]> git.donarmstrong.com Git - lilypond.git/blobdiff - lily/accidental-engraver.cc
Merge commit 'origin/dev/jneeman' into systems-per-page
[lilypond.git] / lily / accidental-engraver.cc
index 808c2408ec5a76947e8de6ff12d16366516ca942..24340ed70f2057e7fae2964d77723c7df260b192 100644 (file)
@@ -1,32 +1,42 @@
 /*
-  accidental-engraver.cc -- implement accidental_engraver
+  accidental-engraver.cc -- implement Accidental_engraver
 
-  (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+  source file of the GNU LilyPond music typesetter
+
+  (c) 1997--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   Modified 2001--2002 by Rune Zedeler <rz@daimi.au.dk>
 */
 
-#include "event.hh"
-#include "spanner.hh"
-#include "item.hh"
-#include "tie.hh"
-#include "rhythmic-head.hh"
-#include "engraver-group-engraver.hh"
 #include "accidental-placement.hh"
-#include "side-position-interface.hh"
-#include "engraver.hh"
 #include "arpeggio.hh"
-#include "warn.hh"
 #include "context.hh"
+#include "duration.hh"
+#include "engraver.hh"
+#include "international.hh"
+#include "item.hh"
+#include "pitch.hh"
 #include "protected-scm.hh"
+#include "rhythmic-head.hh"
+#include "separation-item.hh"
+#include "side-position-interface.hh"
+#include "spanner.hh"
+#include "stream-event.hh"
+#include "tie.hh"
+#include "warn.hh"
 
+#include "translator.icc"
 
-struct Accidental_entry {
+class Accidental_entry
+{
+public:
   bool done_;
-  Music * melodic_;
-  Grob * accidental_;
+  Stream_event *melodic_;
+  Grob *accidental_;
   Context *origin_;
-  Grob*  head_;
+  Engraver *origin_engraver_;
+  Grob *head_;
   bool tied_;
+
   Accidental_entry ();
 };
 
@@ -34,51 +44,53 @@ Accidental_entry::Accidental_entry ()
 {
   tied_ = false;
   done_ = false;
-  melodic_ =0;
+  melodic_ = 0;
   accidental_ = 0;
   origin_ = 0;
   head_ = 0;
 }
 
-struct Accidental_engraver : Engraver {
+class Accidental_engraver : public Engraver
+{
+  void update_local_key_signature (SCM new_signature);
+  void create_accidental (Accidental_entry *entry, bool, bool);
+  Grob *make_standard_accidental (Stream_event *note, Grob *note_head, Engraver *trans, bool);
+  Grob *make_suggested_accidental (Stream_event *note, Grob *note_head, Engraver *trans);
+
 protected:
   TRANSLATOR_DECLARATIONS (Accidental_engraver);
-  virtual void process_music ();
-  virtual void acknowledge_grob (Grob_info);
-  virtual void stop_translation_timestep ();
-  virtual void initialize ();
-  virtual void process_acknowledged_grobs ();
-  virtual void finalize ();
-public:
+  void process_music ();
 
-  Protected_scm last_keysig_;
+  void acknowledge_tie (Grob_info);
+  void acknowledge_arpeggio (Grob_info);
+  void acknowledge_rhythmic_head (Grob_info);
+  void acknowledge_finger (Grob_info);
+  void acknowledge_note_column (Grob_info);
 
-  /*
-    Urgh. Since the accidentals depend on lots of variables, we have to
-    store all information before we can really create the accidentals.
-  */
-  Link_array<Grob> left_objects_;
-  Link_array<Grob> right_objects_;
+  void stop_translation_timestep ();
+  void process_acknowledged ();
+  
+  virtual void finalize ();
+  virtual void derived_mark () const;
 
-  Grob * accidental_placement_;
+public:
+  SCM last_keysig_;
+
+  vector<Grob*> left_objects_;
+  vector<Grob*> right_objects_;
 
-  Array<Accidental_entry> accidentals_;
-  Link_array<Spanner> ties_;
+  Grob *accidental_placement_;
 
-  SCM get_bar_num ();
+  vector<Accidental_entry> accidentals_;
+  vector<Spanner*> ties_;
+  vector<Grob*> note_columns_;
 };
 
+/*
+  localKeySignature is changed at runtime, which means that references
+  in grobs should always store ly_deep_copy ()s of those.
+*/
 
