[rhythmbox] xfade: deal with tag messages posted by the sink

[Jonathan Matthew <jmatthew src gnome org>]

commit b1cb740e1d1811857a386ce1921d197166e19950
Author: Jonathan Matthew <jonathan d14n org>
Date:   Thu Dec 13 23:23:53 2012 +1000

    xfade: deal with tag messages posted by the sink
    
    With GStreamer 1.0 tag messages are posted by the sink rather than
    the element that found the tags, so we can't find the stream that
    the tags apply to by checking the message source any more.  For now,
    we associate tag messages with the first available stream that is
    playing, but at some point we should be able to get a stream id
    for the tags.

 backends/gstreamer/rb-player-gst-xfade.c |   36 ++++++++++++++++++++++-------
 1 files changed, 27 insertions(+), 9 deletions(-)
---
diff --git a/backends/gstreamer/rb-player-gst-xfade.c b/backends/gstreamer/rb-player-gst-xfade.c
index 9544561..cdb0e24 100644
--- a/backends/gstreamer/rb-player-gst-xfade.c
+++ b/backends/gstreamer/rb-player-gst-xfade.c
@@ -578,6 +578,31 @@ find_stream_by_state (RBPlayerGstXFade *player, gint state_mask)
 	return NULL;
 }
 
+static RBXFadeStream *
+find_stream_for_message (RBPlayerGstXFade *player, GstMessage *message)
+{
+	GstObject *message_src;
+	RBXFadeStream *stream;
+
+	/* first see if the message comes from an element in the stream bin */
+	message_src = GST_MESSAGE_SRC (message);
+	if (GST_IS_PAD (message_src)) {
+		message_src = GST_OBJECT_PARENT (message_src);
+	}
+	stream = find_stream_by_element (player, GST_ELEMENT (message_src));
+	if (stream != NULL)
+		return stream;
+
+	/* tag messages are emitted by the sink, so we can't find the message
+	 * source in a stream bin.  attribute them to the first playing stream.
+	 */
+	if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_TAG) {
+		return find_stream_by_state (player, FADING_IN | PLAYING | FADING_OUT_PAUSED | PAUSED | PENDING_REMOVE | REUSING);
+	}
+
+	return NULL;
+}
+
 static void
 rb_player_gst_xfade_get_property (GObject *object,
 				  guint prop_id,
@@ -1631,17 +1656,12 @@ static gboolean
 rb_player_gst_xfade_bus_cb (GstBus *bus, GstMessage *message, RBPlayerGstXFade *player)
 {
 	RBXFadeStream *stream;
-	GstObject *message_src;
 
 	g_return_val_if_fail (player != NULL, FALSE);
 
 	g_rec_mutex_lock (&player->priv->stream_list_lock);
 
-	message_src = GST_MESSAGE_SRC (message);
-	if (GST_IS_PAD (message_src)) {
-		message_src = GST_OBJECT_PARENT (message_src);
-	}
-	stream = find_stream_by_element (player, GST_ELEMENT (message_src));
+	stream = find_stream_for_message (player, message);
 	g_rec_mutex_unlock (&player->priv->stream_list_lock);
 
 	switch (GST_MESSAGE_TYPE (message)) {
@@ -2777,14 +2797,12 @@ start_sink_locked (RBPlayerGstXFade *player, GList **messages, GError **error)
 			{
 				char *debug;
 				GError *gst_error = NULL;
-				GstObject *message_src;
 				RBXFadeStream *stream;
 
 				/* we only want to process errors from the sink here.
 				 * errors from streams should go to the normal message handler.
 				 */
-				message_src = GST_MESSAGE_SRC (message);
-				stream = find_stream_by_element (player, GST_ELEMENT (message_src));
+				stream = find_stream_for_message (player, message);
 				if (stream != NULL) {
 					rb_debug ("got an error from a stream; passing it to the bus handler");
 					*messages = g_list_append (*messages, gst_message_ref (message));