[pitivi] Add edge snapping when trimming at start.

[Edward Hervey <edwardrv src gnome org>]

commit 01e8dbc5350be83c30fac16f51b7231a9693d9d0
Author: Alessandro Decina <alessandro d gmail com>
Date:   Tue Apr 28 17:34:35 2009 +0200

    Add edge snapping when trimming at start.
    
    Fixes #580172.
---
 pitivi/timeline/timeline.py |    3 +++
 pitivi/ui/trackobject.py    |    2 +-
 2 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/pitivi/timeline/timeline.py b/pitivi/timeline/timeline.py
index 2ee4fbd..4715f61 100644
--- a/pitivi/timeline/timeline.py
+++ b/pitivi/timeline/timeline.py
@@ -202,6 +202,9 @@ class TimelineObject(object, Signallable, Loggable):
         if not self.track_objects:
             raise TimelineError()
 
+        if snap:
+            time = self.timeline.snapToEdge(time)
+
         for track_object in self.track_objects:
             track_object.trimObjectStart(time)
 
diff --git a/pitivi/ui/trackobject.py b/pitivi/ui/trackobject.py
index 1fbdd3e..743b58c 100644
--- a/pitivi/ui/trackobject.py
+++ b/pitivi/ui/trackobject.py
@@ -82,7 +82,7 @@ class StartHandle(TrimHandle):
 
         def set_pos(self, obj, pos):
             new_start = max(self._view.pixelToNs(pos[0]), 0)
-            self._view.element.trimStart(new_start)
+            self._view.element.trimStart(new_start, snap=True)
 
 class EndHandle(TrimHandle):