[pitivi] timeline: Allow selection and seek on 'right or middle' clicks

[Thibault Saunier <tsaunier src gnome org>]

commit 4c3cbd92f226901cb5b1e189d49cfe3e2baa68a1
Author: Thibault Saunier <tsaunier gnome org>
Date:   Mon Sep 21 10:29:32 2015 +0200

    timeline: Allow selection and seek on 'right or middle' clicks
    
    The behaviour was not really defined and was weird and unexpected.
    
    Fixes T3334

 pitivi/timeline/timeline.py |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/pitivi/timeline/timeline.py b/pitivi/timeline/timeline.py
index e67df1f..9cbd74e 100644
--- a/pitivi/timeline/timeline.py
+++ b/pitivi/timeline/timeline.py
@@ -569,13 +569,14 @@ class Timeline(Gtk.EventBox, Zoomable, Loggable):
         return False
 
     def __buttonReleaseEventCb(self, unused_widget, event):
+        res, button = event.get_button()
         if self.draggingElement:
             self.dragEnd()
         elif self.__moving_layer:
             self.__endMovingLayer()
 
             return False
-        else:
+        elif button == 1:
             self._selectUnderMarquee()
 
         event_widget = self.get_event_widget(event)