[pitivi] Use MoveContext when dragging clips from the sourcelist to the timeline. Fixes #589695.

[Edward Hervey <edwardrv src gnome org>]

commit c80658faf13a8cd97fb240c019f83dd457851f4a
Author: Alessandro Decina <alessandro d gmail com>
Date:   Mon Jul 27 15:47:37 2009 +0200

    Use MoveContext when dragging clips from the sourcelist to the timeline. Fixes #589695.

 pitivi/timeline/timeline.py |   26 ++++++++++++++++++--------
 pitivi/ui/timeline.py       |   14 +++++++++-----
 2 files changed, 27 insertions(+), 13 deletions(-)
---
diff --git a/pitivi/timeline/timeline.py b/pitivi/timeline/timeline.py
index 068e07d..ca153a5 100644
--- a/pitivi/timeline/timeline.py
+++ b/pitivi/timeline/timeline.py
@@ -25,7 +25,7 @@ from bisect import bisect_left
 from pitivi.signalinterface import Signallable
 from pitivi.log.loggable import Loggable
 from pitivi.utils import UNKNOWN_DURATION, closest_item, PropertyChangeTracker
-from pitivi.timeline.track import SourceTrackObject, TrackError
+from pitivi.timeline.track import TrackObject, SourceTrackObject, TrackError
 from pitivi.stream import match_stream_groups_map
 from pitivi.utils import start_insort_right, infinity, getPreviousObject, \
         getNextObject
@@ -1045,15 +1045,21 @@ class MoveContext(EditingContext):
     def __init__(self, timeline, focus, other):
         EditingContext.__init__(self, timeline, focus, other)
 
-        self.timeline_objects = set(track_object.timeline_object
-                for track_object in other)
-        self.timeline_objects.add(focus.timeline_object)
-
         min_priority = infinity
         earliest = infinity
         latest = 0
         self.default_originals = {}
-        for timeline_object in self.timeline_objects:
+        self.timeline_objects = set([])
+        all_objects = set(other)
+        all_objects.add(focus)
+        for obj in all_objects:
+            if isinstance(obj, TrackObject):
+                timeline_object = obj.timeline_object
+            else:
+                timeline_object = obj
+
+            self.timeline_objects.add(timeline_object)
+
             self.default_originals[timeline_object] = \
                     self._getTimelineObjectValues(timeline_object)
 
@@ -1112,8 +1118,12 @@ class MoveContext(EditingContext):
     def finish(self):
         EditingContext.finish(self)
 
-        initial_position = self.default_originals[self.focus.timeline_object][0]
-        initial_priority = self.default_originals[self.focus.timeline_object][-1]
+        if isinstance(self.focus, TrackObject):
+            focus_timeline_object = self.focus.timeline_object
+        else:
+            focus_timeline_object = self.focus
+        initial_position = self.default_originals[focus_timeline_object][0]
+        initial_priority = self.default_originals[focus_timeline_object][-1]
 
         final_priority = self.focus.priority
         final_position = self.focus.start
diff --git a/pitivi/ui/timeline.py b/pitivi/ui/timeline.py
index 0f8a137..b9cbfa1 100644
--- a/pitivi/ui/timeline.py
+++ b/pitivi/ui/timeline.py
@@ -38,6 +38,7 @@ from timelinecontrols import TimelineControls
 from pitivi.receiver import receiver, handler
 from zoominterface import Zoomable
 from pitivi.ui.common import LAYER_HEIGHT_EXPANDED, LAYER_SPACING
+from pitivi.timeline.timeline import MoveContext
 
 # tooltip text for toolbar
 DELETE = _("Delete Selected")
@@ -288,6 +289,9 @@ class Timeline(gtk.Table, Loggable, Zoomable):
             if not self._temp_objects:
                 self.timeline.disableUpdates()
                 self._add_temp_source()
+                focus = self._temp_objects[0]
+                self._move_context = MoveContext(self.timeline,
+                        focus, set(self._temp_objects[1:]))
             self._move_temp_source(x, y)
         return True
 
@@ -304,7 +308,11 @@ class Timeline(gtk.Table, Loggable, Zoomable):
     def _dragDropCb(self, widget, context, x, y, timestamp):
         self.app.action_log.begin("add clip")
         self._add_temp_source()
+        focus = self._temp_objects[0]
+        self._move_context = MoveContext(self.timeline,
+                focus, set(self._temp_objects[1:]))
         self._move_temp_source(x, y)
+        self._move_context.finish()
         self.app.action_log.commit()
         context.drop_finish(True, timestamp)
         self._factories = None
@@ -340,11 +348,7 @@ class Timeline(gtk.Table, Loggable, Zoomable):
         x, y = self._canvas.convert_from_pixels(x - offset, y)
         priority = int((y // (LAYER_HEIGHT_EXPANDED + LAYER_SPACING)))
         delta = Zoomable.pixelToNs(x)
-        for obj in self._temp_objects:
-            obj.setStart(max(0, delta), snap=True)
-            obj.priority = priority
-            delta += obj.duration
-
+        self._move_context.editTo(delta, priority)
 
 ## Zooming and Scrolling