explanatory comment

diff --git a/gtk2_ardour/editor_selection.cc b/gtk2_ardour/editor_selection.cc
index e1027e4e9bd0418018e59340b16d2277d6aab233..3ad49e9edc8a3d1e318be86fc86669d4c4705aa6 100644 (file)
--- a/gtk2_ardour/editor_selection.cc
+++ b/gtk2_ardour/editor_selection.cc
@@ -991,6 +991,15 @@ Editor::time_selection_changed ()
                return;
        }
 
+       /* XXX this is superficially inefficient. Hide the selection in all
+        * tracks, then show it in all selected tracks.
+        *
+        * However, if you investigate what this actually does, it isn't
+        * anywhere nearly as bad as it may appear. Remember: nothing is
+        * redrawn or even recomputed during these two loops - that only
+        * happens when we next render ...
+        */
+
        for (TrackViewList::iterator i = track_views.begin(); i != track_views.end(); ++i) {
                (*i)->hide_selection ();
        }