lily/bend-engraver.cc

   1 /*
   2   bend-engraver.cc -- implement Bend_engraver
   3
   4   (c) 2006--2009 Han-Wen Nienhuys
   5
   6
   7 */
   8
   9 #include "engraver.hh"
  10 #include "item.hh"
  11 #include "moment.hh"
  12 #include "spanner.hh"
  13 #include "stream-event.hh"
  14
  15 #include "translator.icc"
  16
  17 class Bend_engraver : public Engraver
  18 {
  19 public:
  20   TRANSLATOR_DECLARATIONS (Bend_engraver);
  21   DECLARE_ACKNOWLEDGER (note_head);
  22
  23 protected:
  24   DECLARE_TRANSLATOR_LISTENER (bend_after);
  25   void finalize ();
  26   void process_music ();
  27   void stop_translation_timestep ();
  28   void start_translation_timestep ();
  29   void stop_fall ();
  30
  31 private:
  32   Moment stop_moment_;
  33   Stream_event *fall_event_;
  34   Spanner *fall_;
  35   Spanner *last_fall_;
  36   Grob *note_head_;
  37 };
  38
  39 void
  40 Bend_engraver::finalize ()
  41 {
  42   // We shouldn't end a spanner on the last musical column of a piece because then
  43   // it would extend past the last breakable column of the piece.
  44   if (last_fall_)
  45     last_fall_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
  46 }
  47
  48 void
  49 Bend_engraver::stop_fall ()
  50 {
  51   bool bar = scm_is_string (get_property ("whichBar"));
  52
  53
  54   fall_->set_bound (RIGHT, unsmob_grob (bar
  55                                         ? get_property ("currentCommandColumn")
  56                                         : get_property ("currentMusicalColumn")));
  57   last_fall_ = fall_;
  58   fall_ = 0;
  59   note_head_ = 0;
  60   fall_event_ = 0;
  61 }
  62
  63 void
  64 Bend_engraver::stop_translation_timestep ()
  65 {
  66   if (fall_ && !fall_->get_bound (LEFT))
  67     {
  68       fall_->set_bound (LEFT, note_head_);
  69       fall_->set_parent (note_head_,  Y_AXIS);
  70     }
  71 }
  72
  73 void
  74 Bend_engraver::start_translation_timestep ()
  75 {
  76   last_fall_ = 0;
  77
  78   if (fall_ && now_mom ().main_part_ >= stop_moment_.main_part_)
  79     {
  80       stop_fall ();
  81     }
  82 }
  83
  84 void
  85 Bend_engraver::acknowledge_note_head (Grob_info info)
  86 {
  87   if (!fall_event_)
  88     return;
  89
  90   if (note_head_ && fall_)
  91     {
  92       stop_fall ();
  93     }
  94
  95   note_head_ = info.grob ();
  96   stop_moment_ = now_mom () + get_event_length (info.event_cause (),
  97                                                 now_mom ());
  98 }
  99
 100 Bend_engraver::Bend_engraver ()
 101 {
 102   fall_ = 0;
 103   last_fall_ = 0;
 104   note_head_ = 0;
 105   fall_event_ = 0;
 106 }
 107
 108 IMPLEMENT_TRANSLATOR_LISTENER (Bend_engraver, bend_after);
 109 void
 110 Bend_engraver::listen_bend_after (Stream_event *ev)
 111 {
 112   ASSIGN_EVENT_ONCE (fall_event_, ev);
 113 }
 114
 115 void
 116 Bend_engraver::process_music ()
 117 {
 118   if (fall_event_ && !fall_)
 119     {
 120       fall_ = make_spanner ("BendAfter", fall_event_->self_scm ());
 121       fall_->set_property ("delta-position",
 122                            scm_from_double (robust_scm2double (fall_event_->get_property ("delta-step"), 0)));
 123     }
 124 }
 125
 126 ADD_ACKNOWLEDGER (Bend_engraver, note_head);
 127
 128 ADD_TRANSLATOR (Bend_engraver,
 129                 /* doc */
 130                 "Create fall spanners.",
 131
 132                 /* create */
 133                 "BendAfter ",
 134
 135                 /* read */
 136                 "",
 137
 138                 /* write */
 139                 ""
 140                 );