lily/bend-engraver.cc

   1 /*
   2   bend-engraver.cc -- implement Bend_engraver
   3
   4   (c) 2006--2007 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 process_music ();
  26   void stop_translation_timestep ();
  27   void start_translation_timestep ();
  28   void stop_fall ();
  29
  30 private:
  31   Moment stop_moment_;
  32   Stream_event *fall_event_;
  33   Spanner *fall_;
  34   Grob *note_head_;
  35 };
  36
  37 void
  38 Bend_engraver::stop_fall ()
  39 {
  40   bool bar = scm_is_string (get_property ("whichBar"));
  41
  42
  43   fall_->set_bound (RIGHT, unsmob_grob (bar
  44                                         ? get_property ("currentCommandColumn")
  45                                         : get_property ("currentMusicalColumn")));
  46   fall_ = 0;
  47   note_head_ = 0;
  48   fall_event_ = 0;
  49 }
  50
  51 void
  52 Bend_engraver::stop_translation_timestep ()
  53 {
  54   if (fall_ && !fall_->get_bound (LEFT))
  55     {
  56       fall_->set_bound (LEFT, note_head_);
  57       fall_->set_parent (note_head_,  Y_AXIS);
  58     }
  59 }
  60
  61 void
  62 Bend_engraver::start_translation_timestep ()
  63 {
  64   if (fall_ && now_mom ().main_part_ >= stop_moment_.main_part_)
  65     {
  66       stop_fall ();
  67     }
  68 }
  69
  70 void
  71 Bend_engraver::acknowledge_note_head (Grob_info info)
  72 {
  73   if (!fall_event_)
  74     return;
  75
  76   if (note_head_ && fall_)
  77     {
  78       stop_fall ();
  79     }
  80
  81   note_head_ = info.grob ();
  82   stop_moment_ = now_mom () + get_event_length (info.event_cause (),
  83                                                 now_mom ());
  84 }
  85
  86 Bend_engraver::Bend_engraver ()
  87 {
  88   fall_ = 0;
  89   note_head_ = 0;
  90   fall_event_ = 0;
  91 }
  92
  93 IMPLEMENT_TRANSLATOR_LISTENER (Bend_engraver, bend_after);
  94 void
  95 Bend_engraver::listen_bend_after (Stream_event *ev)
  96 {
  97   ASSIGN_EVENT_ONCE (fall_event_, ev);
  98 }
  99
 100 void
 101 Bend_engraver::process_music ()
 102 {
 103   if (fall_event_ && !fall_)
 104     {
 105       fall_ = make_spanner ("BendAfter", fall_event_->self_scm ());
 106       fall_->set_property ("delta-position",
 107                            scm_from_double (robust_scm2double (fall_event_->get_property ("delta-step"), 0)));
 108     }
 109 }
 110
 111 ADD_ACKNOWLEDGER (Bend_engraver, note_head);
 112
 113 ADD_TRANSLATOR (Bend_engraver,
 114                 /* doc */
 115                 "Create fall spanners.",
 116
 117                 /* create */
 118                 "BendAfter ",
 119
 120                 /* read */
 121                 "",
 122
 123                 /* write */
 124                 ""
 125                 );