lily/ligature-engraver.cc

   1 /*
   2   ligature-engraver.cc -- implement Ligature_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2002--2003 Juergen Reuter <reuter@ipd.uka.de>
   7
   8  */
   9 #include "ligature-engraver.hh"
  10 #include "ligature-head.hh"
  11 #include "spanner.hh"
  12 #include "score-engraver.hh"
  13 #include "note-head.hh"
  14 #include "rest.hh"
  15 #include "warn.hh"
  16
  17 /*
  18  * TODO: lyrics/melisma/syllables: there should be at most one
  19  * syllable of lyrics per ligature (i.e. for the lyrics context, a
  20  * ligature should count as a single note, regardless of how many
  21  * heads the ligature consists of).
  22  *
  23  * TODO: currently, you have to add/remove the proper
  24  * Ligature_engraver (Ligature_bracket_engraver,
  25  * Mensural_ligature_engraver) to the proper translator
  26  * (e.g. VoiceContext) to choose between various representations.
  27  * Since adding/removing an engraver to a translator is a global
  28  * action in the paper block, you can not mix various representations
  29  * _within_ the same score.  Hence, for selecting a representation,
  30  * one would rather like to have a property that can be set e.g. for
  31  * several staves individually.  However, it seems that this approach
  32  * would require to have a single, complicated Ligature_engraver that
  33  * consists of all the code...  This needs further thoughts.
  34  */
  35 Ligature_engraver::Ligature_engraver ()
  36 {
  37   ligature_ = 0;
  38   finished_ligature_ = 0;
  39   reqs_drul_[LEFT] = reqs_drul_[RIGHT] = 0;
  40   prev_start_req_ = 0;
  41   last_bound_ = 0;
  42   brew_ligature_primitive_proc = SCM_EOL;
  43 }
  44
  45 bool
  46 Ligature_engraver::try_music (Music *m)
  47 {
  48   if (m->is_mus_type ("abort-event"))
  49     {
  50       reqs_drul_[START] = 0;
  51       reqs_drul_[STOP] = 0;
  52       if (ligature_)
  53         ligature_->suicide ();
  54       ligature_ = 0;
  55     }
  56   else if (m->is_mus_type ("ligature-event"))
  57     {
  58       Direction d = to_dir (m->get_mus_property ("span-direction"));
  59       reqs_drul_[d] = m;
  60       return true;
  61     }
  62   return false;
  63 }
  64
  65 Spanner *
  66 Ligature_engraver::create_ligature_spanner ()
  67 {
  68   programming_error ("Ligature_engraver::create_ligature_spanner (): "
  69                      "this is an abstract method that should not be called, "
  70                      "but overridden by a subclass");
  71   return 0;
  72 }
  73
  74 void
  75 Ligature_engraver::process_music ()
  76 {
  77   if (reqs_drul_[STOP])
  78     {
  79       if (!ligature_)
  80         reqs_drul_[STOP]->origin ()->warning (_ ("can't find start of ligature"));
  81       else
  82         {
  83           if (!last_bound_)
  84             {
  85               reqs_drul_[STOP]->origin ()->warning (_ ("no right bound"));
  86             }
  87           else
  88             {
  89               ligature_->set_bound (RIGHT, last_bound_);
  90             }
  91         }
  92       prev_start_req_ = 0;
  93       finished_primitives_ = primitives_;
  94       finished_ligature_ = ligature_;
  95       primitives_.clear ();
  96       ligature_ = 0;
  97     }
  98   last_bound_ = unsmob_grob (get_property ("currentMusicalColumn"));
  99
 100   if (ligature_)
 101     {
 102       // TODO: maybe forbid breaks only if not transcribing
 103       top_engraver ()->forbid_breaks ();
 104     }
 105   if (reqs_drul_[START])
 106     {
 107       if (ligature_)
 108         {
 109           reqs_drul_[START]->origin ()->warning (_ ("already have a ligature"));
 110           return;
 111         }
 112
 113       prev_start_req_ = reqs_drul_[START];
 114       ligature_ = create_ligature_spanner ();
 115       brew_ligature_primitive_proc =
 116         ligature_->get_grob_property ("ligature-primitive-callback");
 117       if (brew_ligature_primitive_proc == SCM_EOL)
 118         {
 119           warning ("Ligature_engraver: ligature-primitive-callback undefined");
 120         }
 121
 122       Grob *bound = unsmob_grob (get_property ("currentMusicalColumn"));
 123       if (!bound)
 124         {
 125           reqs_drul_[START]->origin ()->warning (_ ("no left bound"));
 126         }
 127       else
 128         {
 129           ligature_->set_bound (LEFT, bound);
 130         }
 131
 132       ligature_start_mom_ = now_mom ();
 133
 134       announce_grob(ligature_, reqs_drul_[START]->self_scm());
 135     }
 136 }
 137
 138 void
 139 Ligature_engraver::start_translation_timestep ()
 140 {
 141   reqs_drul_[START] = 0;
 142   reqs_drul_[STOP] = 0;
 143 }
 144
 145 void
 146 Ligature_engraver::typeset_ligature (Spanner *, Array<Grob_info>)
 147 {
 148   programming_error ("Ligature_engraver::typeset_ligature (): "
 149                      "this is an abstract method that should not be called, "
 150                      "but overridden by a subclass");
 151 }
 152
 153 void
 154 Ligature_engraver::stop_translation_timestep ()
 155 {
 156   if (finished_ligature_)
 157     {
 158       typeset_ligature (finished_ligature_, finished_primitives_);
 159       finished_primitives_.clear ();
 160       finished_ligature_ = 0;
 161     }
 162 }
 163
 164 void
 165 Ligature_engraver::finalize ()
 166 {
 167   if (finished_ligature_)
 168     {
 169       typeset_ligature (finished_ligature_, finished_primitives_);
 170       finished_primitives_.clear ();
 171       finished_ligature_ = 0;
 172     }
 173   if (ligature_)
 174     {
 175       prev_start_req_->origin ()->warning (_ ("unterminated ligature"));
 176       ligature_->suicide ();
 177     }
 178 }
 179
 180 Spanner *
 181 Ligature_engraver::current_ligature ()
 182 {
 183   return ligature_;
 184 }
 185
 186 void
 187 Ligature_engraver::acknowledge_grob (Grob_info info)
 188 {
 189   if (ligature_)
 190     {
 191       if (Note_head::has_interface (info.grob_))
 192         {
 193           primitives_.push (info);
 194         }
 195       if (Ligature_head::has_interface (info.grob_))
 196         {
 197           info.grob_->set_grob_property ("ligature-primitive-callback",
 198                                          brew_ligature_primitive_proc);
 199         }
 200       else if (Rest::has_interface (info.grob_))
 201         {
 202           info.music_cause ()->origin ()->warning (_ ("ligature may not contain rest; ignoring rest"));
 203           prev_start_req_->origin ()->warning (_ ("ligature was started here"));
 204           // TODO: maybe better should stop ligature here rather than
 205           // ignoring the rest?
 206         }
 207     }
 208 }
 209
 210 ENTER_DESCRIPTION (Ligature_engraver,
 211 /* descr */       "Abstract class; a concrete subclass handles Ligature_events by engraving Ligatures in a concrete style.",
 212 /* creats */      "",
 213 /* accepts */     "ligature-event abort-event",
 214 /* acks  */      "ligature-head-interface rest-interface",
 215 /* reads */       "",
 216 /* write */       "");