-static void
-set_property_on_children (Context * trans, const char * sym, SCM val)
-{
-  trans->set_property (sym, val);
-  for (SCM p = trans->children_contexts (); ly_c_pair_p (p); p = ly_cdr (p))
-    {
-      Context *trg =  unsmob_context (ly_car (p));
-      set_property_on_children (trg, sym, ly_deep_copy (val));
-    }
-}
 
 Accidental_engraver::Accidental_engraver ()
 {
@@ -87,255 +99,373 @@ Accidental_engraver::Accidental_engraver ()
 }
 
 void
-Accidental_engraver::initialize ()
+Accidental_engraver::derived_mark () const
+{
+  scm_gc_mark (last_keysig_);
+}
+
+void
+Accidental_engraver::update_local_key_signature (SCM new_sig)
 {
-  last_keysig_ = get_property ("keySignature");
+  last_keysig_ = new_sig;
+  set_context_property_on_children (context (),
+                                   ly_symbol2scm ("localKeySignature"),
+                                   new_sig);
+
+  Context *trans = context ()->get_parent_context ();
 
-  Context * trans_ = context ();
-  while (trans_)
+  /* Reset parent contexts so that e.g. piano-accidentals won't remember old
+     cross-staff accidentals after key-sig-changes */
+
+  SCM val;
+  while (trans && trans->where_defined (ly_symbol2scm ("localKeySignature"), &val)==trans)
     {
-      trans_ -> set_property ("localKeySignature",
-                             ly_deep_copy (last_keysig_));
-      trans_ = trans_->get_parent_context ();
+      trans->set_property ("localKeySignature", ly_deep_copy (last_keysig_));
+      trans = trans->get_parent_context ();
     }
-  set_property_on_children (context (),"localKeySignature", last_keysig_);
 }
 
-/*
 
-  calculates the number of accidentals on basis of the current local key
-  sig (passed as argument)
+/** Calculate the number of accidentals on basis of the current local key
+    sig (passed as argument)
 
-  Returns number of accidentals (0, 1 or 2).
+    * First check step+octave (taking into account barnumbers if necessary).
 
-*/
-static int
-number_accidentals_from_sig (bool *different,
-                            SCM sig, Pitch *pitch, SCM curbarnum, SCM lazyness, 
-                            bool ignore_octave)
+    * Then check the global signature (only step).
+
+    Return number of accidentals (0, 1 or 2).  */
+
+static bool
+recent_enough (int bar_number, SCM alteration_def, SCM laziness)
+{
+  if (scm_is_number (alteration_def)
+      || laziness == SCM_BOOL_T)
+    return true;
+
+  return (bar_number <= scm_to_int (scm_cadr (alteration_def)) + scm_to_int (laziness));
+}
+
+static Rational
+extract_alteration (SCM alteration_def)
 {
-  int n = pitch->get_notename ();
-  int o = pitch->get_octave ();
-  int a = pitch->get_alteration ();
-  int curbarnum_i = ly_scm2int (curbarnum);
-  int accbarnum_i = 0;
-
-  SCM prev;
-  if (ignore_octave)
-    prev = ly_assoc_cdr (scm_int2num (n), sig);
+  if (scm_is_number (alteration_def))
+    return ly_scm2rational (alteration_def);
+  else if (scm_is_pair (alteration_def))
+    return ly_scm2rational (scm_car (alteration_def));
+  else if (alteration_def == SCM_BOOL_F)
+    return Rational (0);
   else
-    prev = scm_assoc (scm_cons (scm_int2num (o), scm_int2num (n)), sig);
+    assert (0);
+  return Rational (0);
+}
+
+bool
+is_tied (SCM alteration_def)
+{
+  SCM tied = ly_symbol2scm ("tied");
+  return (alteration_def == tied
+         || (scm_is_pair (alteration_def) && scm_car (alteration_def) == tied));
+}
+
+struct Accidental_result
+{
+  bool need_acc;
+  bool need_restore;
+
+  Accidental_result ()
+  {
+    need_restore = need_acc = false;
+  }
+
+  Accidental_result (bool restore, bool acc)
+  {
+    need_restore = restore;
+    need_acc = acc;
+  }
+
+  Accidental_result (SCM scm)
+  {
+    need_restore = to_boolean (scm_car (scm));
+    need_acc = to_boolean (scm_cdr (scm));
+  }
+
+  int score () const
+  {
+    return need_acc ? 1 : 0
+      + need_restore ? 1 : 0;
+  }
+};
+
+Accidental_result
+check_pitch_against_signature (SCM key_signature, Pitch const &pitch,
+                              int bar_number, SCM laziness, bool ignore_octave)
+{
+  Accidental_result result;
+  int n = pitch.get_notename ();
+  int o = pitch.get_octave ();
+
+  SCM previous_alteration = SCM_BOOL_F;
 
