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--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "engraver.hh"
  10
  11 #include "separation-item.hh"
  12 #include "paper-column.hh"
  13 #include "output-def.hh"
  14 #include "axis-group-interface.hh"
  15 #include "note-spacing.hh"
  16 #include "accidental-placement.hh"
  17 #include "context.hh"
  18 #include "spanner.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   vector<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   DECLARE_ACKNOWLEDGER (item);
  56   void stop_translation_timestep ();
  57   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   break_item_ = 0;
  65   musical_item_ = 0;
  66 }
  67
  68 void
  69 Separating_line_group_engraver::acknowledge_item (Grob_info i)
  70 {
  71   Item *it = i.item ();
  72   if (it->get_parent (X_AXIS)
  73       && it->get_parent (X_AXIS) == it->get_parent (Y_AXIS)
  74       && Axis_group_interface::has_axis (it->get_parent (X_AXIS), X_AXIS)
  75       && Axis_group_interface::has_axis (it->get_parent (Y_AXIS), Y_AXIS))
  76     return;
  77
  78   if (to_boolean (it->get_property ("no-spacing-rods")))
  79     return;
  80
  81   if (Note_spacing::has_interface (it))
  82     {
  83       current_spacings_.note_spacings_.push_back (it);
  84       return;
  85     }
  86
  87   bool ib = Item::is_non_musical (it);
  88   Item *&p_ref_ (ib ? break_item_
  89                  : musical_item_);
  90
  91   if (!p_ref_)
  92     {
  93       p_ref_ = make_item ("SeparationItem", SCM_EOL);
  94
  95       if (ib)
  96         {
  97           p_ref_->set_property ("non-musical", SCM_BOOL_T);
  98           context ()->set_property ("breakableSeparationItem", p_ref_->self_scm ());
  99         }
 100
 101       if (to_boolean (get_property ("createSpacing"))
 102           && p_ref_ == break_item_)
 103         {
 104           Item *it = make_item ("StaffSpacing", SCM_EOL);
 105           current_spacings_.staff_spacing_ = it;
 106           Pointer_group_interface::add_grob (it, ly_symbol2scm ("left-items"),
 107                                              break_item_);
 108
 109           if (!last_spacings_.note_spacings_.size ()
 110               && last_spacings_.staff_spacing_)
 111             {
 112               SCM ri = last_spacings_.staff_spacing_->get_object ("right-items");
 113               Grob_array *ga = unsmob_grob_array (ri);
 114               if (!ga)
 115                 {
 116                   SCM ga_scm = Grob_array::make_array ();
 117                   last_spacings_.staff_spacing_->set_object ("right-items", ga_scm);
 118                   ga = unsmob_grob_array (ga_scm);
 119                 }
 120
 121               ga->clear ();
 122               ga->add (break_item_);
 123             }
 124         }
 125     }
 126
 127   if (Accidental_placement::has_interface (it))
 128     Separation_item::add_conditional_item (p_ref_, it);
 129   else
 130     Separation_item::add_item (p_ref_, it);
 131 }
 132
 133 void
 134 Separating_line_group_engraver::start_translation_timestep ()
 135 {
 136   if (break_item_)
 137     {
 138       context ()->unset_property (ly_symbol2scm ("breakableSeparationItem"));
 139       break_item_ = 0;
 140     }
 141 }
 142
 143 void
 144 Separating_line_group_engraver::stop_translation_timestep ()
 145 {
 146   if (Item *sp = current_spacings_.staff_spacing_)
 147     {
 148       /*
 149         TODO: should really look at the left-items of following
 150         note-spacing grobs.
 151       */
 152       if (musical_item_)
 153         Pointer_group_interface::add_grob (sp, ly_symbol2scm ("right-items"),
 154                                            musical_item_);
 155     }
 156
 157   if (!current_spacings_.is_empty ())
 158     last_spacings_ = current_spacings_;
 159
 160   current_spacings_.clear ();
 161
 162   musical_item_ = 0;
 163 }
 164
 165 ADD_ACKNOWLEDGER (Separating_line_group_engraver, item);
 166 ADD_TRANSLATOR (Separating_line_group_engraver,
 167                 /* doc */ "Generates objects for computing spacing parameters.",
 168
 169                 /* create */
 170                 "SeparationItem "
 171                 "SeparatingGroupSpanner "
 172                 "StaffSpacing",
 173                 /* read */ "createSpacing",
 174                 /* write */ "breakableSeparationItem");