[pitivi] widgets: Never change displayed value for keyframed properties

[Thibault Saunier <tsaunier src gnome org>]

commit c0e047d8873394ae0902b1826e80cac2c413d815
Author: Thibault Saunier <tsaunier gnome org>
Date:   Fri Feb 12 19:08:13 2016 +0100

    widgets: Never change displayed value for keyframed properties
    
    First it is meaningless, second it can happen in any thread, making gtk very unhappy
    
    Differential Revision: https://phabricator.freedesktop.org/D764

 pitivi/utils/widgets.py |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/pitivi/utils/widgets.py b/pitivi/utils/widgets.py
index eea5063..23e8b15 100644
--- a/pitivi/utils/widgets.py
+++ b/pitivi/utils/widgets.py
@@ -745,8 +745,14 @@ class GstElementSettingsWidget(Gtk.Box, Loggable):
         self.show_all()
 
     def _propertyChangedCb(self, effect, gst_element, pspec):
+        if gst_element.get_control_binding(pspec.name):
+            self.log("%s controlled, not displaying value", pspec.name)
+            return
+
         widget = self.properties[pspec]
-        widget.setWidgetValue(self.element.get_child_property(pspec.name)[1])
+        res, value = self.element.get_child_property(pspec.name)
+        assert(res)
+        widget.setWidgetValue(value)
 
     def _createKeyframeToggleButton(self, prop):
         button = Gtk.ToggleButton()