lily/item.cc

   1 /*
   2   item.cc -- implement Item
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2000 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   : Score_element (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   : Score_element (s)
  29 {
  30   broken_to_drul_[LEFT] = broken_to_drul_[RIGHT] =0;
  31 }
  32
  33
  34 bool
  35 Item::breakable_b (Score_element*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_elt_property ("breakable"));
  45 }
  46
  47 Paper_column *
  48 Item::column_l () const
  49 {
  50   return dynamic_cast<Item*> (parent_l (X_AXIS))->column_l ();
  51 }
  52
  53 Line_of_score *
  54 Item::line_l() const
  55 {
  56   Score_element *g = parent_l (X_AXIS);
  57   return g ?  g->line_l () : 0;
  58 }
  59
  60
  61 void
  62 Item::copy_breakable_items()
  63 {
  64   Drul_array<Item *> new_copies;
  65   Direction  i=LEFT;
  66   do
  67     {
  68       Score_element * dolly = clone();
  69       Item * item_p = dynamic_cast<Item*>(dolly);
  70       pscore_l_->line_l_->typeset_element (item_p);
  71       new_copies[i] =item_p;
  72     }
  73   while (flip(&i) != LEFT);
  74   broken_to_drul_= new_copies;
  75 }
  76
  77
  78 bool
  79 Item::broken_b () const
  80 {
  81   return broken_to_drul_[LEFT] || broken_to_drul_[RIGHT];
  82 }
  83
  84
  85 /*
  86   Generate items for begin and end-of line.
  87  */
  88 void
  89 Item::discretionary_processing()
  90 {
  91   if (broken_b ())
  92     return;
  93
  94   if (Item::breakable_b (this))
  95     copy_breakable_items();
  96 }
  97
  98 Score_element*
  99 Item::find_broken_piece (Line_of_score*l) const
 100 {
 101   if (line_l() == l)
 102     return (Item*)(this);
 103
 104   Direction d = LEFT;
 105   do {
 106     Score_element *s = broken_to_drul_[d];
 107     if (s && s->line_l () == l)
 108       return s;
 109   }
 110   while (flip (&d) != LEFT);
 111
 112   return 0;
 113 }
 114
 115
 116 Item*
 117 Item::find_prebroken_piece (Direction d) const
 118 {
 119   Item * me = (Item *) (this);
 120   if (!d)
 121     return me;
 122   return dynamic_cast<Item*> (broken_to_drul_[d]);
 123 }
 124
 125
 126 Direction
 127 Item::break_status_dir () const
 128 {
 129   if (original_l_)
 130     {
 131       Item * i = dynamic_cast<Item*> (original_l_);
 132
 133       return (i->broken_to_drul_[LEFT] == this) ? LEFT : RIGHT;
 134     }
 135   else
 136     return CENTER;
 137 }
 138
 139 void
 140 Item::handle_prebroken_dependencies ()
 141 {
 142   if (original_l_)
 143     {
 144       mutable_property_alist_
 145         = handle_broken_smobs (original_l_->mutable_property_alist_,
 146                                gh_int2scm (break_status_dir ()));
 147     }
 148
 149   /*
 150     Can't do this earlier, because try_visibility_lambda () might set
 151     the elt property transparent, which would then be copied.
 152
 153     TODO:
 154
 155     handle visibility-lambda the item itself iso. breakstatusdir, so
 156     the function can do more complicated things.
 157
 158   */
 159   SCM vis = get_elt_property ("visibility-lambda");
 160   if (gh_procedure_p (vis))
 161     {
 162       SCM args = scm_listify (gh_int2scm (break_status_dir ()), SCM_UNDEFINED);
 163       SCM result = gh_apply (vis, args);
 164       bool trans = gh_scm2bool (gh_car (result));
 165       bool empty = gh_scm2bool (gh_cdr (result));
 166
 167       if (empty && trans)
 168         suicide ();
 169       else if (empty)
 170         {
 171           set_extent_callback (0, X_AXIS);
 172           set_extent_callback (0,  Y_AXIS);
 173         }
 174       else if (trans)
 175         set_elt_property ("molecule-callback", SCM_BOOL_T);
 176     }
 177 }
 178
 179 SCM
 180 Item::do_derived_mark ()
 181 {
 182   if (broken_to_drul_[LEFT])
 183     scm_gc_mark (broken_to_drul_[LEFT]->self_scm ());
 184   if (broken_to_drul_[RIGHT])
 185     scm_gc_mark (broken_to_drul_[RIGHT]->self_scm ());
 186   return SCM_EOL;
 187 }