lily/metronome-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1998--2010 Jan Nieuwenhuizen <janneke@gnu.org>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include <cctype>
  21 using namespace std;
  22
  23 #include "engraver.hh"
  24
  25 #include "context.hh"
  26 #include "duration.hh"
  27 #include "grob-array.hh"
  28 #include "item.hh"
  29 #include "stream-event.hh"
  30 #include "text-interface.hh"
  31
  32 #include "translator.icc"
  33
  34 class Metronome_mark_engraver : public Engraver
  35 {
  36 public:
  37   TRANSLATOR_DECLARATIONS (Metronome_mark_engraver);
  38
  39 protected:
  40   Item *text_;
  41   Grob *support_;
  42
  43   SCM last_duration_;
  44   SCM last_count_;
  45   SCM last_text_;
  46
  47   DECLARE_ACKNOWLEDGER (break_aligned);
  48   DECLARE_ACKNOWLEDGER (grob);
  49
  50 protected:
  51   virtual void derived_mark () const;
  52   void stop_translation_timestep ();
  53   void process_music ();
  54 };
  55
  56 Metronome_mark_engraver::Metronome_mark_engraver ()
  57 {
  58   text_ = 0;
  59   support_ = 0;
  60   last_duration_ = SCM_EOL;
  61   last_count_ = SCM_EOL;
  62   last_text_ = SCM_EOL;
  63 }
  64
  65 void
  66 Metronome_mark_engraver::derived_mark () const
  67 {
  68   scm_gc_mark (last_count_);
  69   scm_gc_mark (last_duration_);
  70   scm_gc_mark (last_text_);
  71 }
  72
  73 void
  74 Metronome_mark_engraver::acknowledge_break_aligned (Grob_info info)
  75 {
  76   Grob *g = info.grob ();
  77   if (text_
  78       && !support_
  79       && (g->get_property_data ("break-align-symbol")
  80           == text_->get_property_data ("break-align-symbol")))
  81     {
  82       support_ = g;
  83       text_->set_parent (g, X_AXIS);
  84     }
  85 }
  86
  87 SCM
  88 grob_name_scm (Grob *g)
  89 {
  90   SCM name_pair = scm_assq (ly_symbol2scm ("name"), g->get_property ("meta"));
  91   return scm_is_pair (name_pair) ? scm_cdr (name_pair) : SCM_EOL;
  92 }
  93
  94 void
  95 Metronome_mark_engraver::acknowledge_grob (Grob_info info)
  96 {
  97   Grob *g = info.grob ();
  98
  99   if (text_
 100       && !support_
 101       && scm_member (grob_name_scm (g),
 102                      text_->get_property_data ("non-break-align-symbols"))
 103       != SCM_BOOL_F)
 104     {
 105       text_->set_parent (g, X_AXIS);
 106     }
 107 }
 108
 109 void
 110 Metronome_mark_engraver::stop_translation_timestep ()
 111 {
 112   if (text_)
 113     {
 114       if (!support_)
 115         {
 116           /*
 117             Gardner Read "Music Notation", p.278
 118
 119             Align the metronome mark over the time signature (or the
 120             first notational element of the measure if no time
 121             signature is present in that measure).
 122           */
 123           if (Grob *mc = unsmob_grob (get_property ("currentMusicalColumn")))
 124             text_->set_parent (mc, X_AXIS);
 125           else if (Grob *cc = unsmob_grob (get_property ("currentCommandColumn")))
 126             text_->set_parent (cc, X_AXIS);
 127         }
 128       text_->set_object ("side-support-elements",
 129                          grob_list_to_grob_array (get_property ("stavesFound")));
 130       text_ = 0;
 131       support_ = 0;
 132     }
 133 }
 134
 135 void
 136 Metronome_mark_engraver::process_music ()
 137 {
 138   SCM count = get_property ("tempoUnitCount");
 139   SCM duration = get_property ("tempoUnitDuration");
 140   SCM text = get_property ("tempoText");
 141
 142   if ( ( (unsmob_duration (duration) && scm_is_number (count))
 143         || Text_interface::is_markup (text) )
 144       && !(ly_is_equal (count, last_count_)
 145            && ly_is_equal (duration, last_duration_)
 146            && ly_is_equal (text, last_text_)))
 147     {
 148       text_ = make_item ("MetronomeMark", SCM_EOL);
 149
 150       SCM proc = get_property ("metronomeMarkFormatter");
 151       SCM result = scm_call_4 (proc,
 152                                text,
 153                                duration,
 154                                count,
 155                                context ()->self_scm ());
 156
 157       text_->set_property ("text", result);
 158     }
 159
 160   last_duration_ = duration;
 161   last_count_ = count;
 162   last_text_ = text;
 163 }
 164
 165
 166
 167 ADD_ACKNOWLEDGER (Metronome_mark_engraver, break_aligned);
 168 ADD_ACKNOWLEDGER (Metronome_mark_engraver, grob);
 169
 170 ADD_TRANSLATOR (Metronome_mark_engraver,
 171                 /* doc */
 172                 "Engrave metronome marking.  This delegates the formatting"
 173                 " work to the function in the @code{metronomeMarkFormatter}"
 174                 " property.  The mark is put over all staves.  The staves are"
 175                 " taken from the @code{stavesFound} property, which is"
 176                 " maintained by @ref{Staff_collecting_engraver}.",
 177
 178                 /* create */
 179                 "MetronomeMark ",
 180
 181                 /* read */
 182                 "stavesFound "
 183                 "metronomeMarkFormatter "
 184                 "tempoUnitDuration "
 185                 "tempoUnitCount "
 186                 "tempoText "
 187                 "tempoHideNote ",
 188
 189                 /* write */
 190                 ""
 191                 );