Re: Colored box behind a single note

[Werner LEMBERG]

[Moving the discussion to lilypond-devel.]

>> A loop?

Attached a new version of the patch, now using a loop.


    Werner

diff --git a/lily/horizontal-bracket-engraver.cc 
b/lily/horizontal-bracket-engraver.cc
index 608af35965..a42268a357 100644
--- a/lily/horizontal-bracket-engraver.cc
+++ b/lily/horizontal-bracket-engraver.cc
@@ -56,10 +56,23 @@ Horizontal_bracket_engraver::listen_note_grouping 
(Stream_event *ev)
 {
   Direction d = to_dir (ev->get_property ("span-direction"));
 
+  // Allow one single-moment bracket.  Abbreviating a horizontal bracket's
+  // `START' span-direction with `L' and `STOP' with `R', this means that we
+  // can have
+  //
+  //   LLL...LLR
+  //
+  // or
+  //
+  //   LRRR...RR
+  //
+  // events attached to a single moment (we don't take care of the order of
+  // `L' and `R' events).
+
   if (d == STOP)
     {
       pop_count_++;
-      if (pop_count_ > bracket_stack_.size ())
+      if (pop_count_ > bracket_stack_.size () + 1)
         ev->origin ()->warning (_ ("do not have that many brackets"));
     }
   else
@@ -68,22 +81,33 @@ Horizontal_bracket_engraver::listen_note_grouping 
(Stream_event *ev)
       events_.push_back (ev);
     }
 
-  if (pop_count_ && push_count_)
+  if (pop_count_ >= 2 && push_count_ >= 2)
     ev->origin ()->warning (_ ("conflicting note group events"));
 }
 
 void
 Horizontal_bracket_engraver::acknowledge_note_column (Grob_info gi)
 {
+  bool process_single_moment_bracket = pop_count_ && push_count_;
+
   for (vsize i = 0; i < bracket_stack_.size (); i++)
     {
-      Side_position_interface::add_support (bracket_stack_[i], gi.grob ());
-      Pointer_group_interface::add_grob (bracket_stack_[i],
-                                         ly_symbol2scm ("columns"), gi.grob 
());
-      add_bound_item (bracket_stack_[i],
-                      gi.grob ());
-      add_bound_item (text_stack_[i],
-                      gi.grob ());
+      // For a single-moment horizontal bracket (which is the most recently
+      // pushed element on the stack), use the current note column for both
+      // the left and right bound of the bracket.
+      int count = (process_single_moment_bracket
+                   && i + 1 == bracket_stack_.size ()) ? 2 : 1;
+
+      for (int j = 0; j < count; j++)
+        {
+          Side_position_interface::add_support (bracket_stack_[i],
+                                                gi.grob ());
+          Pointer_group_interface::add_grob (bracket_stack_[i],
+                                             ly_symbol2scm ("columns"),
+                                             gi.grob ());
+          add_bound_item (bracket_stack_[i], gi.grob ());
+          add_bound_item (text_stack_[i], gi.grob ());
+        }
     }
 }