lily/item.cc

   1 /*
   2   item.cc -- implement Item
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2008 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "item.hh"
  10
  11 #include "axis-group-interface.hh"
  12 #include "paper-score.hh"
  13 #include "warn.hh"
  14 #include "paper-column.hh"
  15 #include "lily-guile.hh"
  16 #include "system.hh"
  17 #include "pointer-group-interface.hh"
  18
  19 #include "moment.hh"
  20
  21
  22 Grob *
  23 Item::clone () const
  24 {
  25   return new Item (*this);
  26 }
  27
  28 Item::Item (SCM s)
  29   : Grob (s)
  30 {
  31   broken_to_drul_[LEFT] = broken_to_drul_[RIGHT] = 0;
  32   cached_pure_height_valid_ = false;
  33 }
  34
  35 /**
  36    Item copy ctor.  Copy nothing: everything should be a elt property
  37    or a special purpose pointer (such as broken_to_drul_[]) */
  38 Item::Item (Item const &s)
  39   : Grob (s)
  40 {
  41   broken_to_drul_[LEFT] = broken_to_drul_[RIGHT] = 0;
  42   cached_pure_height_valid_ = false;
  43 }
  44
  45 bool
  46 Item::is_non_musical (Grob *me)
  47 {
  48   if (me->original ())
  49     return false;
  50
  51   Item *i = dynamic_cast<Item *> (me->get_parent (X_AXIS));
  52   return i ? Item::is_non_musical (i) : to_boolean (me->get_property ("non-musical"));
  53 }
  54
  55 Paper_column *
  56 Item::get_column () const
  57 {
  58   Item *parent = dynamic_cast<Item *> (get_parent (X_AXIS));
  59   return parent ? parent->get_column () : 0;
  60 }
  61
  62 System *
  63 Item::get_system () const
  64 {
  65   Grob *g = get_parent (X_AXIS);
  66   return g ? g->get_system () : 0;
  67 }
  68
  69 void
  70 Item::copy_breakable_items ()
  71 {
  72   Drul_array<Item *> new_copies;
  73   Direction i = LEFT;
  74   do
  75     {
  76       Grob *dolly = clone ();
  77       Item *item = dynamic_cast<Item *> (dolly);
  78       get_root_system (this)->typeset_grob (item);
  79       new_copies[i] = item;
  80     }
  81   while (flip (&i) != LEFT);
  82
  83   broken_to_drul_ = new_copies;
  84 }
  85
  86 bool
  87 Item::is_broken () const
  88 {
  89   return broken_to_drul_[LEFT] || broken_to_drul_[RIGHT];
  90 }
  91
  92 /*
  93   Generate items for begin and end-of line.
  94 */
  95 void
  96 Item::discretionary_processing ()
  97 {
  98   if (is_broken ())
  99     return;
 100
 101   if (Item::is_non_musical (this))
 102     copy_breakable_items ();
 103 }
 104
 105 Grob *
 106 Item::find_broken_piece (System *l) const
 107 {
 108   if (get_system () == l)
 109     return (Item *) (this);
 110
 111   Direction d = LEFT;
 112   do
 113     {
 114       Grob *s = broken_to_drul_[d];
 115       if (s && s->get_system () == l)
 116         return s;
 117     }
 118   while (flip (&d) != LEFT);
 119
 120   return 0;
 121 }
 122
 123 Item *
 124 Item::find_prebroken_piece (Direction d) const
 125 {
 126   Item *me = (Item *) (this);
 127   if (!d)
 128     return me;
 129   return dynamic_cast<Item *> (broken_to_drul_[d]);
 130 }
 131
 132 Direction
 133 Item::break_status_dir () const
 134 {
 135   if (original ())
 136     {
 137       Item *i = dynamic_cast<Item *> (original ());
 138
 139       return (i->broken_to_drul_[LEFT] == this) ? LEFT : RIGHT;
 140     }
 141   else
 142     return CENTER;
 143 }
 144
 145 void
 146 Item::handle_prebroken_dependencies ()
 147 {
 148   Grob::handle_prebroken_dependencies ();
 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   if (!Item::break_visible (this))
 155     suicide ();
 156 }
 157
 158 bool
 159 Item::break_visible (Grob *g)
 160 {
 161   Item *it = dynamic_cast<Item*> (g);
 162   SCM vis = g->get_property ("break-visibility");
 163   if (scm_is_vector (vis))
 164     return to_boolean (scm_c_vector_ref (vis, it->break_status_dir () + 1));
 165   return true;
 166 }
 167
 168 bool
 169 Item::pure_is_visible (int start, int end) const
 170 {
 171   SCM vis = get_property ("break-visibility");
 172   if (scm_is_vector (vis))
 173     {
 174       int pos = 1;
 175       int pc_rank = Paper_column::get_rank (get_column ());
 176       if (pc_rank == start)
 177         pos = 2;
 178       else if (pc_rank == end)
 179         pos = 0;
 180       return to_boolean (scm_vector_ref (vis, scm_from_int (pos)));
 181     }
 182   return true;
 183 }
 184
 185 Interval_t<int>
 186 Item::spanned_rank_interval () const
 187 {
