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 #include "translator.icc"
  23
  24 struct Spacings
  25 {
  26   Item *staff_spacing_;
  27   Link_array<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   Item *break_item_;
  49   Item *musical_item_;
  50   Item *last_musical_item_;
  51
  52   Spacings current_spacings_;
  53   Spacings last_spacings_;
  54
  55   Spanner *sep_span_;
  56
  57   DECLARE_ACKNOWLEDGER(item);
  58   PRECOMPUTED_VIRTUAL void process_music ();
  59   virtual void finalize ();
  60   PRECOMPUTED_VIRTUAL void stop_translation_timestep ();
  61   PRECOMPUTED_VIRTUAL void start_translation_timestep ();
  62 public:
  63   TRANSLATOR_DECLARATIONS (Separating_line_group_engraver);
  64 };
  65
  66 Separating_line_group_engraver::Separating_line_group_engraver ()
  67 {
  68   sep_span_ = 0;
  69   break_item_ = 0;
  70   musical_item_ = 0;
  71 }
  72
  73 void
  74 Separating_line_group_engraver::process_music ()
  75 {
  76
  77   if (!sep_span_)
  78     {
  79       sep_span_ = make_spanner ("SeparatingGroupSpanner", SCM_EOL);
  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_item (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   if (to_boolean (it->get_property ("no-spacing-rods")))
 122     return;
 123
 124   if (Note_spacing::has_interface (it))
 125     {
 126       current_spacings_.note_spacings_.push (it);
 127       return;
 128     }
 129
 130   bool ib = Item::is_breakable (it);
 131   Item *&p_ref_ (ib ? break_item_
 132                  : musical_item_);
 133
 134   if (!p_ref_)
 135     {
 136       p_ref_ = make_item ("SeparationItem", SCM_EOL);
 137
 138       if (ib)
 139         {
 140           p_ref_->set_property ("breakable", SCM_BOOL_T);
 141           context ()->set_property ("breakableSeparationItem", p_ref_->self_scm ());
 142         }
 143
 144       if (to_boolean (get_property ("createSpacing"))
 145           && p_ref_ == break_item_)
 146         {
 147           Item *it = make_item ("StaffSpacing", SCM_EOL);
 148           current_spacings_.staff_spacing_ = it;
 149           Pointer_group_interface::add_grob (it,  ly_symbol2scm ("left-items"),
 150                                              break_item_);
 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           else if (last_spacings_.staff_spacing_)
 160             {
 161               SCM ri = last_spacings_.staff_spacing_->get_object ("right-items");
 162               Grob_array *ga  = unsmob_grob_array (ri);
 163               if (!ga)
 164                 {
 165                   SCM ga_scm = Grob_array::make_array ();
 166                   last_spacings_.staff_spacing_->set_object ("right-items", ga_scm);
 167                   ga = unsmob_grob_array (ga_scm);
 168                 }
 169
 170               ga->clear ();
 171               ga->add (break_item_);
 172             }
 173         }
 174     }
 175
 176   if (Accidental_placement::has_interface (it))
 177     Separation_item::add_conditional_item (p_ref_, it);
 178   else
 179     Separation_item::add_item (p_ref_, it);
 180 }
 181
 182 void
 183 Separating_line_group_engraver::start_translation_timestep ()
 184 {
 185   if (break_item_)
 186     {
 187       context ()->unset_property (ly_symbol2scm ("breakableSeparationItem"));
 188       break_item_ = 0;
 189     }
 190 }
 191
 192 void
 193 Separating_line_group_engraver::stop_translation_timestep ()
 194 {
 195   if (break_item_)
 196     {
 197       Separating_group_spanner::add_spacing_unit (sep_span_, break_item_);
 198     }
 199
 200   if (Item *sp = current_spacings_.staff_spacing_)
 201     {
 202       /*
 203         TODO: should really look at the left-items of following
 204         note-spacing grobs.
 205       */
 206       if (musical_item_)
 207         Pointer_group_interface::add_grob (sp, ly_symbol2scm ("right-items"),
 208                                            musical_item_);
 209     }
 210
 211   if (!current_spacings_.is_empty ())
 212     {
 213       last_spacings_ = current_spacings_;
 214     }
 215
 216   current_spacings_.clear ();
 217
 218   if (musical_item_)
 219     {
 220       Separating_group_spanner::add_spacing_unit (sep_span_, musical_item_);
 221     }
 222
 223   musical_item_ = 0;
 224 }
 225
 226 ADD_ACKNOWLEDGER(Separating_line_group_engraver, item);
 227 ADD_TRANSLATOR (Separating_line_group_engraver,
 228                 /* descr */ "Generates objects for computing spacing parameters.",
 229                 /* creats*/ "SeparationItem SeparatingGroupSpanner StaffSpacing",
 230                 /* accepts */ "",
 231                 /* reads */ "createSpacing",
 232                 /* write */ "breakableSeparationItem");