lily/item.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2011 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "item.hh"
  21
  22 #include "axis-group-interface.hh"
  23 #include "paper-score.hh"
  24 #include "warn.hh"
  25 #include "paper-column.hh"
  26 #include "lily-guile.hh"
  27 #include "system.hh"
  28 #include "pointer-group-interface.hh"
  29
  30 #include "moment.hh"
  31
  32
  33 Grob *
  34 Item::clone () const
  35 {
  36   return new Item (*this);
  37 }
  38
  39 Item::Item (SCM s)
  40   : Grob (s)
  41 {
  42   broken_to_drul_[LEFT] = broken_to_drul_[RIGHT] = 0;
  43   cached_pure_height_valid_ = false;
  44 }
  45
  46 /**
  47    Item copy ctor.  Copy nothing: everything should be a elt property
  48    or a special purpose pointer (such as broken_to_drul_[]) */
  49 Item::Item (Item const &s)
  50   : Grob (s)
  51 {
  52   broken_to_drul_[LEFT] = broken_to_drul_[RIGHT] = 0;
  53   cached_pure_height_valid_ = false;
  54 }
  55
  56 bool
  57 Item::is_non_musical (Grob *me)
  58 {
  59   if (me->original ())
  60     return false;
  61
  62   Item *i = dynamic_cast<Item *> (me->get_parent (X_AXIS));
  63   return i ? Item::is_non_musical (i) : to_boolean (me->get_property ("non-musical"));
  64 }
  65
  66 Paper_column *
  67 Item::get_column () const
  68 {
  69   Item *parent = dynamic_cast<Item *> (get_parent (X_AXIS));
  70   return parent ? parent->get_column () : 0;
  71 }
  72
  73 System *
  74 Item::get_system () const
  75 {
  76   Grob *g = get_parent (X_AXIS);
  77   return g ? g->get_system () : 0;
  78 }
  79
  80 void
  81 Item::copy_breakable_items ()
  82 {
  83   Drul_array<Item *> new_copies;
  84   Direction i = LEFT;
  85   do
  86     {
  87       Grob *dolly = clone ();
  88       Item *item = dynamic_cast<Item *> (dolly);
  89       get_root_system (this)->typeset_grob (item);
  90       new_copies[i] = item;
  91     }
  92   while (flip (&i) != LEFT);
  93
  94   broken_to_drul_ = new_copies;
  95 }
  96
  97 bool
  98 Item::is_broken () const
  99 {
 100   return broken_to_drul_[LEFT] || broken_to_drul_[RIGHT];
 101 }
 102
 103 /*
 104   Generate items for begin and end-of line.
 105 */
 106 void
 107 Item::discretionary_processing ()
 108 {
 109   if (is_broken ())
 110     return;
 111
 112   if (Item::is_non_musical (this))
 113     copy_breakable_items ();
 114 }
 115
 116 Grob *
 117 Item::find_broken_piece (System *l) const
 118 {
 119   if (get_system () == l)
 120     return (Item *) (this);
 121
 122   Direction d = LEFT;
 123   do
 124     {
 125       Grob *s = broken_to_drul_[d];
 126       if (s && s->get_system () == l)
 127         return s;
 128     }
 129   while (flip (&d) != LEFT);
 130
 131   return 0;
 132 }
 133
 134 Item *
 135 Item::find_prebroken_piece (Direction d) const
 136 {
 137   Item *me = (Item *) (this);
 138   if (!d)
 139     return me;
 140   return dynamic_cast<Item *> (broken_to_drul_[d]);
 141 }
 142
 143 Direction
 144 Item::break_status_dir () const
 145 {
 146   if (original ())
 147     {
 148       Item *i = dynamic_cast<Item *> (original ());
 149
 150       return (i->broken_to_drul_[LEFT] == this) ? LEFT : RIGHT;
 151     }
 152   else
 153     return CENTER;
 154 }
 155
 156 void
 157 Item::handle_prebroken_dependencies ()
 158 {
 159   Grob::handle_prebroken_dependencies ();
 160
 161   /*
 162     Can't do this earlier, because try_visibility_lambda () might set
 163     the elt property transparent, which would then be copied.