 188   int c = get_column ()->get_rank ();
 189   return Interval_t<int> (c, c);
 190 }
 191
 192 Interval_t<Moment>
 193 spanned_time_interval (Item *l, Item *r)
 194 {
 195   Drul_array<Item*> bounds (l, r);
 196   Interval_t<Moment> iv;
 197
 198   Direction d = LEFT;
 199   do
 200     {
 201       if (bounds[d] && bounds[d]->get_column ())
 202         iv[d] = robust_scm2moment (bounds[d]->get_column ()->get_property ("when"),
 203                                   iv[d]);
 204     }
 205   while (flip (&d) != LEFT);
 206
 207   do
 208     {
 209       if (!bounds[d] || !bounds[d]->get_column ())
 210         iv[d] = iv[-d];
 211     }
 212   while (flip (&d) != LEFT);
 213
 214
 215   return iv;
 216 }
 217
 218
 219 void
 220 Item::derived_mark () const
 221 {
 222   if (broken_to_drul_[LEFT])
 223     scm_gc_mark (broken_to_drul_[LEFT]->self_scm ());
 224   if (broken_to_drul_[RIGHT])
 225     scm_gc_mark (broken_to_drul_[RIGHT]->self_scm ());
 226 }
 227
 228 Item *
 229 unsmob_item (SCM s)
 230 {
 231   return dynamic_cast<Item *> (unsmob_grob (s));
 232 }
 233
 234 Interval
 235 Item::pure_height (Grob *g, int start, int end)
 236 {
 237   if (cached_pure_height_valid_)
 238     return cached_pure_height_ + pure_relative_y_coordinate (g, start, end);
 239
 240   cached_pure_height_ = Grob::pure_height (this, start, end);
 241   cached_pure_height_valid_ = true;
 242   return cached_pure_height_ + pure_relative_y_coordinate (g, start, end);
 243 }
 244
 245 bool
 246 Item::less (Grob * const &g1, Grob * const &g2)
 247 {
 248   return dynamic_cast<Item*> (g1)->get_column ()->get_rank () < dynamic_cast<Item*> (g2)->get_column ()->get_rank ();
 249 }
 250
 251 ADD_INTERFACE (Item,
 252                "Grobs can be distinguished in their role in the horizontal"
 253                " spacing.  Many grobs define constraints on the spacing by"
 254                " their sizes, for example, note heads, clefs, stems, and all"
 255                " other symbols with a fixed shape.  These grobs form a"
 256                " subtype called @code{Item}.\n"
 257                "\n"
 258                "Some items need special treatment for line breaking.  For"
 259                " example, a clef is normally only printed at the start of a"
 260                " line (i.e., after a line break).   To model this,"
 261                " @q{breakable} items (clef, key signature, bar lines, etc.)"
 262                " are copied twice.  Then we have three versions of each"
 263                " breakable item: one version if there is no line break, one"
 264                " version that is printed before the line break (at the end of"
 265                " a system), and one version that is printed after the line"
 266                " break.\n"
 267                "\n"
 268                "Whether these versions are visible and take up space is"
 269                " determined by the outcome of the @code{break-visibility}"
 270                " grob property, which is a function taking a direction"
 271                " (@code{-1}, @code{0} or@tie{}@code{1}) as an argument.  It"
 272                " returns a cons of booleans, signifying whether this grob"
 273                " should be transparent and have no extent.\n"
 274                "\n"
 275                "The following variables for @code{break-visibility} are"
 276                " predefined:\n"
 277                "@example\n"
 278                "           grob will show:   before  no     after\n"
 279                "                             break   break  break\n"
 280                "  all-invisible              no      no     no\n"
 281                "  begin-of-line-visible      no      no     yes\n"
 282                "  end-of-line-visible        yes     no     no\n"
 283                "  all-visible                yes     yes    yes\n"
 284                "  begin-of-line-invisible    yes     yes    no\n"
 285                "  end-of-line-invisible      no      yes    yes\n"
 286                "  center-invisible           yes      no    yes\n"
 287                "@end example",
 288
 289                /* properties */
 290                "break-visibility "
 291                "extra-spacing-height "
 292                "extra-spacing-width "
 293                "non-musical "
 294                );