Outliner: Refactor how lazy-building of children is done

Makes the lazy-building (where children are only built when the parent
isn't collapsed) more generic, so more display modes can use it. So far
this was hardcoded for the "Data API" display mode.

This will be used to work around a big performance issue with the
Library Overrides Hierachies view in a complex production file, see
following commit.

1 files changed, 2 insertions, 2 deletions

diff --git a/source/blender/editors/space_outliner/outliner_select.cc b/source/blender/editors/space_outliner/outliner_select.cc
index 877e0fc325c..080274997db 100644
--- a/source/blender/editors/space_outliner/outliner_select.cc
+++ b/source/blender/editors/space_outliner/outliner_select.cc
@@ -1886,7 +1886,7 @@ static TreeElement *outliner_walk_left(SpaceOutliner *space_outliner,
   TreeStoreElem *tselem = TREESTORE(te);
 
   if (TSELEM_OPEN(tselem, space_outliner)) {
-    outliner_item_openclose(space_outliner, te, false, toggle_all);
+    outliner_item_openclose(te, false, toggle_all);
   }
   /* Only walk up a level if the element is closed and not toggling expand */
   else if (!toggle_all && te->parent) {
@@ -1907,7 +1907,7 @@ static TreeElement *outliner_walk_right(SpaceOutliner *space_outliner,
     te = reinterpret_cast<TreeElement *>(te->subtree.first);
   }
   else {
-    outliner_item_openclose(space_outliner, te, true, toggle_all);
+    outliner_item_openclose(te, true, toggle_all);
   }
 
   return te;