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