-  /* should really be true unless prev == SCM_BOOL_F */
-  if (ly_c_pair_p (prev) && ly_c_pair_p (ly_cdr (prev)))
+  SCM from_same_octave = ly_assoc_get (scm_cons (scm_from_int (o),
+                                                scm_from_int (n)), key_signature, SCM_BOOL_F);
+  SCM from_key_signature = ly_assoc_get (scm_from_int (n), key_signature, SCM_BOOL_F);
+  SCM from_other_octaves = SCM_BOOL_F;
+  for (SCM s = key_signature; scm_is_pair (s); s = scm_cdr (s))
     {
-      accbarnum_i = ly_scm2int (ly_cddr (prev));
-      prev = scm_cons (ly_car (prev), ly_cadr (prev));
+      SCM entry = scm_car (s);
+      if (scm_is_pair (scm_car (entry))
+         && scm_cdar (entry) == scm_from_int (n))
+       {
+         from_other_octaves = scm_cdr (entry);
+         break;
+       }
     }
-  
-  /* If an accidental was not found or the accidental was too old */
-  if (prev == SCM_BOOL_F ||
-      (ly_c_number_p (lazyness) && curbarnum_i > accbarnum_i + ly_scm2int (lazyness)))
-    prev = scm_assoc (scm_int2num (n), sig);
 
+  if (!ignore_octave
+      && from_same_octave != SCM_BOOL_F
+      && recent_enough (bar_number, from_same_octave, laziness))
+    previous_alteration = from_same_octave;
+  else if (ignore_octave
+          && from_other_octaves != SCM_BOOL_F
+          && recent_enough (bar_number, from_other_octaves, laziness))
+    previous_alteration = from_other_octaves;
+  else if (from_key_signature != SCM_BOOL_F)
+    previous_alteration = from_key_signature;
+
+  if (is_tied (previous_alteration))
+    {
+      result.need_acc = true;
+    }
+  else
+    {
+      Rational prev = extract_alteration (previous_alteration);
+      Rational alter = pitch.get_alteration ();
+
+      if (alter != prev)
+        {
+         result.need_acc = true;
+         if (alter.sign ()
+             && (alter.abs () < prev.abs ()
+                 || (prev * alter).sign () < 0))
+           result.need_restore = true;
+       }
+    }
 
-  SCM prev_acc = (prev == SCM_BOOL_F) ? scm_int2num (0) : ly_cdr (prev);
+  return result;
+}
 
-  int p = ly_c_number_p (prev_acc) ? ly_scm2int (prev_acc) : 0;
+// TODO: consider moving check_pitch_against_signature to SCM (in which case
+// we can delete this function).
+LY_DEFINE (ly_find_accidentals_simple, "ly:find-accidentals-simple", 5, 0, 0,
+          (SCM keysig, SCM pitch_scm, SCM barnum, SCM laziness, SCM octaveness ),
+          "Checks the need for an accidental and a @q{restore} accidental against a"
+          " key signature.  The @var{laziness} is the number of bars for which reminder"
+          " accidentals are used (ie. if @var{laziness} is zero, we only cancel accidentals"
+          " in the same bar; if @var{laziness} is three, we cancel accidentals up to three"
+          " bars after they first appear.  @var{octaveness} is either"
+          " @code{'same-octave} or @code{'any-octave} and it specifies whether"
+          " accidentals should be canceled in different octaves.")
+{
+  LY_ASSERT_TYPE (unsmob_pitch, pitch_scm, 2);
+  LY_ASSERT_TYPE (scm_is_integer, barnum, 3);
+  LY_ASSERT_TYPE (ly_is_symbol, octaveness, 5);
 
