (gst_element_default_send_event);
   klass->numpadtemplates = 0;
+  klass->post_message = GST_DEBUG_FUNCPTR (gst_element_post_message_default);
 
   klass->elementfactory = NULL;
 }
@@ -1819,22 +1823,8 @@ gst_element_query (GstElement * element, GstQuery * query)
   return result;
 }
 
-/**
- * gst_element_post_message:
- * @element: a #GstElement posting the message
- * @message: (transfer full): a #GstMessage to post
- *
- * Post a message on the element's #GstBus. This function takes ownership of the
- * message; if you want to access the message after this call, you should add an
- * additional reference before calling.
- *
- * Returns: %TRUE if the message was successfully posted. The function returns
- * %FALSE if the element did not have a bus.
- *
- * MT safe.
- */
-gboolean
-gst_element_post_message (GstElement * element, GstMessage * message)
+static gboolean
+gst_element_post_message_default (GstElement * element, GstMessage * message)
 {
   GstBus *bus;
   gboolean result = FALSE;
@@ -1870,6 +1860,34 @@ no_bus:
 }
 
 /**
+ * gst_element_post_message:
+ * @element: a #GstElement posting the message
+ * @message: (transfer full): a #GstMessage to post
+ *
+ * Post a message on the element's #GstBus. This function takes ownership of the
+ * message; if you want to access the message after this call, you should add an
+ * additional reference before calling.
+ *
+ * Returns: %TRUE if the message was successfully posted. The function returns
+ * %FALSE if the element did not have a bus.
+ *
+ * MT safe.
+ */
+gboolean
+gst_element_post_message (GstElement * element, GstMessage * message)
+{
+  GstElementClass *klass;
+
+  g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
+
+  klass = GST_ELEMENT_GET_CLASS (element);
+  if (klass->post_message)
+    return klass->post_message (element, message);
+
+  return FALSE;
+}
+
+/**
  * _gst_element_error_printf:
  * @format: the printf-like format to use, or %NULL
  *
diff --git a/gst/gstelement.h b/gst/gstelement.h
index 5c3286fb40..1c6c6a9024 100644
--- a/gst/gstelement.h
+++ b/gst/gstelement.h
@@ -604,6 +604,8 @@ struct _GstElement
  * @query: perform a #GstQuery on the element
  * @request_new_pad_full: called when a new pad is requested. Since: 0.10.32.
  * @state_changed: called immediately after a new state was set. Since: 0.10.36.
+ * @post_message: called when a message is posted on the element. Chain up to
+ *                the parent class' handler to have it posted on the bus. Since: 0.10.37.
  *
  * GStreamer element class. Override the vmethods to implement the element
  * functionality.
@@ -674,8 +676,10 @@ struct _GstElementClass
   void                  (*state_changed)        (GstElement *element, GstState oldstate,
                                                  GstState newstate, GstState pending);
 
+  gboolean              (*post_message)         (GstElement *element, GstMessage *message);
+
   /*< private >*/
-  gpointer _gst_reserved[GST_PADDING-3];
+  gpointer _gst_reserved[GST_PADDING-4];
 };
 
 /* element class pad templates */