lily/item.cc

   1 /*
   2   item.cc -- implement Item
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9
  10 #include "paper-score.hh"
  11 #include "debug.hh"
  12 #include "item.hh"
  13 #include "paper-column.hh"
  14 #include "spanner.hh"
  15 #include "lily-guile.hh"
  16 #include "line-of-score.hh"
  17
  18 Item::Item (SCM s)
  19   : Grob (s)
  20 {
  21   broken_to_drul_[LEFT] = broken_to_drul_[RIGHT]=0;
  22 }
  23
  24 /**
  25    Item copy ctor.  Copy nothing: everything should be a elt property
  26    or a special purpose pointer (such as broken_to_drul_[]) */
  27 Item::Item (Item const &s)
  28   : Grob (s)
  29 {
  30   broken_to_drul_[LEFT] = broken_to_drul_[RIGHT] =0;
  31 }
  32
  33
  34 bool
  35 Item::breakable_b (Grob*me)
  36 {
  37   if (me->original_l_)
  38     return false;
  39
  40   if (!dynamic_cast<Item*> (me))
  41     programming_error ("only items can be breakable.");
  42
  43   Item * i  =dynamic_cast<Item*> (me->parent_l (X_AXIS));
  44   return (i) ?  Item::breakable_b (i) : to_boolean (me->get_grob_property ("breakable"));
  45 }
  46
  47 Paper_column *
  48 Item::column_l () const
  49 {
  50   Item *parent = dynamic_cast<Item*> (parent_l (X_AXIS));
  51   return parent ? parent->column_l () : 0;
  52 }
  53
  54 Line_of_score *
  55 Item::line_l () const
  56 {
  57   Grob *g = parent_l (X_AXIS);
  58   return g ?  g->line_l () : 0;
  59 }
  60
  61
  62 void
  63 Item::copy_breakable_items ()
  64 {
  65   Drul_array<Item *> new_copies;
  66   Direction  i=LEFT;
  67   do
  68     {
  69       Grob * dolly = clone ();
  70       Item * item_p = dynamic_cast<Item*> (dolly);
  71       pscore_l_->line_l_->typeset_grob (item_p);
  72       new_copies[i] =item_p;
  73     }
  74   while (flip (&i) != LEFT);
  75   broken_to_drul_= new_copies;
  76 }
  77
  78
  79 bool
  80 Item::broken_b () const
  81 {
  82   return broken_to_drul_[LEFT] || broken_to_drul_[RIGHT];
  83 }
  84
  85
  86 /*
  87   Generate items for begin and end-of line.
  88  */
  89 void
  90 Item::discretionary_processing ()
  91 {
  92   if (broken_b ())
  93     return;
  94
  95   if (Item::breakable_b (this))
  96     copy_breakable_items ();
  97 }
  98
  99 Grob*
 100 Item::find_broken_piece (Line_of_score*l) const
 101 {
 102   if (line_l () == l)
 103     return (Item*) (this);
 104
 105   Direction d = LEFT;
 106   do {
 107     Grob *s = broken_to_drul_[d];
 108     if (s && s->line_l () == l)
 109       return s;
 110   }
 111   while (flip (&d) != LEFT);
 112
 113   return 0;
 114 }
 115
 116
 117 Item*
 118 Item::find_prebroken_piece (Direction d) const
 119 {
 120   Item * me = (Item *) (this);
 121   if (!d)
 122     return me;
 123   return dynamic_cast<Item*> (broken_to_drul_[d]);
 124 }
 125
 126
 127 Direction
 128 Item::break_status_dir () const
 129 {
 130   if (original_l_)
 131     {
 132       Item * i = dynamic_cast<Item*> (original_l_);
 133
 134       return (i->broken_to_drul_[LEFT] == this) ? LEFT : RIGHT;
 135     }
 136   else
 137     return CENTER;
 138 }
 139
 140 void
 141 Item::handle_prebroken_dependencies ()
 142 {
 143   if (original_l_)
 144     {
 145       mutable_property_alist_
 146         = handle_broken_grobs(original_l_->mutable_property_alist_,
 147                                gh_int2scm (break_status_dir ()));
 148     }
 149
 150   /*
 151     Can't do this earlier, because try_visibility_lambda () might set
 152     the elt property transparent, which would then be copied.
 153
 154     TODO:
 155
 156     handle visibility-lambda the item itself iso. breakstatusdir, so
 157     the function can do more complicated things.
 158
 159   */
 160   SCM vis = get_grob_property ("visibility-lambda");
 161   if (gh_procedure_p (vis))
 162     {
 163       SCM args = scm_list_n (gh_int2scm (break_status_dir ()), SCM_UNDEFINED);
 164       SCM result = gh_apply (vis, args);
 165       bool trans = gh_scm2bool (gh_car (result));
 166       bool empty = gh_scm2bool (gh_cdr (result));
 167
 168       if (empty && trans)
 169         suicide ();
 170       else if (empty)
 171         {
 172           set_extent_callback (SCM_EOL, X_AXIS);
 173           set_extent_callback (SCM_EOL, Y_AXIS);
 174         }
 175       else if (trans)
 176         set_grob_property ("molecule-callback", SCM_BOOL_T);
 177     }
 178 }
 179
 180 SCM
 181 Item::do_derived_mark ()
 182 {
 183   if (broken_to_drul_[LEFT])
 184     scm_gc_mark (broken_to_drul_[LEFT]->self_scm ());
 185   if (broken_to_drul_[RIGHT])
 186     scm_gc_mark (broken_to_drul_[RIGHT]->self_scm ());
 187   return SCM_EOL;
 188 }