-  int num;
-  if (a == p && ly_c_number_p (prev_acc))
-    num = 0;
-  else if ( (abs (a)<abs (p) || p*a<0) && a != 0 )
-    num = 2;
-  else
-    num = 1;
+  bool symbol_ok = octaveness == ly_symbol2scm ("any-octave") ||
+    octaveness == ly_symbol2scm ("same-octave");
+
+  SCM_ASSERT_TYPE (symbol_ok, octaveness, SCM_ARG5, __FUNCTION__, "'any-octave or 'same-octave");
 
-  *different = (a != p);
-  return num;
+  Pitch *pitch = unsmob_pitch (pitch_scm);
+
+  int bar_number = scm_to_int (barnum);
+  bool ignore_octave = ly_symbol2scm ("any-octave") == octaveness; 
+  Accidental_result result = check_pitch_against_signature (keysig, *pitch, bar_number,
+                                                           laziness, ignore_octave);
+
+  return scm_cons (scm_from_bool (result.need_restore), scm_from_bool (result.need_acc));
 }
 
-static int
-number_accidentals (bool *different,
-                   Pitch *pitch, Context * origin, 
-                   SCM accidentals, SCM curbarnum)
+static
+Accidental_result
+check_pitch_against_rules (Pitch const &pitch, Context *origin,
+                          SCM rules, int bar_number, SCM measurepos)
 {
-  int number = 0;
+  Accidental_result result;
+  SCM pitch_scm = pitch.smobbed_copy ();
+  SCM barnum_scm = scm_from_int (bar_number);
 
-  *different = false;
-  if (ly_c_pair_p (accidentals) && !ly_c_symbol_p (ly_car (accidentals)))
-    warning (_f ("Accidental typesetting list must begin with context-name: %s", 
-                ly_scm2string (ly_car (accidentals)).to_str0 ()));
-  
-  for (; ly_c_pair_p (accidentals) && origin; accidentals = ly_cdr (accidentals))
+  if (scm_is_pair (rules) && !scm_is_symbol (scm_car (rules)))
+    warning (_f ("accidental typesetting list must begin with context-name: %s",
+                ly_scm2string (scm_car (rules)).c_str ()));
+
+  for (; scm_is_pair (rules) && origin;
+       rules = scm_cdr (rules))
     {
-      // If pair then it is a new accidentals typesetting rule to be checked
-      SCM rule = ly_car (accidentals);
-      if (ly_c_pair_p (rule))
+      SCM rule = scm_car (rules);
+      if (ly_is_procedure (rule))
        {
-         SCM type = ly_car (rule);
-         SCM lazyness = ly_cdr (rule);
-         SCM localsig = origin->get_property ("localKeySignature");
-         
-         bool same_octave_b = 
-           ly_c_eq_p (ly_symbol2scm ("same-octave"), type);
-         bool any_octave_b = 
-           ly_c_eq_p (ly_symbol2scm ("any-octave"), type);
-
-         if (same_octave_b || any_octave_b)
-           {
-             bool d = false;
-             int n = number_accidentals_from_sig
-               (&d, localsig, pitch, curbarnum, lazyness, any_octave_b);
-             *different = *different || d;
-             number = max (number, n);     
-           }
-         else
-           warning (_f ("ignoring unknown accidental: %s", 
-                        ly_symbol2string (type).to_str0 ()));
+         SCM rule_result_scm = scm_call_4 (rule, origin->self_scm (),
+                                           pitch_scm, barnum_scm, measurepos);
+
+         Accidental_result rule_result (rule_result_scm);
+
+         result.need_acc |= rule_result.need_acc;
+         result.need_restore |= rule_result.need_restore;
        }
-      
 
-      /*
-       if symbol then it is a context name. Scan parent contexts to find it.
-      */
-      else if (ly_c_symbol_p (rule))
+      /* if symbol then it is a context name.  Scan parent contexts to
+        find it. */
+      else if (scm_is_symbol (rule))
        {
-         Context * dad = origin;
+         Context *dad = origin;
          while (dad && !dad->is_alias (rule))
            dad = dad->get_parent_context ();
-      
+
          if (dad)
            origin = dad;
        }
-      else warning (_f ("Accidental rule must be pair or context-name; Found %s", 
-                       ly_scm2string (rule).to_str0 ()));
+      else
+       warning (_f ("procedure or context-name expected for accidental rule, found %s",
+                    print_scm_val (rule).c_str ()));
     }
 
