[pitivi/ges: 86/287] ui: Wait for TrackObject to be created before creating the MoveContext

[Jean-FranÃois Fortin Tam <jfft src gnome org>]

commit 9c9f1bf6d714a8b5735d35ded0cf250b1850f68e
Author: Thibault Saunier <thibault saunier collabora com>
Date:   Tue Dec 13 20:42:59 2011 -0300

    ui: Wait for TrackObject to be created before creating the MoveContext
    
    When we get a new clip in the timeline, we used to create the MoveContext
    right away which was causing freezes in sometimes, race conditions. We now
    wait for the TrackObjects to be created and inserted in the various tracks
    to create the MoveContext.

 pitivi/ui/timeline.py |   53 +++++++++++++++++++++++++++++++++++++------------
 1 files changed, 40 insertions(+), 13 deletions(-)
---
diff --git a/pitivi/ui/timeline.py b/pitivi/ui/timeline.py
index e069966..e350c55 100644
--- a/pitivi/ui/timeline.py
+++ b/pitivi/ui/timeline.py
@@ -211,6 +211,7 @@ class Timeline(gtk.Table, Loggable, Zoomable):
         self._project = None
         self._timeline = None
         self._duration = 0
+        self._creating_tckobjs_sigid = {}
 
         #Ids of the tracks notify::duration signals
         self._tcks_sig_ids = {}
@@ -412,13 +413,16 @@ class Timeline(gtk.Table, Loggable, Zoomable):
             self.drag_highlight()
         else:
             if  context.targets not in DND_EFFECT_LIST:
-                if not self._temp_objects:
+                if not self._temp_objects and not self._creating_tckobjs_sigid:
                     self.timeline.enable_update(False)
-                    self._add_temp_source()
+                    self._create_temp_source()
+
+                # Let some time for TrackObject-s to be created
+                if self._temp_objects and not self._creating_tckobjs_sigid:
                     focus = self._temp_objects[0]
                     self._move_context = MoveContext(self.timeline,
                             focus, set(self._temp_objects[1:]))
-                self._move_temp_source(self.hadj.props.value + x, y)
+                    self._move_temp_source(self.hadj.props.value + x, y)
         return True
 
     def _dragLeaveCb(self, unused_layout, context, unused_tstamp):
@@ -528,20 +532,43 @@ class Timeline(gtk.Table, Loggable, Zoomable):
 
         return timeline_objs
 
-    def _add_temp_source(self):
-        uris = self.selection_data.split("\n")
+    def _ensureLayer(self):
+        """
+        Make sure we have a layer in our timeline
+
+        Returns: The number of layer present in self.timeline
+        """
         layers = self.timeline.get_layers()
 
-        if layers:
-            layer = layers[0]
-        else:
-            self.error("No layer in the timeline")
-            return
+        if (len(layers) == 0):
+            layer = ges.TimelineLayer()
+            layer.props.auto_transition = True
+            self.timeline.add_layer(layer)
+            layers = [layer]
+
+        return layers
+
+    def _create_temp_source(self):
+        infos = self._factories
+        layer = self._ensureLayer()[0]
+        duration = 0
 
-        for uri in uris:
-            src = ges.TimelineFileSource(uri)
+        for info in infos:
+            src = ges.TimelineFileSource(info.get_uri())
+            src.props.start = duration
+            duration += info.get_duration()
             layer.add_object(src)
-            self._temp_objects.insert(0, src)
+            id = src.connect("track-object-added", self._trackObjectsCreatedCb, src)
+            self._creating_tckobjs_sigid[src] = id
+
+    def _trackObjectsCreatedCb(self, unused_tl, track_object, tlobj):
+        # Make sure not to start the moving process before the TrackObject-s
+        # are created. We concider that the time between the different
+        # TrackObject-s creation is short enough so we are all good when the
+        # first TrackObject is added to the TimelineObject
+        self._temp_objects.insert(0, tlobj)
+        tlobj.disconnect(self._creating_tckobjs_sigid[tlobj])
+        del self._creating_tckobjs_sigid[tlobj]
 
     def _move_temp_source(self, x, y):
         x1, y1, x2, y2 = self._controls.get_allocation()