lily/metronome-engraver.cc

   1 /*
   2   mark-engraver.cc -- implement Metronome_mark_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1998--2006 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include <cctype>
  10 using namespace std;
  11
  12 #include "engraver.hh"
  13
  14 #include "item.hh"
  15 #include "context.hh"
  16 #include "grob-array.hh"
  17 #include "duration.hh"
  18
  19 /**
  20    put stuff over or next to  bars.  Examples: bar numbers, marginal notes,
  21    rehearsal marks.
  22 */
  23 class Metronome_mark_engraver : public Engraver
  24 {
  25 public:
  26   TRANSLATOR_DECLARATIONS (Metronome_mark_engraver);
  27 protected:
  28   Item *text_;
  29   Grob *bar_line_;
  30
  31   SCM last_duration_;
  32   SCM last_count_;
  33
  34 protected:
  35   virtual void derived_mark () const;
  36   void stop_translation_timestep ();
  37   void process_music ();
  38 };
  39
  40 Metronome_mark_engraver::Metronome_mark_engraver ()
  41 {
  42   text_ = 0;
  43   last_duration_ = SCM_EOL;
  44   last_count_ = SCM_EOL;
  45 }
  46
  47 void
  48 Metronome_mark_engraver::derived_mark () const
  49 {
  50   scm_gc_mark (last_count_);
  51   scm_gc_mark (last_duration_);
  52 }
  53
  54 void
  55 Metronome_mark_engraver::stop_translation_timestep ()
  56 {
  57   if (text_)
  58     {
  59       Grob *mc = unsmob_grob (get_property ("currentMusicalColumn"));
  60       text_->set_parent (mc, X_AXIS);
  61       text_->set_object ("side-support-elements",
  62                          grob_list_to_grob_array (get_property ("stavesFound")));
  63
  64       text_ = 0;
  65     }
  66 }
  67
  68 void
  69 Metronome_mark_engraver::process_music ()
  70 {
  71   SCM count = get_property ("tempoUnitCount");
  72   SCM duration = get_property ("tempoUnitDuration");
  73
  74   if (unsmob_duration (duration)
  75       && scm_is_number (count)
  76       && !(ly_is_equal (count, last_count_)
  77            && ly_is_equal (duration, last_duration_)))
  78     {
  79       text_ = make_item ("MetronomeMark", SCM_EOL);
  80
  81       SCM proc = get_property ("metronomeMarkFormatter");
  82       SCM result = scm_call_3 (proc,
  83                                duration,
  84                                count,
  85                                context ()->self_scm ());
  86
  87       text_->set_property ("text", result);
  88     }
  89
  90   last_duration_ = duration;
  91   last_count_ = count;
  92 }
  93
  94 #include "translator.icc"
  95
  96 ADD_TRANSLATOR (Metronome_mark_engraver,
  97                 /* doc */ "Engrave metro nome marking. This delegates the formatting work "
  98                 "to the function in the metronomeMarkFormatter property. "
  99                 "The mark is put over all staves. "
 100                 "The staves are taken from the @code{stavesFound} property, "
 101                 "which is maintained by @code{@ref{Staff_collecting_engraver}}. ",
 102                 /* create */ "MetronomeMark",
 103                 /* accept */ "",
 104
 105                 /* read */
 106                 "stavesFound "
 107                 "metronomeMarkFormatter "
 108                 "tempoUnitDuration "
 109                 "tempoUnitCount "
 110                 ,
 111
 112                 /* write */ "");