lily/metronome-engraver.cc

   1 /*
   2   metronome-engraver.cc -- implement Metronome_mark_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1998--2008 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 #include "text-interface.hh"
  20
  21 #include "translator.icc"
  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   SCM last_text_;
  34
  35 protected:
  36   virtual void derived_mark () const;
  37   void stop_translation_timestep ();
  38   void process_music ();
  39 };
  40
  41 Metronome_mark_engraver::Metronome_mark_engraver ()
  42 {
  43   text_ = 0;
  44   last_duration_ = SCM_EOL;
  45   last_count_ = SCM_EOL;
  46   last_text_ = SCM_EOL;
  47 }
  48
  49 void
  50 Metronome_mark_engraver::derived_mark () const
  51 {
  52   scm_gc_mark (last_count_);
  53   scm_gc_mark (last_duration_);
  54   scm_gc_mark (last_text_);
  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   SCM text = get_property ("tempoText");
  76
  77   if ( ( (unsmob_duration (duration) && scm_is_number (count))
  78         || Text_interface::is_markup (text) )
  79       && !(ly_is_equal (count, last_count_)
  80            && ly_is_equal (duration, last_duration_)
  81            && ly_is_equal (text, last_text_)))
  82     {
  83       text_ = make_item ("MetronomeMark", SCM_EOL);
  84
  85       SCM proc = get_property ("metronomeMarkFormatter");
  86       SCM result = scm_call_4 (proc,
  87                                text,
  88                                duration,
  89                                count,
  90                                context ()->self_scm ());
  91
  92       text_->set_property ("text", result);
  93     }
  94
  95   last_duration_ = duration;
  96   last_count_ = count;
  97   last_text_ = text;
  98 }
  99
 100 ADD_TRANSLATOR (Metronome_mark_engraver,
 101                 /* doc */
 102                 "Engrave metronome marking.  This delegates the formatting"
 103                 " work to the function in the @code{metronomeMarkFormatter}"
 104                 " property.  The mark is put over all staves.  The staves are"
 105                 " taken from the @code{stavesFound} property, which is"
 106                 " maintained by @ref{Staff_collecting_engraver}.",
 107
 108                 /* create */
 109                 "MetronomeMark ",
 110
 111                 /* read */
 112                 "stavesFound "
 113                 "metronomeMarkFormatter "
 114                 "tempoUnitDuration "
 115                 "tempoUnitCount "
 116                 "tempoText "
 117                 "tempoHideNote ",
 118
 119                 /* write */
 120                 ""
 121                 );