-  return number;
-}
-
-SCM
-Accidental_engraver::get_bar_num ()
-{
-  SCM barnum = get_property ("currentBarNumber");
-  SCM smp = get_property ("measurePosition");
-      
-  Moment mp = (unsmob_moment (smp)) ? *unsmob_moment (smp) : Moment (0);
-  if (mp.main_part_ < Rational (0)
-      && ly_c_number_p (barnum))
-    barnum = scm_int2num (ly_scm2int (barnum) - 1);
-      
-  return barnum ;
+  return result;
 }
 
 void
-Accidental_engraver::process_acknowledged_grobs ()
+Accidental_engraver::process_acknowledged ()
 {
-  if (accidentals_.size () && !accidentals_.top ().done_)
+  if (accidentals_.size () && !accidentals_.back ().done_)
     {
-      SCM accidentals =  get_property ("autoAccidentals");
-      SCM cautionaries =  get_property ("autoCautionaries");
-      SCM barnum = get_bar_num ();
-      
-      bool extra_natural_b = get_property ("extraNatural") == SCM_BOOL_T;
-      for (int i = 0; i  < accidentals_.size (); i++) 
+      SCM accidental_rules = get_property ("autoAccidentals");
+      SCM cautionary_rules = get_property ("autoCautionaries");
+      SCM measure_position = get_property ("measurePosition");
+      int barnum = measure_number (context());
+
+      for (vsize i = 0; i < accidentals_.size (); i++)
        {
-         if (accidentals_[i].done_ )
+         if (accidentals_[i].done_)
            continue;
-         accidentals_[i].done_  = true;
-         Grob * support = accidentals_[i].head_;
-         Music * note = accidentals_[i].melodic_;
-         Context * origin = accidentals_[i].origin_;
+         accidentals_[i].done_ = true;
 
-         Pitch * pitch = unsmob_pitch (note->get_property ("pitch"));
+         Stream_event *note = accidentals_[i].melodic_;
+         Context *origin = accidentals_[i].origin_;
+
+         Pitch *pitch = unsmob_pitch (note->get_property ("pitch"));
          if (!pitch)
            continue;
 
-         bool different = false;
-         bool different_caut = false;
-         
-         int num = number_accidentals (&different,
-                                       pitch, origin,
-                                       accidentals, barnum);
-         int num_caut = number_accidentals (&different_caut,
-                                            pitch, origin,
-                                            cautionaries, barnum);
+         Accidental_result acc = check_pitch_against_rules (*pitch, origin, accidental_rules,
+                                                            barnum, measure_position);
+         Accidental_result caut = check_pitch_against_rules (*pitch, origin, cautionary_rules,
+                                                             barnum, measure_position);
 
          bool cautionary = to_boolean (note->get_property ("cautionary"));
-         
-         if (num_caut > num)
+         if (caut.score () > acc.score ())
            {
-             num = num_caut;
-             different = different_caut;
+             acc.need_acc |= caut.need_acc; 
+             acc.need_restore |= caut.need_restore; 
+
              cautionary = true;
            }
 
-         if (num == 0 && to_boolean (note->get_property ("force-accidental")))
-           num = 1;
-         
+         bool forced = to_boolean (note->get_property ("force-accidental"));
+         if (!acc.need_acc && forced)
+           acc.need_acc = true;
 
-         /*
-           Can not look for ties: it's not guaranteed that they reach
-           us before the notes
-          */
-       
-         if (num)
+         /* Cannot look for ties: it's not guaranteed that they reach
+            us before the notes. */
+         if (!note->in_event_class ("trill-span-event"))
            {
-             /*
-               We construct the accidentals at the originating Voice
-               level, so that we get the property settings for
-               Accidental from the respective Voice.
-              */
-             Grob * a = make_item_from_properties (origin->implementation (),
-                                                   ly_symbol2scm ("Accidental"),
-                                                   note->self_scm ()
-                                                   );
-             a->set_parent (support, Y_AXIS);
-
-             if (!accidental_placement_)
-               {
-                 accidental_placement_ = make_item ("AccidentalPlacement", a->self_scm ());
-               }
-             
-             Accidental_placement::add_accidental (accidental_placement_, a);
-
-             
-             SCM accs = scm_cons (scm_int2num (pitch->get_alteration ()), SCM_EOL);
-             if (num == 2 && extra_natural_b)
-               accs = scm_cons (scm_int2num (0), accs);
-
-             /* TODO:
-
-             add cautionary option in accidental.
-              */
-
-             if (cautionary)
-               {
-                 a->set_property ("cautionary", SCM_BOOL_T);
-               }
-             
-             
-             support->set_property ("accidental-grob", a->self_scm ());
-
-             a->set_property ("accidentals", accs);
-             accidentals_[i].accidental_ = a;
+             if (acc.need_acc)       
+               create_accidental (&accidentals_[i], acc.need_restore, cautionary);
 
