[pitivi] sourcelist: always display video before audio. Fixes #575957.

[Edward Hervey <edwardrv src gnome org>]

commit b885cc881f7e7623858a70d316a12f690f8d1e22
Author: Alessandro Decina <alessandro decina collabora co uk>
Date:   Wed Mar 25 16:07:35 2009 +0100

    sourcelist: always display video before audio. Fixes #575957.
---
 pitivi/ui/sourcelist.py |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/pitivi/ui/sourcelist.py b/pitivi/ui/sourcelist.py
index 8561338..2cb01f6 100644
--- a/pitivi/ui/sourcelist.py
+++ b/pitivi/ui/sourcelist.py
@@ -108,9 +108,14 @@ def beautify_stream(stream):
     raise NotImplementedError
 
 def beautify_factory(factory):
+    ranks = {VideoStream: 0, AudioStream: 1}
+    def stream_sort_key(stream):
+        return ranks[type(stream)]
+
+    streams = factory.getOutputStreams()
+    streams.sort(key=stream_sort_key)
     return ("<b>" + unquote(factory.displayname) + "</b>\n" +
-        "\n".join((beautify_stream(stream)
-            for stream in factory.getOutputStreams())))
+        "\n".join((beautify_stream(stream) for stream in streams)))
 
 class SourceList(gtk.VBox, Loggable):
     """ Widget for listing sources """