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--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "separating-group-spanner.hh"
  11 #include "separation-item.hh"
  12 #include "paper-column.hh"
  13 #include "paper-def.hh"
  14 #include "engraver.hh"
  15 #include "axis-group-interface.hh"
  16 #include "note-spacing.hh"
  17 #include "group-interface.hh"
  18 #include "accidental-placement.hh"
  19 #include "context.hh"
  20
  21
  22
  23 struct Spacings
  24 {
  25   Item * staff_spacing_;
  26   Link_array<Item> note_spacings_;
  27
  28   Spacings ()
  29   {
  30     staff_spacing_ = 0;
  31   }
  32
  33   bool is_empty () const
  34   {
  35     return !staff_spacing_ && !note_spacings_.size ();
  36   }
  37   void clear () {
  38     staff_spacing_ = 0;
  39     note_spacings_.clear ();
  40   }
  41 };
  42
  43
  44 class Separating_line_group_engraver : public Engraver
  45 {
  46 protected:
  47   Item * break_item_;
  48   Item * musical_item_;
  49   Item * last_musical_item_;
  50
  51   Spacings current_spacings_;
  52   Spacings last_spacings_;
  53
  54   Spanner * sep_span_;
  55
  56   virtual void acknowledge_grob (Grob_info);
  57   virtual void process_music ();
  58   virtual void finalize ();
  59   virtual void stop_translation_timestep ();
  60   virtual void start_translation_timestep ();
  61 public:
  62   TRANSLATOR_DECLARATIONS (Separating_line_group_engraver);
  63 };
  64
  65 Separating_line_group_engraver::Separating_line_group_engraver ()
  66 {
  67   sep_span_ = 0;
  68   break_item_ = 0;
  69   musical_item_ =0;
  70 }
  71
  72 void
  73 Separating_line_group_engraver::process_music ()
  74 {
  75
  76   if (!sep_span_)
  77     {
  78       sep_span_ = make_spanner ("SeparatingGroupSpanner", SCM_EOL);
  79
  80
  81       sep_span_->set_bound (LEFT, unsmob_grob (get_property ("currentCommandColumn")));
  82     }
  83 }
  84 void
  85 Separating_line_group_engraver::finalize ()
  86 {
  87   if (!sep_span_)
  88     return ;
  89
  90   SCM ccol = get_property ("currentCommandColumn");
  91   Grob *column = unsmob_grob (ccol);
  92
  93   sep_span_->set_bound (RIGHT, unsmob_grob (ccol));
  94   sep_span_ =0;
  95
  96   for  (int i= 0 ; i < last_spacings_.note_spacings_.size (); i++)
  97     {
  98       Pointer_group_interface::add_grob (last_spacings_.note_spacings_[i],
  99                                          ly_symbol2scm ("right-items" ),
 100                                          column);
 101     }
 102
 103   if (last_spacings_.staff_spacing_
 104      && last_spacings_.staff_spacing_->get_column () == column)
 105     {
 106       last_spacings_.staff_spacing_->suicide ();
 107     }
 108 }
 109
 110 void
 111 Separating_line_group_engraver::acknowledge_grob (Grob_info i)
 112 {
 113   Item * it = dynamic_cast <Item *> (i.grob_);
 114   if (!it)
 115     return;
 116   if (it->get_parent (X_AXIS)
 117       && it->get_parent (X_AXIS)
 118       ->has_extent_callback (Axis_group_interface::group_extent_callback_proc, X_AXIS))
 119     return;
 120
 121
 122   if (to_boolean (it->get_property ("no-spacing-rods")))
 123     return ;
 124
 125   if (Note_spacing::has_interface (it))
 126     {
 127       current_spacings_.note_spacings_.push (it);
 128       return ;
 129     }
 130
 131   bool ib =Item::is_breakable (it);
 132   Item *&p_ref_ (ib ? break_item_
 133                  : musical_item_);
 134
 135   if (!p_ref_)
 136     {
 137       p_ref_ = make_item ("SeparationItem", SCM_EOL);
 138
 139       if (ib)
 140         {
 141           p_ref_->set_property ("breakable", SCM_BOOL_T);
 142           context ()->set_property ("breakableSeparationItem", p_ref_->self_scm ());
 143         }
 144
 145
 146       if (to_boolean (get_property ("createSpacing"))
 147           && p_ref_ == break_item_)
 148         {
 149           Item *it  = make_item ("StaffSpacing", SCM_EOL);
 150           current_spacings_.staff_spacing_ = it;
 151           it->set_property ("left-items", scm_cons (break_item_->self_scm (), SCM_EOL));
 152
 153
 154
 155           if (int i = last_spacings_.note_spacings_.size ())
 156             {
 157               for (; i--;)
 158                 Pointer_group_interface::add_grob (last_spacings_.note_spacings_[i],
 159                                                    ly_symbol2scm ("right-items"),
 160                                                    break_item_);
 161
 162             }
 163           else if (last_spacings_.staff_spacing_)
 164             {
 165               last_spacings_.staff_spacing_->set_property ("right-items",
 166                                                                 scm_cons (break_item_->self_scm (), SCM_EOL));
 167             }
 168         }
 169     }
 170
 171   if (Accidental_placement::has_interface (it))
 172     Separation_item::add_conditional_item (p_ref_, it);
 173   else
 174     Separation_item::add_item (p_ref_,it);
 175 }
 176
 177 void
 178 Separating_line_group_engraver::start_translation_timestep ()
 179 {
 180   if (break_item_)
 181     context ()->unset_property (ly_symbol2scm ("breakableSeparationItem"));
 182   break_item_ =0;
 183 }
 184
 185 void
 186 Separating_line_group_engraver::stop_translation_timestep ()
 187 {
 188   if (break_item_)
 189     {
 190       Separating_group_spanner::add_spacing_unit (sep_span_, break_item_);
 191     }
 192
 193   if (Item * sp = current_spacings_.staff_spacing_)
 194     {
 195       /*
 196         TODO: should really look at the left-items of following
 197         note-spacing grobs.
 198        */
 199       if (musical_item_)
 200         Pointer_group_interface::add_grob (sp, ly_symbol2scm ("right-items"),
 201                                            musical_item_);
 202
 203     }
 204
 205
 206   if (!current_spacings_.is_empty ())
 207     {
 208       last_spacings_ = current_spacings_;
 209     }
 210
 211   current_spacings_.clear ();
 212
 213   if (musical_item_)
 214     {
 215       Separating_group_spanner::add_spacing_unit (sep_span_, musical_item_);
 216     }
 217
 218   musical_item_ =0;
 219 }
 220
 221
 222 ENTER_DESCRIPTION (Separating_line_group_engraver,
 223 /* descr */       "Generates objects for computing spacing parameters.",
 224 /* creats*/       "SeparationItem SeparatingGroupSpanner StaffSpacing",
 225 /* accepts */     "",
 226 /* acks  */      "item-interface",
 227 /* reads */       "createSpacing",
 228 /* write */       "breakableSeparationItem");