ges: track-element: Try to create NleObject as soon as possible

This way we have informations about the content of the
children as soon as possible.

Most code paths where already ready to handle that as we use it for
copying clips.

Fix framepositionner to properly handle that (it would have broke
with copied clips before).

Reviewed-by: Thibault Saunier <thibault.saunier@collabora.com>
Differential Revision: https://phabricator.freedesktop.org/D736

2 files changed, 19 insertions, 23 deletions

diff --git a/ges/ges-track-element.c b/ges/ges-track-element.c
index 16f5f078..2ba1089d 100644
--- a/ges/ges-track-element.c
+++ b/ges/ges-track-element.c
@@ -105,6 +105,7 @@ GESTrackType _get_track_types (GESTimelineElement * object);
 
 static GParamSpec **default_list_children_properties (GESTrackElement * object,
     guint * n_properties);
+static gboolean ensure_nle_object (GESTrackElement * object);
 
 static void
 _update_control_bindings (GESTimelineElement * element, GstClockTime inpoint,
@@ -208,9 +209,11 @@ ges_track_element_dispose (GObject * object)
 }
 
 static void
-ges_track_element_finalize (GObject * object)
+ges_track_element_constructed (GObject * object)
 {
-  G_OBJECT_CLASS (ges_track_element_parent_class)->finalize (object);
+  ensure_nle_object (GES_TRACK_ELEMENT (object));
+
+  G_OBJECT_CLASS (ges_track_element_parent_class)->constructed (object);
 }
 
 static void
@@ -224,7 +227,7 @@ ges_track_element_class_init (GESTrackElementClass * klass)
   object_class->get_property = ges_track_element_get_property;
   object_class->set_property = ges_track_element_set_property;
   object_class->dispose = ges_track_element_dispose;
-  object_class->finalize = ges_track_element_finalize;
+  object_class->constructed = ges_track_element_constructed;
 
 
   /**
diff --git a/ges/gstframepositionner.c b/ges/gstframepositionner.c
index b4aaef2a..8c42f90b 100644
--- a/ges/gstframepositionner.c
+++ b/ges/gstframepositionner.c
@@ -165,8 +165,7 @@ _track_restriction_changed_cb (GESTrack * track, GParamSpec * arg G_GNUC_UNUSED,
 }
 
 static void
-_track_changed_cb (GESTrackElement * trksrc, GParamSpec * arg G_GNUC_UNUSED,
-    GstFramePositionner * pos)
+set_track (GstFramePositionner * pos)
 {
   GESTrack *new_track;
 
@@ -177,17 +176,26 @@ _track_changed_cb (GESTrackElement * trksrc, GParamSpec * arg G_GNUC_UNUSED,
         (GWeakNotify) _weak_notify_cb, pos);
   }
 
-  new_track = ges_track_element_get_track (trksrc);
+  new_track = ges_track_element_get_track (pos->track_source);
   if (new_track) {
     pos->current_track = new_track;
     g_object_weak_ref (G_OBJECT (new_track), (GWeakNotify) _weak_notify_cb,
         pos);
     GST_DEBUG_OBJECT (pos, "connecting to track : %p", pos->current_track);
+
     g_signal_connect (pos->current_track, "notify::restriction-caps",
         (GCallback) _track_restriction_changed_cb, pos);
     sync_properties_with_track (pos, pos->current_track);
-  } else
+  } else {
     pos->current_track = NULL;
+  }
+}
+
+static void
+_track_changed_cb (GESTrackElement * trksrc, GParamSpec * arg G_GNUC_UNUSED,
+    GstFramePositionner * pos)
+{
+  set_track (pos);
 }
 
 void
@@ -198,24 +206,9 @@ ges_frame_positionner_set_source_and_filter (GstFramePositionner * pos,
   pos->capsfilter = capsfilter;
   pos->current_track = ges_track_element_get_track (trksrc);
 
-  if (!pos->current_track) {
-    GST_INFO_OBJECT (pos, "No track set, won't be usable");
-
-    return;
-  }
-
-  g_object_add_weak_pointer (G_OBJECT (pos->track_source),
-      ((gpointer *) & pos->track_source));
-  g_object_weak_ref (G_OBJECT (pos->current_track),
-      (GWeakNotify) _weak_notify_cb, pos);
-
-  GST_DEBUG_OBJECT (pos, "connecting to track : %p", pos->current_track);
-
-  g_signal_connect (pos->current_track, "notify::restriction-caps",
-      (GCallback) _track_restriction_changed_cb, pos);
   g_signal_connect (trksrc, "notify::track", (GCallback) _track_changed_cb,
       pos);
-  sync_properties_with_track (pos, pos->current_track);
+  set_track (pos);
 }
 
 static void