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