lily/separating-line-group-engraver.cc

   1 /*
   2   separating-line-group-engraver.cc -- implement Separating_line_group_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1998--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "engraver.hh"
  10
  11 #include "separation-item.hh"
  12 #include "paper-column.hh"
  13 #include "output-def.hh"
  14 #include "axis-group-interface.hh"
  15 #include "note-spacing.hh"
  16 #include "accidental-placement.hh"
  17 #include "context.hh"
  18 #include "spanner.hh"
  19 #include "grob-array.hh"
  20 #include "pointer-group-interface.hh"
  21
  22 #include "translator.icc"
  23
  24 struct Spacings
  25 {
  26   Item *staff_spacing_;
  27   vector<Item*> note_spacings_;
  28
  29   Spacings ()
  30   {
  31     staff_spacing_ = 0;
  32   }
  33
  34   bool is_empty () const
  35   {
  36     return !staff_spacing_ && !note_spacings_.size ();
  37   }
  38   void clear ()
  39   {
  40     staff_spacing_ = 0;
  41     note_spacings_.clear ();
  42   }
  43 };
  44
  45 class Separating_line_group_engraver : public Engraver
  46 {
  47 protected:
  48   Spacings current_spacings_;
  49   Spacings last_spacings_;
  50
  51   DECLARE_ACKNOWLEDGER (item);
  52   void stop_translation_timestep ();
  53   void start_translation_timestep ();
  54 public:
  55   TRANSLATOR_DECLARATIONS (Separating_line_group_engraver);
  56 };
  57
  58 Separating_line_group_engraver::Separating_line_group_engraver ()
  59 {
  60 }
  61
  62 void
  63 Separating_line_group_engraver::acknowledge_item (Grob_info i)
  64 {
  65   Item *it = i.item ();
  66
  67   if (Note_spacing::has_interface (it))
  68     {
  69       current_spacings_.note_spacings_.push_back (it);
  70       return;
  71     }
  72
  73   if (Item::is_non_musical (it)
  74       && !current_spacings_.staff_spacing_
  75       && to_boolean (get_property ("createSpacing")))
  76     {
  77       Grob *col = unsmob_grob (get_property ("currentCommandColumn"));
  78
  79       current_spacings_.staff_spacing_ = make_item ("StaffSpacing", SCM_EOL);
  80       context ()->set_property ("hasStaffSpacing", SCM_BOOL_T);
  81
  82       Pointer_group_interface::add_grob (current_spacings_.staff_spacing_,
  83                                          ly_symbol2scm ("left-items"),
  84                                          col);
  85
  86       if (!last_spacings_.note_spacings_.size ()
  87           && last_spacings_.staff_spacing_)
  88         {
  89           SCM ri = last_spacings_.staff_spacing_->get_object ("right-items");
  90           Grob_array *ga = unsmob_grob_array (ri);
  91           if (!ga)
  92             {
  93               SCM ga_scm = Grob_array::make_array ();
  94               last_spacings_.staff_spacing_->set_object ("right-items", ga_scm);
  95               ga = unsmob_grob_array (ga_scm);
  96             }
  97
  98           ga->clear ();
  99           ga->add (col);
 100         }
 101     }
 102 }
 103
 104 void
 105 Separating_line_group_engraver::start_translation_timestep ()
 106 {
 107   context ()->unset_property (ly_symbol2scm ("hasStaffSpacing"));
 108 }
 109
 110 void
 111 Separating_line_group_engraver::stop_translation_timestep ()
 112 {
 113   if (!current_spacings_.is_empty ())
 114     last_spacings_ = current_spacings_;
 115
 116   if (Item *sp = current_spacings_.staff_spacing_)
 117     if (Grob *col = unsmob_grob (get_property ("currentMusicalColumn")))
 118       Pointer_group_interface::add_grob (sp, ly_symbol2scm ("right-items"), col);
 119
 120   current_spacings_.clear ();
 121 }
 122
 123 ADD_ACKNOWLEDGER (Separating_line_group_engraver, item);
 124 ADD_TRANSLATOR (Separating_line_group_engraver,
 125                 /* doc */ "Generates objects for computing spacing parameters.",
 126
 127                 /* create */ "StaffSpacing",
 128                 /* read */ "createSpacing",
 129                 /* write */ "hasStaffSpacing"
 130                 );