lily/grace-position-engraver.cc

   1 /*
   2   grace-position-engraver.cc --  implement Grace_position_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1999--2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "engraver.hh"
  11 #include "grace-align-item.hh"
  12 #include "rhythmic-head.hh"
  13 #include "local-key-item.hh"
  14 #include "paper-column.hh"
  15 #include "note-head.hh"
  16 #include "side-position-interface.hh"
  17 #include "axis-group-interface.hh"
  18
  19
  20 class Grace_position_engraver:public Engraver
  21 {
  22   Paper_column *last_musical_col_l_;
  23 protected:
  24   VIRTUAL_COPY_CONS (Translator);
  25   virtual void acknowledge_grob (Grob_info);
  26   virtual void create_grobs ();
  27   virtual void start_translation_timestep ();
  28   virtual void stop_translation_timestep ();
  29   Item*align_l_;
  30   Link_array<Item> support_;
  31 public:
  32   Grace_position_engraver ();
  33 };
  34
  35
  36 Grace_position_engraver::Grace_position_engraver ()
  37 {
  38   align_l_ =0;
  39   last_musical_col_l_ =0;
  40 }
  41
  42 void
  43 Grace_position_engraver::acknowledge_grob (Grob_info i)
  44 {
  45   Item *item = dynamic_cast<Item*> (i.elem_l_);
  46   if (item && Grace_align_item::has_interface (i.elem_l_))
  47     {
  48       align_l_ = item;
  49     }
  50   else if (item && Note_head::has_interface (i.elem_l_))
  51     {
  52       if (!to_boolean (item->get_grob_property ("grace")))
  53         support_.push (item);
  54     }
  55   else if (item && Local_key_item::has_interface (i.elem_l_))
  56     {
  57       if (!to_boolean (item->get_grob_property ("grace")))
  58         support_.push (item);
  59       else if (align_l_)
  60         item->add_dependency (align_l_);
  61     }
  62 }
  63
  64 void
  65 Grace_position_engraver::create_grobs ()
  66 {
  67   if (align_l_)
  68     {
  69       for (int i=0; i < support_.size (); i++)
  70         Side_position_interface::add_support (align_l_,support_[i]);
  71       support_.clear ();
  72     }
  73 }
  74
  75 void
  76 Grace_position_engraver::stop_translation_timestep ()
  77 {
  78   if (align_l_ && !Side_position_interface::supported_b (align_l_))
  79     {
  80   /*
  81      We don't have support. Either some moron tried attaching us to a rest,
  82      or we're at the end of the piece.  In the latter case, we have a
  83      problem if there are spanners in the grace section,
  84      they will want to  be broken into pieces (their line_l () field  is nil).
  85
  86      Solution: attach ourselves to  the last musical column known.  A little intricate.
  87
  88   */
  89
  90       Grob * elt = align_l_->parent_l (X_AXIS);
  91       if (elt)
  92         return;
  93
  94       if (last_musical_col_l_)
  95         {
  96           warning (_ ("Unattached grace notes.  Attaching to last musical column."));
  97
  98           align_l_->set_parent (0, X_AXIS);
  99           Axis_group_interface::add_element (last_musical_col_l_, align_l_);
 100         }
 101       else
 102         {
 103           // tja.
 104         }
 105     }
 106   last_musical_col_l_ = dynamic_cast<Paper_column*> (unsmob_grob (get_property ("currentMusicalColumn")));
 107 }
 108
 109 void
 110 Grace_position_engraver::start_translation_timestep ()
 111 {
 112   support_.clear ();
 113   align_l_ =0;
 114 }
 115
 116 ADD_THIS_TRANSLATOR (Grace_position_engraver);
 117