From 2371d6ba3b62d4d6dc349ab50fa0d76eadfba044 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Janek=20Warcho=C5=82?= <lemniskata.bernoullego@gmail.com>
Date: Sun, 29 Jun 2014 18:25:04 +0200
Subject: [PATCH] Issue 4005: Set X-parent of TextScript to NoteColumn instead
 of PaperColumn

This makes TextScripts consistent with DynamicTexts and LyricTexts.
This is a follow-up to commit 59a842eba0f7ad78289a58a (Issue 2245).

Setting TextScript.cross-staff property to #f is required to ensure
that there are no collisions between TextScripts and cross-staff notes:

\context PianoStaff <<
  \new Staff = "up" {
    b8[
    \change Staff="down"
    d'] ^"text"
  }
  \new Staff = "down" {
    \clef bass
    s4
  }
>>

(see also beam-cross-staff-auto-knee.ly)

As far as I can see, we don't want TextScript.cross-staff to be true
in any situation, because it would result in unwanted collisions.

Why it worked before: cross-staff property in this example evaluated to #f,
but only because of a bug in Script_interface::calc_cross_staff.  That
function should have marked the TextScript as cross-staff if the stem
of the note to which TextScript was attached was cross-staff, but it
didn't work correctly because it expected the parent of the TextScript
to be a NoteColumn, while it actually was a PaperColumn.  When I changed
the parent to be a NoteColumn, the function started working correctly
and marked the TextScript as cross-staff, so I had to change the default
value of the property.
---
 lily/text-engraver.cc | 44 ++++++++++++++++++++++++++++++++++---------
 scm/define-grobs.scm  |  3 ++-
 2 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/lily/text-engraver.cc b/lily/text-engraver.cc
index ffd669ef80..373cbf7ac7 100644
--- a/lily/text-engraver.cc
+++ b/lily/text-engraver.cc
@@ -20,6 +20,8 @@
 #include "directional-element-interface.hh"
 #include "engraver.hh"
 #include "item.hh"
+#include "note-column.hh"
+#include "pointer-group-interface.hh"
 #include "side-position-interface.hh"
 #include "stream-event.hh"
 #include "text-interface.hh"
@@ -29,15 +31,18 @@
 /**
    typeset directions that are  plain text.
 */
+
 class Text_engraver : public Engraver
 {
   vector<Stream_event *> evs_;
+  vector<Grob *> scripts_;
 public:
   TRANSLATOR_DECLARATIONS (Text_engraver);
 protected:
   void stop_translation_timestep ();
   void process_music ();
 
+  DECLARE_ACKNOWLEDGER (note_column);
   DECLARE_TRANSLATOR_LISTENER (text_script);
 };
 
@@ -53,26 +58,44 @@ Text_engraver::process_music ()
 {
   for (vsize i = 0; i < evs_.size (); i++)
     {
-      Stream_event *r = evs_[i];
+      Stream_event *ev = evs_[i];
 
-      // URG: Text vs TextScript
-      Item *text = make_item ("TextScript", r->self_scm ());
+      Item *script = make_item ("TextScript", ev->self_scm ());
+      scripts_.push_back (script);
 
-      int priority = robust_scm2int (text->get_property ("script-priority"),
+      int priority = robust_scm2int (script->get_property ("script-priority"),
                                      200);
 
       /* see script-engraver.cc */
       priority += i;
 
-      text->set_property ("script-priority", scm_from_int (priority));
+      script->set_property ("script-priority", scm_from_int (priority));
 
-      Direction dir = to_dir (r->get_property ("direction"));
+      Direction dir = to_dir (ev->get_property ("direction"));
       if (dir)
-        set_grob_direction (text, dir);
+        set_grob_direction (script, dir);
+
+      SCM mark = ev->get_property ("text");
+
+      script->set_property ("text", mark);
+    }
+}
 
-      SCM mark = r->get_property ("text");
+void
+Text_engraver::acknowledge_note_column (Grob_info info)
+{
+  // Make note column (or rest, if there are no heads) the parent of the script.
+  extract_grob_set (info.grob (), "note-heads", heads);
+  Grob *x_parent = (heads.size ()
+                    ? info.grob ()
+                    : unsmob_grob (info.grob ()->get_object ("rest")));
 
-      text->set_property ("text", mark);
+  for (vsize i = 0; i < scripts_.size (); i++)
+    {
+      Grob *el = scripts_[i];
+
+      if (el && !el->get_parent (X_AXIS) && x_parent)
+        el->set_parent (x_parent, X_AXIS);
     }
 }
 
@@ -80,12 +103,15 @@ void
 Text_engraver::stop_translation_timestep ()
 {
   evs_.clear ();
+  scripts_.clear ();
 }
 
 Text_engraver::Text_engraver ()
 {
 }
 
+ADD_ACKNOWLEDGER (Text_engraver, note_column);
+
 ADD_TRANSLATOR (Text_engraver,
                 /* doc */
                 "Create text scripts.",
diff --git a/scm/define-grobs.scm b/scm/define-grobs.scm
index bed05c7994..ea606ece06 100644
--- a/scm/define-grobs.scm
+++ b/scm/define-grobs.scm
@@ -2353,7 +2353,7 @@
     (TextScript
      . (
         (avoid-slur . around)
-        (cross-staff . ,script-or-side-position-cross-staff)
+        (cross-staff . #f)
         (direction . ,DOWN)
         (extra-spacing-width . (+inf.0 . -inf.0))
         (outside-staff-horizontal-padding . 0.2)
@@ -2371,6 +2371,7 @@
         (stencil . ,ly:text-interface::print)
         (vertical-skylines . ,grob::always-vertical-skylines-from-stencil)
         (Y-extent . ,grob::always-Y-extent-from-stencil)
+        (X-align-on-main-noteheads . #t)
         (X-offset . ,ly:self-alignment-interface::aligned-on-x-parent)
         (Y-offset . ,side-position-interface::y-aligned-side)
         (meta . ((class . Item)
-- 
2.39.5