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
  10 #include "separating-group-spanner.hh"
  11 #include "separation-item.hh"
  12 #include "paper-column.hh"
  13 #include "output-def.hh"
  14 #include "engraver.hh"
  15 #include "axis-group-interface.hh"
  16 #include "note-spacing.hh"
  17 #include "accidental-placement.hh"
  18 #include "context.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     staff_spacing_ = 0;
  36     note_spacings_.clear ();
  37   }
  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
  78       sep_span_->set_bound (LEFT, unsmob_grob (get_property ("currentCommandColumn")));
  79     }
  80 }
  81 void
  82 Separating_line_group_engraver::finalize ()
  83 {
  84   if (!sep_span_)
  85     return ;
  86
  87   SCM ccol = get_property ("currentCommandColumn");
  88   Grob *column = unsmob_grob (ccol);
  89
  90   sep_span_->set_bound (RIGHT, unsmob_grob (ccol));
  91   sep_span_ = 0;
  92
  93   for  (int i = 0 ; i < last_spacings_.note_spacings_.size (); i++)
  94     {
  95       Pointer_group_interface::add_grob (last_spacings_.note_spacings_[i],
  96                                          ly_symbol2scm ("right-items" ),
  97                                          column);
  98     }
  99
 100   if (last_spacings_.staff_spacing_
 101      && last_spacings_.staff_spacing_->get_column () == column)
 102     {
 103       last_spacings_.staff_spacing_->suicide ();
 104     }
 105 }
 106
 107 void
 108 Separating_line_group_engraver::acknowledge_grob (Grob_info i)
 109 {
 110   Item * it = dynamic_cast <Item *> (i.grob_);
 111   if (!it)
 112     return;
 113   if (it->get_parent (X_AXIS)
 114       && it->get_parent (X_AXIS)
 115       ->has_extent_callback (Axis_group_interface::group_extent_callback_proc, X_AXIS))
 116     return;
 117
 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
 143       if (to_boolean (get_property ("createSpacing"))
 144           && p_ref_ == break_item_)
 145         {
 146           Item *it  = make_item ("StaffSpacing", SCM_EOL);
 147           current_spacings_.staff_spacing_ = it;
 148           it->set_property ("left-items", scm_cons (break_item_->self_scm (), SCM_EOL));
 149
 150
 151
 152           if (int i = last_spacings_.note_spacings_.size ())
 153             {
 154               for (; i--;)
 155                 Pointer_group_interface::add_grob (last_spacings_.note_spacings_[i],
 156                                                    ly_symbol2scm ("right-items"),
 157                                                    break_item_);
 158
 159             }
 160           else if (last_spacings_.staff_spacing_)
 161             {
 162               last_spacings_.staff_spacing_->set_property ("right-items",
 163                                                                 scm_cons (break_item_->self_scm (), SCM_EOL));
 164             }
 165         }
 166     }
 167
 168   if (Accidental_placement::has_interface (it))
 169     Separation_item::add_conditional_item (p_ref_, it);
 170   else
 171     Separation_item::add_item (p_ref_, it);
 172 }
 173
 174 void
 175 Separating_line_group_engraver::start_translation_timestep ()
 176 {
 177   if (break_item_)
 178     context ()->unset_property (ly_symbol2scm ("breakableSeparationItem"));
 179   break_item_ = 0;
 180 }
 181
 182 void
 183 Separating_line_group_engraver::stop_translation_timestep ()
 184 {
 185   if (break_item_)
 186     {
 187       Separating_group_spanner::add_spacing_unit (sep_span_, break_item_);
 188     }
 189
 190   if (Item * sp = current_spacings_.staff_spacing_)
 191     {
 192       /*
 193         TODO: should really look at the left-items of following
 194         note-spacing grobs.
 195        */
 196       if (musical_item_)
 197         Pointer_group_interface::add_grob (sp, ly_symbol2scm ("right-items"),
 198                                            musical_item_);
 199
 200     }
 201
 202
 203   if (!current_spacings_.is_empty ())
 204     {
 205       last_spacings_ = current_spacings_;
 206     }
 207
 208   current_spacings_.clear ();
 209
 210   if (musical_item_)
 211     {
 212       Separating_group_spanner::add_spacing_unit (sep_span_, musical_item_);
 213     }
 214
 215   musical_item_ = 0;
 216 }
 217
 218
 219 ADD_TRANSLATOR (Separating_line_group_engraver,
 220 /* descr */       "Generates objects for computing spacing parameters.",
 221 /* creats*/       "SeparationItem SeparatingGroupSpanner StaffSpacing",
 222 /* accepts */     "",
 223 /* acks  */      "item-interface",
 224 /* reads */       "createSpacing",
 225 /* write */       "breakableSeparationItem");