lily/metronome-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1998--2011 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 "music.hh"
  30 #include "stream-event.hh"
  31 #include "text-interface.hh"
  32
  33 #include "translator.icc"
  34
  35 class Metronome_mark_engraver : public Engraver
  36 {
  37   Item *text_;
  38   Grob *support_;
  39   Grob *bar_;
  40   Stream_event *tempo_ev_;
  41
  42 public:
  43   TRANSLATOR_DECLARATIONS (Metronome_mark_engraver);
  44
  45 protected:
  46   void stop_translation_timestep ();
  47   void process_music ();
  48
  49   DECLARE_ACKNOWLEDGER (break_aligned);
  50   DECLARE_ACKNOWLEDGER (break_alignment);
  51   DECLARE_ACKNOWLEDGER (grob);
  52
  53   DECLARE_TRANSLATOR_LISTENER (tempo_change);
  54 };
  55
  56 Metronome_mark_engraver::Metronome_mark_engraver ()
  57 {
  58   text_ = 0;
  59   support_ = 0;
  60   bar_ = 0;
  61   tempo_ev_ = 0;
  62 }
  63
  64 IMPLEMENT_TRANSLATOR_LISTENER (Metronome_mark_engraver, tempo_change);
  65 void
  66 Metronome_mark_engraver::listen_tempo_change (Stream_event *ev)
  67 {
  68   ASSIGN_EVENT_ONCE (tempo_ev_, ev);
  69 }
  70
  71 static bool
  72 safe_is_member (SCM scm, SCM lst)
  73 {
  74   return scm_list_p (lst) == SCM_BOOL_T
  75     && scm_member (scm, lst) != SCM_BOOL_F;
  76 }
  77
  78 void
  79 Metronome_mark_engraver::acknowledge_break_aligned (Grob_info info)
  80 {
  81   Grob *g = info.grob ();
  82
  83   if (text_
  84       && g->get_property ("break-align-symbol")
  85       == ly_symbol2scm ("staff-bar"))
  86     bar_ = g;
  87   else if (text_
  88            && !support_
  89            && safe_is_member (g->get_property ("break-align-symbol"),
  90                               text_->get_property ("break-align-symbols"))
  91            && Item::break_visible (g))
  92     {
  93       support_ = g;
  94       text_->set_parent (g, X_AXIS);
  95     }
  96 }
  97
  98 void
  99 Metronome_mark_engraver::acknowledge_break_alignment (Grob_info info)
 100 {
 101   Grob *g = info.grob ();
 102
 103   if (text_
 104       && support_
 105       && dynamic_cast<Item *> (g))
 106     text_->set_parent (g, X_AXIS);
 107 }
 108
 109 void
 110 Metronome_mark_engraver::acknowledge_grob (Grob_info info)
 111 {
 112   Grob *g = info.grob ();
 113
 114   if (text_)
 115     for (SCM s = text_->get_property ("non-break-align-symbols");
 116          scm_is_pair (s);
 117          s = scm_cdr (s))
 118       if (g->internal_has_interface (scm_car (s)))
 119         text_->set_parent (g, X_AXIS);
 120 }
 121
 122 void
 123 Metronome_mark_engraver::stop_translation_timestep ()
 124 {
 125   if (text_)
 126     {
 127       if (text_->get_parent (X_AXIS)
 128           && text_->get_parent (X_AXIS)->internal_has_interface (ly_symbol2scm ("multi-measure-rest-interface"))
 129           && bar_)
 130         text_->set_parent (bar_, X_AXIS);
 131       else if (!support_)
 132         {
 133           /*
 134             Gardner Read "Music Notation", p.278
 135
 136             Align the metronome mark over the time signature (or the
 137             first notational element of the measure if no time
 138             signature is present in that measure).
 139           */
 140           if (Grob *mc = unsmob_grob (get_property ("currentMusicalColumn")))
 141             text_->set_parent (mc, X_AXIS);
 142           else if (Grob *cc = unsmob_grob (get_property ("currentCommandColumn")))
 143             text_->set_parent (cc, X_AXIS);
 144         }
 145       text_->set_object ("side-support-elements",
 146                          grob_list_to_grob_array (get_property ("stavesFound")));
 147       text_ = 0;
 148       support_ = 0;
 149       bar_ = 0;
 150       tempo_ev_ = 0;
 151     }
 152 }
 153
 154 void
 155 Metronome_mark_engraver::process_music ()
 156 {
 157   if (tempo_ev_)
 158     {
 159       text_ = make_item ("MetronomeMark", tempo_ev_->self_scm ());
 160
 161       SCM proc = get_property ("metronomeMarkFormatter");
 162       SCM result = scm_call_2 (proc,
 163                                tempo_ev_->self_scm (),
 164                                context ()->self_scm ());
 165
 166       text_->set_property ("text", result);
 167     }
 168 }
 169
 170 ADD_ACKNOWLEDGER (Metronome_mark_engraver, break_aligned);
 171 ADD_ACKNOWLEDGER (Metronome_mark_engraver, break_alignment);
 172 ADD_ACKNOWLEDGER (Metronome_mark_engraver, grob);
 173
 174 ADD_TRANSLATOR (Metronome_mark_engraver,
 175                 /* doc */
 176                 "Engrave metronome marking.  This delegates the formatting"
 177                 " work to the function in the @code{metronomeMarkFormatter}"
 178                 " property.  The mark is put over all staves.  The staves are"
 179                 " taken from the @code{stavesFound} property, which is"
 180                 " maintained by @ref{Staff_collecting_engraver}.",
 181
 182                 /* create */
 183                 "MetronomeMark ",
 184
 185                 /* read */
 186                 "currentCommandColumn "
 187                 "currentMusicalColumn "
 188                 "metronomeMarkFormatter "
 189                 "stavesFound "
 190                 "tempoHideNote ",
 191
 192                 /* write */
 193                 ""
 194                 );