lily/collision-engraver.cc

   1 /*
   2   collision-reg.cc -- implement Collision_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "note-column.hh"
  10 #include "note-collision.hh"
  11
  12 #include "engraver.hh"
  13 #include "axis-group-interface.hh"
  14
  15 /*
  16   collect Note_column, and as soon as there are 2 or more, put them in
  17   a collision object.  */
  18 class Collision_engraver : public Engraver {
  19   Item * col_;
  20   Link_array<Grob> note_columns_;
  21
  22 protected:
  23   virtual void acknowledge_grob (Grob_info);
  24   virtual void process_acknowledged_grobs ();
  25   virtual void stop_translation_timestep ();
  26 public:
  27   TRANSLATOR_DECLARATIONS(Collision_engraver);
  28 };
  29
  30
  31 void
  32 Collision_engraver::process_acknowledged_grobs ()
  33 {
  34   if (col_ || note_columns_.size () < 2)
  35     return ;
  36   if (!col_)
  37     {
  38       col_ = new Item (get_property ("NoteCollision"));
  39       announce_grob (col_, SCM_EOL);
  40     }
  41
  42   for (int i=0; i< note_columns_.size (); i++)
  43     Note_collision_interface::add_column (col_,note_columns_[i]);
  44 }
  45
  46 void
  47 Collision_engraver::acknowledge_grob (Grob_info i)
  48 {
  49   if (Note_column::has_interface (i.grob_))
  50     {
  51       /*should check Y axis? */
  52       if (Note_column::rest_b (i.grob_) || i.grob_->get_parent (X_AXIS))
  53         return ;
  54
  55       note_columns_.push (i.grob_);
  56     }
  57 }
  58
  59 void
  60 Collision_engraver::stop_translation_timestep ()
  61 {
  62   if (col_)
  63     {
  64       typeset_grob (col_);
  65       col_ =0;
  66     }
  67   note_columns_.clear ();
  68 }
  69
  70 Collision_engraver::Collision_engraver ()
  71 {
  72   col_ =0;
  73 }
  74
  75
  76
  77
  78 ENTER_DESCRIPTION(Collision_engraver,
  79 /* descr */       "",
  80 /* creats*/       "NoteCollision",
  81 /* accepts */     "",
  82 /* acks  */      "note-column-interface",
  83 /* reads */       "",
  84 /* write */       "");