Outliner: Avoid rebuilding tree on selection/active changes

We can avoid the rather expensive outliner tree rebuilds and only redraw
if nothing but the selection or active item changes. This should give a
bit of speedup for heavy scenes.

For this to work I had to correct a few notifiers, some were only
sending selection/active change notifiers that actually did things like
adding objects. I also added a more precise notifier type for when the
active collection changes. At the notifier subtype/action level we're
not even close to running out of bits, so this should be fine.
Also had to correct a wrong notifier check (was using `&` rather than
`==`).

1 files changed, 1 insertions, 0 deletions

diff --git a/source/blender/editors/space_outliner/outliner_tools.c b/source/blender/editors/space_outliner/outliner_tools.c
index 4b037327038..2a13f9d6a66 100644
--- a/source/blender/editors/space_outliner/outliner_tools.c
+++ b/source/blender/editors/space_outliner/outliner_tools.c
@@ -1630,6 +1630,7 @@ static int outliner_delete_exec(bContext *C, wmOperator *op)
 
   DEG_id_tag_update(&scene->id, ID_RECALC_SELECT);
   WM_event_add_notifier(C, NC_SCENE | ND_OB_SELECT, scene);
+  WM_event_add_notifier(C, NC_SCENE | ND_LAYER_CONTENT, scene);
   ED_outliner_select_sync_from_object_tag(C);
 
   return OPERATOR_FINISHED;