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 "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 "spanner.hh"
  20 #include "grob-array.hh"
  21 #include "pointer-group-interface.hh"
  22
  23 #include "translator.icc"
  24
  25 struct Spacings
  26 {
  27   Item *staff_spacing_;
  28   vector<Item*> note_spacings_;
  29
  30   Spacings ()
  31   {
  32     staff_spacing_ = 0;
  33   }
  34
  35   bool is_empty () const
  36   {
  37     return !staff_spacing_ && !note_spacings_.size ();
  38   }
  39   void clear ()
  40   {
  41     staff_spacing_ = 0;
  42     note_spacings_.clear ();
  43   }
  44 };
  45
  46 class Separating_line_group_engraver : public Engraver
  47 {
  48 protected:
  49   Item *break_item_;
  50   Item *musical_item_;
  51   Item *last_musical_item_;
  52
  53   Spacings current_spacings_;
  54   Spacings last_spacings_;
  55
  56   DECLARE_ACKNOWLEDGER (item);
  57   void stop_translation_timestep ();
  58   void start_translation_timestep ();
  59 public:
  60   TRANSLATOR_DECLARATIONS (Separating_line_group_engraver);
  61 };
  62
  63 Separating_line_group_engraver::Separating_line_group_engraver ()
  64 {
  65   break_item_ = 0;
  66   musical_item_ = 0;
  67 }
  68
  69 void
  70 Separating_line_group_engraver::acknowledge_item (Grob_info i)
  71 {
  72   Item *it = i.item ();
  73   if (it->get_parent (X_AXIS)
  74       && it->get_parent (X_AXIS) == it->get_parent (Y_AXIS)
  75       && Axis_group_interface::has_axis (it->get_parent (X_AXIS), X_AXIS)
  76       && Axis_group_interface::has_axis (it->get_parent (Y_AXIS), Y_AXIS))
  77     return;
  78
  79   if (to_boolean (it->get_property ("no-spacing-rods")))
  80     return;
  81
  82   if (Note_spacing::has_interface (it))
  83     {
  84       current_spacings_.note_spacings_.push_back (it);
  85       return;
  86     }
  87
  88   bool ib = Item::is_non_musical (it);
  89   Item *&p_ref_ (ib ? break_item_
  90                  : musical_item_);
  91
  92   if (!p_ref_)
  93     {
  94       p_ref_ = make_item ("SeparationItem", SCM_EOL);
  95
  96       if (ib)
  97         {
  98           p_ref_->set_property ("non-musical", SCM_BOOL_T);
  99           context ()->set_property ("breakableSeparationItem", p_ref_->self_scm ());
 100         }
 101
 102       if (to_boolean (get_property ("createSpacing"))
 103           && p_ref_ == break_item_)
 104         {
 105           Item *it = make_item ("StaffSpacing", SCM_EOL);
 106           current_spacings_.staff_spacing_ = it;
 107           Pointer_group_interface::add_grob (it, ly_symbol2scm ("left-items"),
 108                                              break_item_);
 109
 110           if (!last_spacings_.note_spacings_.size ()
 111               && last_spacings_.staff_spacing_)
 112             {
 113               SCM ri = last_spacings_.staff_spacing_->get_object ("right-items");
 114               Grob_array *ga = unsmob_grob_array (ri);
 115               if (!ga)
 116                 {
 117                   SCM ga_scm = Grob_array::make_array ();
 118                   last_spacings_.staff_spacing_->set_object ("right-items", ga_scm);
 119                   ga = unsmob_grob_array (ga_scm);
 120                 }
 121
 122               ga->clear ();
 123               ga->add (break_item_);
 124             }
 125         }
 126     }
 127
 128   if (Accidental_placement::has_interface (it))
 129     Separation_item::add_conditional_item (p_ref_, it);
 130   else
 131     Separation_item::add_item (p_ref_, it);
 132 }
 133
 134 void
 135 Separating_line_group_engraver::start_translation_timestep ()
 136 {
 137   if (break_item_)
 138     {
 139       context ()->unset_property (ly_symbol2scm ("breakableSeparationItem"));
 140       break_item_ = 0;
 141     }
 142 }
 143
 144 void
 145 Separating_line_group_engraver::stop_translation_timestep ()
 146 {
 147   if (Item *sp = current_spacings_.staff_spacing_)
 148     {
 149       /*
 150         TODO: should really look at the left-items of following
 151         note-spacing grobs.
 152       */
 153       if (musical_item_)
 154         Pointer_group_interface::add_grob (sp, ly_symbol2scm ("right-items"),
 155                                            musical_item_);
 156     }
 157
 158   if (!current_spacings_.is_empty ())
 159     last_spacings_ = current_spacings_;
 160
 161   current_spacings_.clear ();
 162
 163   musical_item_ = 0;
 164 }
 165
 166 ADD_ACKNOWLEDGER (Separating_line_group_engraver, item);
 167 ADD_TRANSLATOR (Separating_line_group_engraver,
 168                 /* doc */ "Generates objects for computing spacing parameters.",
 169
 170                 /* create */
 171                 "SeparationItem "
 172                 "SeparatingGroupSpanner "
 173                 "StaffSpacing",
 174                 /* read */ "createSpacing",
 175                 /* write */ "breakableSeparationItem");