 164   */
 165   if (!Item::break_visible (this))
 166     suicide ();
 167 }
 168
 169 bool
 170 Item::break_visible (Grob *g)
 171 {
 172   Item *it = dynamic_cast<Item*> (g);
 173   SCM vis = g->get_property ("break-visibility");
 174   if (scm_is_vector (vis))
 175     return to_boolean (scm_c_vector_ref (vis, it->break_status_dir () + 1));
 176   return true;
 177 }
 178
 179 bool
 180 Item::pure_is_visible (int start, int end) const
 181 {
 182   SCM vis = get_property ("break-visibility");
 183   if (scm_is_vector (vis))
 184     {
 185       int pos = 1;
 186       int pc_rank = Paper_column::get_rank (get_column ());
 187       if (pc_rank == start)
 188         pos = 2;
 189       else if (pc_rank == end)
 190         pos = 0;
 191       return to_boolean (scm_vector_ref (vis, scm_from_int (pos)));
 192     }
 193   return true;
 194 }
 195
 196 Interval_t<int>
 197 Item::spanned_rank_interval () const
 198 {
 199   int c = get_column ()->get_rank ();
 200   return Interval_t<int> (c, c);
 201 }
 202
 203 Interval_t<Moment>
 204 spanned_time_interval (Item *l, Item *r)
 205 {
 206   Drul_array<Item*> bounds (l, r);
 207   Interval_t<Moment> iv;
 208
 209   Direction d = LEFT;
 210   do
 211     {
 212       if (bounds[d] && bounds[d]->get_column ())
 213         iv[d] = robust_scm2moment (bounds[d]->get_column ()->get_property ("when"),
 214                                   iv[d]);
 215     }
 216   while (flip (&d) != LEFT);
 217
 218   do
 219     {
 220       if (!bounds[d] || !bounds[d]->get_column ())
 221         iv[d] = iv[-d];
 222     }
 223   while (flip (&d) != LEFT);
 224
 225
 226   return iv;
 227 }
 228
 229
 230 void
 231 Item::derived_mark () const
 232 {
 233   if (broken_to_drul_[LEFT])
 234     scm_gc_mark (broken_to_drul_[LEFT]->self_scm ());
 235   if (broken_to_drul_[RIGHT])
 236     scm_gc_mark (broken_to_drul_[RIGHT]->self_scm ());
 237 }
 238
 239 Item *
 240 unsmob_item (SCM s)
 241 {
 242   return dynamic_cast<Item *> (unsmob_grob (s));
 243 }
 244
 245 Interval
 246 Item::pure_height (Grob *g, int start, int end)
 247 {
 248   if (cached_pure_height_valid_)
 249     return cached_pure_height_ + pure_relative_y_coordinate (g, start, end);
 250
 251   cached_pure_height_ = Grob::pure_height (this, start, end);
 252   cached_pure_height_valid_ = true;
 253   return cached_pure_height_ + pure_relative_y_coordinate (g, start, end);
 254 }
 255
 256 ADD_INTERFACE (Item,
 257                "Grobs can be distinguished in their role in the horizontal"
 258                " spacing.  Many grobs define constraints on the spacing by"
 259                " their sizes, for example, note heads, clefs, stems, and all"
 260                " other symbols with a fixed shape.  These grobs form a"
 261                " subtype called @code{Item}.\n"
 262                "\n"
 263                "Some items need special treatment for line breaking.  For"
 264                " example, a clef is normally only printed at the start of a"
 265                " line (i.e., after a line break).   To model this,"
 266                " @q{breakable} items (clef, key signature, bar lines, etc.)"
 267                " are copied twice.  Then we have three versions of each"
 268                " breakable item: one version if there is no line break, one"
 269                " version that is printed before the line break (at the end of"
 270                " a system), and one version that is printed after the line"
 271                " break.\n"
 272                "\n"
 273                "Whether these versions are visible and take up space is"
 274                " determined by the outcome of the @code{break-visibility}"
 275                " grob property, which is a function taking a direction"
 276                " (@code{-1}, @code{0} or@tie{}@code{1}) as an argument.  It"
 277                " returns a cons of booleans, signifying whether this grob"
 278                " should be transparent and have no extent.\n"
 279                "\n"
 280                "The following variables for @code{break-visibility} are"
 281                " predefined:\n"
 282                "@example\n"
 283                "           grob will show:   before  no     after\n"
 284                "                             break   break  break\n"
 285                "  all-invisible              no      no     no\n"
 286                "  begin-of-line-visible      no      no     yes\n"
 287                "  end-of-line-visible        yes     no     no\n"
 288                "  all-visible                yes     yes    yes\n"
 289                "  begin-of-line-invisible    yes     yes    no\n"
 290                "  end-of-line-invisible      no      yes    yes\n"
 291                "  center-invisible           yes      no    yes\n"
 292                "@end example",
 293
 294                /* properties */
 295                "break-visibility "
 296                "extra-spacing-height "
 297                "extra-spacing-width "
 298                "non-musical "
 299                );