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 #include "text-interface.hh"
  20
  21 #include "translator.icc"
  22
  23 /**
  24    put stuff over or next to  bars.  Examples: bar numbers, marginal notes,
  25    rehearsal marks.
  26 */
  27 class Metronome_mark_engraver : public Engraver
  28 {
  29 public:
  30   TRANSLATOR_DECLARATIONS (Metronome_mark_engraver);
  31 protected:
  32   Item *text_;
  33   Grob *bar_line_;
  34
  35   SCM last_duration_;
  36   SCM last_count_;
  37   SCM last_text_;
  38
  39 protected:
  40   virtual void derived_mark () const;
  41   void stop_translation_timestep ();
  42   void process_music ();
  43 };
  44
  45 Metronome_mark_engraver::Metronome_mark_engraver ()
  46 {
  47   text_ = 0;
  48   last_duration_ = SCM_EOL;
  49   last_count_ = SCM_EOL;
  50 }
  51
  52 void
  53 Metronome_mark_engraver::derived_mark () const
  54 {
  55   scm_gc_mark (last_count_);
  56   scm_gc_mark (last_duration_);
  57   scm_gc_mark (last_text_);
  58 }
  59
  60 void
  61 Metronome_mark_engraver::stop_translation_timestep ()
  62 {
  63   if (text_)
  64     {
  65       Grob *mc = unsmob_grob (get_property ("currentMusicalColumn"));
  66       text_->set_parent (mc, X_AXIS);
  67       text_->set_object ("side-support-elements",
  68                          grob_list_to_grob_array (get_property ("stavesFound")));
  69       text_ = 0;
  70     }
  71 }
  72
  73 void
  74 Metronome_mark_engraver::process_music ()
  75 {
  76   SCM count = get_property ("tempoUnitCount");
  77   SCM duration = get_property ("tempoUnitDuration");
  78   SCM text = get_property ("tempoText");
  79
  80   if ( ( (unsmob_duration (duration) && scm_is_number (count))
  81         || Text_interface::is_markup (text) )
  82       && !(ly_is_equal (count, last_count_)
  83            && ly_is_equal (duration, last_duration_)
  84            && ly_is_equal (text, last_text_)))
  85     {
  86       text_ = make_item ("MetronomeMark", SCM_EOL);
  87
  88       SCM proc = get_property ("metronomeMarkFormatter");
  89       SCM result = scm_call_4 (proc,
  90                                text,
  91                                duration,
  92                                count,
  93                                context ()->self_scm ());
  94
  95       text_->set_property ("text", result);
  96     }
  97
  98   last_duration_ = duration;
  99   last_count_ = count;
 100   last_text_ = text;
 101 }
 102
 103 ADD_TRANSLATOR (Metronome_mark_engraver,
 104                 /* doc */
 105                 "Engrave metronome marking.  This delegates the formatting"
 106                 " work to the function in the @code{metronomeMarkFormatter}"
 107                 " property.  The mark is put over all staves.  The staves are"
 108                 " taken from the @code{stavesFound} property, which is"
 109                 " maintained by @ref{Staff_collecting_engraver}.",
 110
 111                 /* create */
 112                 "MetronomeMark ",
 113
 114                 /* read */
 115                 "stavesFound "
 116                 "metronomeMarkFormatter "
 117                 "tempoUnitDuration "
 118                 "tempoUnitCount "
 119                 "tempoText "
 120                 "tempoHideNote ",
 121
 122                 /* write */
 123                 ""
 124                 );