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--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "separating-group-spanner.hh"
  10 #include "separation-item.hh"
  11 #include "paper-column.hh"
  12 #include "output-def.hh"
  13 #include "engraver.hh"
  14 #include "axis-group-interface.hh"
  15 #include "note-spacing.hh"
  16 #include "accidental-placement.hh"
  17 #include "context.hh"
  18 #include "grob-array.hh"
  19
  20 struct Spacings
  21 {
  22   Item *staff_spacing_;
  23   Link_array<Item> note_spacings_;
  24
  25   Spacings ()
  26   {
  27     staff_spacing_ = 0;
  28   }
  29
  30   bool is_empty () const
  31   {
  32     return !staff_spacing_ && !note_spacings_.size ();
  33   }
  34   void clear ()
  35   {
  36     staff_spacing_ = 0;
  37     note_spacings_.clear ();
  38   }
  39 };
  40
  41 class Separating_line_group_engraver : public Engraver
  42 {
  43 protected:
  44   Item *break_item_;
  45   Item *musical_item_;
  46   Item *last_musical_item_;
  47
  48   Spacings current_spacings_;
  49   Spacings last_spacings_;
  50
  51   Spanner *sep_span_;
  52
  53   virtual void acknowledge_grob (Grob_info);
  54   virtual void process_music ();
  55   virtual void finalize ();
  56   virtual void stop_translation_timestep ();
  57   virtual void start_translation_timestep ();
  58 public:
  59   TRANSLATOR_DECLARATIONS (Separating_line_group_engraver);
  60 };
  61
  62 Separating_line_group_engraver::Separating_line_group_engraver ()
  63 {
  64   sep_span_ = 0;
  65   break_item_ = 0;
  66   musical_item_ = 0;
  67 }
  68
  69 void
  70 Separating_line_group_engraver::process_music ()
  71 {
  72
  73   if (!sep_span_)
  74     {
  75       sep_span_ = make_spanner ("SeparatingGroupSpanner", SCM_EOL);
  76
  77       sep_span_->set_bound (LEFT, unsmob_grob (get_property ("currentCommandColumn")));
  78     }
  79 }
  80 void
  81 Separating_line_group_engraver::finalize ()
  82 {
  83   if (!sep_span_)
  84     return;
  85
  86   SCM ccol = get_property ("currentCommandColumn");
  87   Grob *column = unsmob_grob (ccol);
  88
  89   sep_span_->set_bound (RIGHT, unsmob_grob (ccol));
  90   sep_span_ = 0;
  91
  92   for (int i = 0; i < last_spacings_.note_spacings_.size (); i++)
  93     {
  94       Pointer_group_interface::add_grob (last_spacings_.note_spacings_[i],
  95                                          ly_symbol2scm ("right-items"),
  96                                          column);
  97     }
  98
  99   if (last_spacings_.staff_spacing_
 100       && last_spacings_.staff_spacing_->get_column () == column)
 101     {
 102       last_spacings_.staff_spacing_->suicide ();
 103     }
 104 }
 105
 106 void
 107 Separating_line_group_engraver::acknowledge_grob (Grob_info i)
 108 {
 109   Item *it = dynamic_cast<Item *> (i.grob ());
 110   if (!it)
 111     return;
 112   if (it->get_parent (X_AXIS)
 113       && it->get_parent (X_AXIS)
 114       ->has_extent_callback (Axis_group_interface::group_extent_callback_proc, X_AXIS))
 115     return;
 116
 117   if (to_boolean (it->get_property ("no-spacing-rods")))
 118     return;
 119
 120   if (Note_spacing::has_interface (it))
 121     {
 122       current_spacings_.note_spacings_.push (it);
 123       return;
 124     }
 125
 126   bool ib = Item::is_breakable (it);
 127   Item *&p_ref_ (ib ? break_item_
 128                  : musical_item_);
 129
 130   if (!p_ref_)
 131     {
 132       p_ref_ = make_item ("SeparationItem", SCM_EOL);
 133
 134       if (ib)
 135         {
 136           p_ref_->set_property ("breakable", SCM_BOOL_T);
 137           context ()->set_property ("breakableSeparationItem", p_ref_->self_scm ());
 138         }
 139
 140       if (to_boolean (get_property ("createSpacing"))
 141           && p_ref_ == break_item_)
 142         {
 143           Item *it = make_item ("StaffSpacing", SCM_EOL);
 144           current_spacings_.staff_spacing_ = it;
 145           Pointer_group_interface::add_grob (it,  ly_symbol2scm ("left-items"),
 146                                              break_item_);
 147
 148           if (int i = last_spacings_.note_spacings_.size ())
 149             {
 150               for (; i--;)
 151                 Pointer_group_interface::add_grob (last_spacings_.note_spacings_[i],
 152                                                    ly_symbol2scm ("right-items"),
 153                                                    break_item_);
 154             }
 155           else if (last_spacings_.staff_spacing_)
 156             {
 157               SCM ri = last_spacings_.staff_spacing_->get_object ("right-items");
 158               Grob_array *ga  = unsmob_grob_array (ri);
 159               if (!ga)
 160                 {
 161                   SCM ga_scm = Grob_array::make_array ();
 162                   last_spacings_.staff_spacing_->set_object ("right-items", ga_scm);
 163                   ga = unsmob_grob_array (ga_scm);
 164                 }
 165
 166               ga->clear ();
 167               ga->add (break_item_);
 168             }
 169         }
 170     }
 171
 172   if (Accidental_placement::has_interface (it))
 173     Separation_item::add_conditional_item (p_ref_, it);
 174   else
 175     Separation_item::add_item (p_ref_, it);
 176 }
 177
 178 void
 179 Separating_line_group_engraver::start_translation_timestep ()
 180 {
 181   if (break_item_)
 182     context ()->unset_property (ly_symbol2scm ("breakableSeparationItem"));
 183   break_item_ = 0;
 184 }
 185
 186 void
 187 Separating_line_group_engraver::stop_translation_timestep ()
 188 {
 189   if (break_item_)
 190     {
 191       Separating_group_spanner::add_spacing_unit (sep_span_, break_item_);
 192     }
 193
 194   if (Item *sp = current_spacings_.staff_spacing_)
 195     {
 196       /*
 197         TODO: should really look at the left-items of following
 198         note-spacing grobs.
 199       */
 200       if (musical_item_)
 201         Pointer_group_interface::add_grob (sp, ly_symbol2scm ("right-items"),
 202                                            musical_item_);
 203     }
 204
 205   if (!current_spacings_.is_empty ())
 206     {
 207       last_spacings_ = current_spacings_;
 208     }
 209
 210   current_spacings_.clear ();
 211
 212   if (musical_item_)
 213     {
 214       Separating_group_spanner::add_spacing_unit (sep_span_, musical_item_);
 215     }
 216
 217   musical_item_ = 0;
 218 }
 219
 220 ADD_TRANSLATOR (Separating_line_group_engraver,
 221                 /* descr */ "Generates objects for computing spacing parameters.",
 222                 /* creats*/ "SeparationItem SeparatingGroupSpanner StaffSpacing",
 223                 /* accepts */ "",
 224                 /* acks  */ "item-interface",
 225                 /* reads */ "createSpacing",
 226                 /* write */ "breakableSeparationItem");