[rhythmbox] Emit volume-changed from player backends when sink volume is changed

[Jonathan Matthew <jmatthew src gnome org>]

commit 9a826df0c8658561974f291ec3cc656e6aa81197
Author: Jonathan Matthew <jonathan d14n org>
Date:   Wed Apr 22 11:34:47 2009 +1000

    Emit volume-changed from player backends when sink volume is changed
    
    notify::volume is emitted on a streaming thread, so we need to use
    an idle handler to marshal it to the main thread.
---
 backends/gstreamer/rb-player-gst-xfade.c |   22 ++++++++++++++++++++++
 backends/gstreamer/rb-player-gst.c       |   22 ++++++++++++++++++++++
 2 files changed, 44 insertions(+), 0 deletions(-)

diff --git a/backends/gstreamer/rb-player-gst-xfade.c b/backends/gstreamer/rb-player-gst-xfade.c
index 185d626..e0e8806 100644
--- a/backends/gstreamer/rb-player-gst-xfade.c
+++ b/backends/gstreamer/rb-player-gst-xfade.c
@@ -2564,6 +2564,24 @@ tick_timeout (RBPlayerGstXFade *player)
 	return TRUE;
 }
 
+static gboolean
+emit_volume_changed_idle (RBPlayerGstXFade *player)
+{
+	_rb_player_emit_volume_changed (RB_PLAYER (player), player->priv->cur_volume);
+	return FALSE;
+}
+
+static void
+stream_volume_changed (GObject *element, GParamSpec *pspec, RBPlayerGstXFade *player)
+{
+	double v;
+
+	g_object_get (element, "volume", &v, NULL);
+	player->priv->cur_volume = v;
+
+	g_idle_add ((GSourceFunc) emit_volume_changed_idle, player);
+}
+
 /*
  * output sink + adder pipeline:
  *
@@ -2728,6 +2746,10 @@ start_sink_locked (RBPlayerGstXFade *player, GList **messages, GError **error)
 	}
 
 	g_object_set (player->priv->volume_handler, "volume", player->priv->cur_volume, NULL);
+	g_signal_connect_object (player->priv->volume_handler,
+				 "notify::volume",
+				 G_CALLBACK (stream_volume_changed),
+				 player, 0);
 
 
 	sr = gst_element_set_state (player->priv->silencebin, GST_STATE_PLAYING);
diff --git a/backends/gstreamer/rb-player-gst.c b/backends/gstreamer/rb-player-gst.c
index b19ce1e..29823d9 100644
--- a/backends/gstreamer/rb-player-gst.c
+++ b/backends/gstreamer/rb-player-gst.c
@@ -1009,6 +1009,23 @@ rb_player_gst_playing (RBPlayer *player)
 	return mp->priv->playing;
 }
 
+static gboolean
+emit_volume_changed_idle (RBPlayerGst *mp)
+{
+	_rb_player_emit_volume_changed (RB_PLAYER (mp), mp->priv->cur_volume);
+	return FALSE;
+}
+
+static void
+stream_volume_changed (GObject *element, GParamSpec *pspec, RBPlayerGst *mp)
+{
+	gdouble v;
+	g_object_get (element, "volume", &v, NULL);
+	mp->priv->cur_volume = v;
+
+	g_idle_add ((GSourceFunc) emit_volume_changed_idle, mp);
+}
+
 static void
 find_volume_handler (RBPlayerGst *mp)
 {
@@ -1025,6 +1042,11 @@ find_volume_handler (RBPlayerGst *mp)
 		if (mp->priv->volume_handler == NULL) {
 			mp->priv->volume_handler = g_object_ref (mp->priv->playbin);
 		}
+
+		g_signal_connect_object (mp->priv->volume_handler,
+					 "notify::volume",
+					 G_CALLBACK (stream_volume_changed),
+					 mp, 0);
 	}
 }