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--2007 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include <cctype>
  10 using namespace std;
  11
  12 #include "engraver.hh"
  13
  14 #include "context.hh"
  15 #include "duration.hh"
  16 #include "grob-array.hh"
  17 #include "item.hh"
  18 #include "stream-event.hh"
  19
  20 #include "translator.icc"
  21
  22 /**
  23    put stuff over or next to  bars.  Examples: bar numbers, marginal notes,
  24    rehearsal marks.
  25 */
  26 class Metronome_mark_engraver : public Engraver
  27 {
  28 public:
  29   TRANSLATOR_DECLARATIONS (Metronome_mark_engraver);
  30 protected:
  31   Item *text_;
  32   Grob *bar_line_;
  33
  34   SCM last_duration_;
  35   SCM last_count_;
  36
  37 protected:
  38   virtual void derived_mark () const;
  39   void stop_translation_timestep ();
  40   void process_music ();
  41 };
  42
  43 Metronome_mark_engraver::Metronome_mark_engraver ()
  44 {
  45   text_ = 0;
  46   last_duration_ = SCM_EOL;
  47   last_count_ = SCM_EOL;
  48 }
  49
  50 void
  51 Metronome_mark_engraver::derived_mark () const
  52 {
  53   scm_gc_mark (last_count_);
  54   scm_gc_mark (last_duration_);
  55 }
  56
  57 void
  58 Metronome_mark_engraver::stop_translation_timestep ()
  59 {
  60   if (text_)
  61     {
  62       Grob *mc = unsmob_grob (get_property ("currentMusicalColumn"));
  63       text_->set_parent (mc, X_AXIS);
  64       text_->set_object ("side-support-elements",
  65                          grob_list_to_grob_array (get_property ("stavesFound")));
  66       text_ = 0;
  67     }
  68 }
  69
  70 void
  71 Metronome_mark_engraver::process_music ()
  72 {
  73   SCM count = get_property ("tempoUnitCount");
  74   SCM duration = get_property ("tempoUnitDuration");
  75
  76   if (unsmob_duration (duration)
  77       && scm_is_number (count)
  78       && !(ly_is_equal (count, last_count_)
  79            && ly_is_equal (duration, last_duration_)))
  80     {
  81       text_ = make_item ("MetronomeMark", SCM_EOL);
  82
  83       SCM proc = get_property ("metronomeMarkFormatter");
  84       SCM result = scm_call_3 (proc,
  85                                duration,
  86                                count,
  87                                context ()->self_scm ());
  88
  89       text_->set_property ("text", result);
  90     }
  91
  92   last_duration_ = duration;
  93   last_count_ = count;
  94 }
  95
  96 ADD_TRANSLATOR (Metronome_mark_engraver,
  97                 /* doc */
  98                 "Engrave metronome marking.  This delegates the formatting"
  99                 " work to the function in the @code{metronomeMarkFormatter}"
 100                 " property.  The mark is put over all staves.  The staves are"
 101                 " taken from the @code{stavesFound} property, which is"
 102                 " maintained by @ref{Staff_collecting_engraver}.",
 103
 104                 /* create */
 105                 "MetronomeMark ",
 106
 107                 /* read */
 108                 "stavesFound "
 109                 "metronomeMarkFormatter "
 110                 "tempoUnitDuration "
 111                 "tempoUnitCount ",
 112
 113                 /* write */
 114                 ""
 115                 );