-             /*
-               We add the accidentals to the support of the arpeggio,
-               so it is put left of the accidentals.
-             */
-             for (int i = 0;  i < left_objects_.size ();  i++)
-               Side_position_interface::add_support (left_objects_[i], a);
-             for (int i = 0;  i < right_objects_.size ();  i++)
-               Side_position_interface::add_support (a, right_objects_[i]);
+             if (forced || cautionary)
+               accidentals_[i].accidental_->set_property ("forced", SCM_BOOL_T);
            }
        }
     }
 }
 
+void
+Accidental_engraver::create_accidental (Accidental_entry *entry,
+                                       bool restore_natural,
+                                       bool cautionary)
+{
+  Stream_event *note = entry->melodic_;
+  Grob *support = entry->head_;
+  bool as_suggestion = to_boolean (entry->origin_->get_property ("suggestAccidentals"));
+  Grob *a = 0;
+  if (as_suggestion)
+    a = make_suggested_accidental (note, support, entry->origin_engraver_);
+  else
+    a = make_standard_accidental (note, support, entry->origin_engraver_, cautionary);
 
+  if (restore_natural)
+    {
+      if (to_boolean (get_property ("extraNatural")))
+       a->set_property ("restore-first", SCM_BOOL_T);
+    }
 
+  entry->accidental_ = a;
+}
+
+Grob *
+Accidental_engraver::make_standard_accidental (Stream_event * /* note */,
+                                              Grob *note_head,
+                                              Engraver *trans,
+                                              bool cautionary)
+{
+  /*
+    We construct the accidentals at the originating Voice
+    level, so that we get the property settings for
+    Accidental from the respective Voice.
+  */
+  Grob *a = 0;
+  if (cautionary)
+    a = trans->make_item ("AccidentalCautionary", note_head->self_scm ());
+  else
+    a = trans->make_item ("Accidental", note_head->self_scm ());
+
+  /*
+    We add the accidentals to the support of the arpeggio,
+    so it is put left of the accidentals.
+  */
+  for (vsize i = 0; i < left_objects_.size (); i++)
+    {
+      if (left_objects_[i]->get_property ("side-axis") == scm_from_int (X_AXIS))
+       Side_position_interface::add_support (left_objects_[i], a);
+    }
+
+  for (vsize i = 0; i < right_objects_.size (); i++)
+    Side_position_interface::add_support (a, right_objects_[i]);
+
+  a->set_parent (note_head, Y_AXIS);
+
+  if (!accidental_placement_)
+    accidental_placement_ = make_item ("AccidentalPlacement",
+                                      a->self_scm ());
+  Accidental_placement::add_accidental (accidental_placement_, a);
+
+  note_head->set_object ("accidental-grob", a->self_scm ());
+  
+  return a;
+}
+
+Grob *
+Accidental_engraver::make_suggested_accidental (Stream_event * /* note */,
+                                               Grob *note_head,
+                                               Engraver *trans)
+{
+  Grob *a = trans->make_item ("AccidentalSuggestion", note_head->self_scm ());
+
+  Side_position_interface::add_support (a, note_head);
+  if (Grob *stem = unsmob_grob (a->get_object ("stem")))
+    Side_position_interface::add_support (a, stem);
+
+  a->set_parent (note_head, X_AXIS);
+  return a;
+}
 
 void
 Accidental_engraver::finalize ()
@@ -346,54 +476,56 @@ Accidental_engraver::finalize ()
 void
 Accidental_engraver::stop_translation_timestep ()
 {
-  for (int j  = ties_.size (); j --; )
+  for (vsize j = ties_.size (); j--;)
     {
-      Grob * r = Tie::head (ties_[j], RIGHT);
-      for (int i = accidentals_.size ();  i--;)
+      Grob *r = Tie::head (ties_[j], RIGHT);
+      for (vsize i = accidentals_.size (); i--;)
        if (accidentals_[i].head_ == r)
          {
-           if (Grob * g = accidentals_[i].accidental_)
+           if (Grob *g = accidentals_[i].accidental_)
              {
-               g->set_property ("tie", ties_[j]->self_scm ());
-               accidentals_[i].tied_   = true;
+               g->set_object ("tie", ties_[j]->self_scm ());
+               accidentals_[i].tied_ = true;
              }
-           
-           ties_.del (j);
+           ties_.erase (ties_.begin () + j);
            break;
          }
     }
 
-  for (int i = accidentals_.size (); i--;) 
-    {
-      SCM barnum = get_bar_num ();
+  for (vsize i = accidentals_.size (); i--;)
+    {      
+      Stream_event *note = accidentals_[i].melodic_;
+      Context *origin = accidentals_[i].origin_;
 
-      Music * note = accidentals_[i].melodic_;
-      Context * origin = accidentals_[i].origin_;
+      int barnum = measure_number (origin);
 
-      Pitch * pitch = unsmob_pitch (note->get_property ("pitch"));
+      Pitch *pitch = unsmob_pitch (note->get_property ("pitch"));
       if (!pitch)
        continue;
-      
+
       int n = pitch->get_notename ();
       int o = pitch->get_octave ();
-      int a = pitch->get_alteration ();
-      SCM on_s = scm_cons (scm_int2num (o), scm_int2num (n));
+      Rational a = pitch->get_alteration ();
+      SCM key = scm_cons (scm_from_int (o), scm_from_int (n));
+
+      Moment end_mp = measure_position (context (),
+                                       unsmob_duration (note->get_property ("duration")));
+      SCM position = scm_cons (scm_from_int (barnum), end_mp.smobbed_copy ());
 
-      while (origin)
+      SCM localsig = SCM_EOL;
+      while (origin
+            && origin->where_defined (ly_symbol2scm ("localKeySignature"), &localsig))
        {
-         /*
-           huh? we set props all the way to the top? 
-         */
-         SCM localsig = origin->get_property ("localKeySignature");
          bool change = false;
-         if (accidentals_[i].tied_)
+         if (accidentals_[i].tied_
+             && !(to_boolean (accidentals_[i].accidental_->get_property ("forced"))))
            {
              /*
                Remember an alteration that is different both from
                that of the tied note and of the key signature.
              */
-             localsig = ly_assoc_front_x
-               (localsig, on_s, scm_cons (SCM_BOOL_T, barnum));
+             localsig = ly_assoc_prepend_x (localsig, key,scm_cons (ly_symbol2scm ("tied"),
+                                                                    position));
 
              change = true;
            }
@@ -403,105 +535,115 @@ Accidental_engraver::stop_translation_timestep ()
                not really really correct if there are more than one
                noteheads with the same notename.
              */
-             localsig = ly_assoc_front_x
-               (localsig, on_s, scm_cons (scm_int2num (a), barnum));
-
+             localsig = ly_assoc_prepend_x (localsig, key,
+                                            scm_cons (ly_rational2scm (a),
+                                                      position));
              change = true;
            }
 
          if (change)
-           origin->set_property ("localKeySignature",  localsig);
+           origin->set_property ("localKeySignature", localsig);
+
          origin = origin->get_parent_context ();
        }
     }
-  
-  for (int i = 0; i < accidentals_.size (); i++)
-    {
-      if (Grob *a = accidentals_[i].accidental_)
-       typeset_grob (a);
-    }
 
   if (accidental_placement_)
-    typeset_grob (accidental_placement_);
+    for (vsize i = 0; i < note_columns_.size (); i++)
+      Separation_item::add_conditional_item (note_columns_[i], accidental_placement_);
 
   accidental_placement_ = 0;
-  
   accidentals_.clear ();
   left_objects_.clear ();
   right_objects_.clear ();
 }
 
 void
-Accidental_engraver::acknowledge_grob (Grob_info info)
+Accidental_engraver::acknowledge_rhythmic_head (Grob_info info)
 {
-  Music * note =  info.music_cause ();
-
+  Stream_event *note = info.event_cause ();
   if (note
-      && note->is_mus_type ("note-event")
-      && Rhythmic_head::has_interface (info.grob_))
+      && (note->in_event_class ("note-event")
+         || note->in_event_class ("trill-span-event")))
     {
-      if (to_boolean ( get_property ("harmonicAccidentals"))
-         || !ly_c_equal_p (info.grob_->get_property ("style"),
-                         ly_symbol2scm ("harmonic")))
+      /*
+       string harmonics usually don't have accidentals.
+      */
+      if (info.grob ()->get_property ("style") != ly_symbol2scm ("harmonic")
+         || to_boolean (get_property ("harmonicAccidentals")))
        {
-         
-         Accidental_entry entry ;
-         entry.head_ = info.grob_;
-         entry.origin_ = info.origin_trans_->context ();
+         Accidental_entry entry;
+         entry.head_ = info.grob ();
+         entry.origin_engraver_ = dynamic_cast<Engraver *> (info.origin_translator ());
+         entry.origin_ = entry.origin_engraver_->context ();
          entry.melodic_ = note;
 
-         accidentals_.push (entry);
+         accidentals_.push_back (entry);
        }
     }
-  else if (Tie::has_interface (info.grob_))
-    {
-      ties_.push (dynamic_cast<Spanner*> (info.grob_));
-    }
-  else if (Arpeggio::has_interface (info.grob_))
-    {
-      left_objects_.push (info.grob_); 
-    }
-  else if (info.grob_->internal_has_interface (ly_symbol2scm ("finger-interface")))
-    {
-      left_objects_.push (info.grob_); 
-    }
 }
 
 void
-Accidental_engraver::process_music ()
+Accidental_engraver::acknowledge_tie (Grob_info info)
 {
-  SCM sig = get_property ("keySignature");
-
-  /* Detect key sig changes.
-     Update all parents and children
-  */
-  if (last_keysig_ != sig)
-    {
-      Context * trans_ = context ();
-      while (trans_)
-       {
-         trans_ -> set_property ("localKeySignature",  ly_deep_copy (sig));
-         trans_ = trans_->get_parent_context ();
-       }
-      set_property_on_children (context (),"localKeySignature", sig);
-
-      last_keysig_ = sig;
-    }
+  ties_.push_back (dynamic_cast<Spanner *> (info.grob ()));
 }
 
+void
+Accidental_engraver::acknowledge_note_column (Grob_info info)
+{
+  note_columns_.push_back (info.grob ());
+}
 
+void
+Accidental_engraver::acknowledge_arpeggio (Grob_info info)
+{
+  left_objects_.push_back (info.grob ());
+}
 
+void
+Accidental_engraver::acknowledge_finger (Grob_info info)
+{
+  left_objects_.push_back (info.grob ());
+}
 
+void
+Accidental_engraver::process_music ()
+{
+  SCM sig = get_property ("keySignature");
+  if (last_keysig_ != sig)
+    update_local_key_signature (sig);
+}
 
-ENTER_DESCRIPTION (Accidental_engraver,
-                  "Make accidentals.  Catches note heads, ties and notices key-change "
-                  "events.  This engraver usually lives at Staff level, but "
-                  "reads the settings for Accidental at @code{Voice} level, " 
-                  "so you can @code{\\override} them at @code{Voice}. "
-                  ,
-                  
-                  "Accidental",
-                  "",
-              "finger-interface rhythmic-head-interface tie-interface arpeggio-interface",
-              "localKeySignature harmonicAccidentals extraNatural autoAccidentals autoCautionaries",
-                  "localKeySignature");
+ADD_ACKNOWLEDGER (Accidental_engraver, arpeggio);
+ADD_ACKNOWLEDGER (Accidental_engraver, finger);
+ADD_ACKNOWLEDGER (Accidental_engraver, rhythmic_head);
+ADD_ACKNOWLEDGER (Accidental_engraver, tie);
+ADD_ACKNOWLEDGER (Accidental_engraver, note_column);
+
+ADD_TRANSLATOR (Accidental_engraver,
+               /* doc */
+               "Make accidentals."
+               "  Catch note heads, ties and notices key-change events."
+               "  This engraver usually lives at Staff level, but"
+               " reads the settings for Accidental at @code{Voice} level,"
+               " so you can @code{\\override} them at @code{Voice}.",
+
+               /* create */
+               "Accidental "
+               "AccidentalCautionary "
+               "AccidentalPlacement "
+               "AccidentalSuggestion ",
+
+               /* read */
+               "autoAccidentals "
+               "autoCautionaries "
+               "internalBarNumber "
+               "extraNatural "
+               "harmonicAccidentals "
+               "keySignature "
+               "localKeySignature ",
+
+               /* write */
+               "localKeySignature "
+               );