lily/break-align-item.cc

   1 /*
   2   break-align-item.cc -- implement Break_align_interface
   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 <math.h>
  11 #include <libc-extension.hh>    // isinf
  12
  13 #include "side-position-interface.hh"
  14 #include "axis-group-interface.hh"
  15 #include "warn.hh"
  16 #include "lily-guile.hh"
  17 #include "break-align-item.hh"
  18 #include "dimensions.hh"
  19 #include "paper-def.hh"
  20 #include "paper-column.hh"
  21 #include "group-interface.hh"
  22 #include "align-interface.hh"
  23
  24 MAKE_SCHEME_CALLBACK (Break_align_interface,before_line_breaking,1);
  25
  26 SCM
  27 Break_align_interface::before_line_breaking (SCM smob)
  28 {
  29   Grob* me = unsmob_grob (smob);
  30   do_alignment (me);
  31   return SCM_UNSPECIFIED;
  32 }
  33 MAKE_SCHEME_CALLBACK (Break_align_interface,alignment_callback,2);
  34
  35 SCM
  36 Break_align_interface::alignment_callback (SCM element_smob, SCM axis)
  37 {
  38   Grob *me = unsmob_grob (element_smob);
  39   Axis a = (Axis) gh_scm2int (axis);
  40
  41   assert (a == X_AXIS);
  42   Grob *par = me->parent_l (a);
  43   if (par && !to_boolean (par->get_grob_property ("break-alignment-done")))\
  44     {
  45       par->set_grob_property ("break-alignment-done", SCM_BOOL_T);
  46       Break_align_interface::do_alignment (par);
  47     }
  48
  49   return gh_double2scm (0);
  50 }
  51
  52 MAKE_SCHEME_CALLBACK (Break_align_interface,self_align_callback,2);
  53 SCM
  54 Break_align_interface::self_align_callback (SCM element_smob, SCM axis)
  55 {
  56   Grob *me = unsmob_grob (element_smob);
  57   Axis a = (Axis) gh_scm2int (axis);
  58   assert (a == X_AXIS);
  59
  60   Item* item = dynamic_cast<Item*> (me);
  61   Direction bsd = item->break_status_dir ();
  62   if (bsd == LEFT)
  63     {
  64       me->set_grob_property ("self-alignment-X", gh_int2scm (RIGHT));
  65     }
  66
  67   /*
  68     Force break alignment itself to be done first, in the case
  69    */
  70
  71
  72   return Side_position_interface::aligned_on_self (element_smob, axis);
  73 }
  74
  75 void
  76 Break_align_interface::add_element (Grob*me, Grob *toadd)
  77 {
  78   Axis_group_interface::add_element (me, toadd);
  79 }
  80
  81 void
  82 Break_align_interface::do_alignment (Grob *me)
  83 {
  84   Item * item = dynamic_cast<Item*> (me);
  85   Item *column = item->column_l ();
  86
  87   Link_array<Grob> elems;
  88   Link_array<Grob> all_elems
  89     = Pointer_group_interface__extract_elements (me, (Grob*)0,
  90                                                  "elements");
  91
  92   for (int i=0; i < all_elems.size (); i++)
  93     {
  94       Interval y = all_elems[i]->extent (all_elems[i], X_AXIS);
  95       if (!y.empty_b ())
  96         elems.push (dynamic_cast<Grob*> (all_elems[i]));
  97     }
  98
  99   if (!elems.size ())
 100     return;
 101
 102   SCM symbol_list = SCM_EOL;
 103   Array<Real> dists;
 104   SCM current_origin = ly_symbol2scm ("none");
 105   for (int i=0; i <= elems.size (); i++)
 106     {
 107       Grob *next_elt  = i < elems.size ()
 108         ? elems[i]
 109         : 0 ;
 110
 111       SCM next_origin;
 112
 113       if (next_elt)
 114         {
 115           next_origin = next_elt->get_grob_property ("break-align-symbol");
 116           next_origin =
 117             gh_symbol_p (next_origin)?
 118             next_origin : ly_symbol2scm ("none")
 119 ;
 120         }
 121       else
 122         next_origin = ly_symbol2scm ("begin-of-note");
 123
 124       SCM alist = me->get_grob_property ("space-alist");
 125       SCM e = scm_assoc (scm_list_n (current_origin,
 126                                       next_origin,
 127                                       SCM_UNDEFINED), alist);
 128
 129       SCM extra_space;
 130       if (e != SCM_BOOL_F)
 131         {
 132           extra_space = gh_cdr (e);
 133         }
 134       else
 135         {
 136           warning (_f ("unknown spacing pair `%s', `%s'",
 137                        ly_symbol2string (current_origin),
 138                        ly_symbol2string (next_origin)));
 139           extra_space = scm_list_n (ly_symbol2scm ("minimum-space"), gh_double2scm (0.0), SCM_UNDEFINED);
 140         }
 141
 142       SCM symbol = gh_car (extra_space);
 143       Real spc = gh_scm2double (gh_cadr (extra_space));
 144
 145       dists.push (spc);
 146       symbol_list = gh_cons (symbol, symbol_list);
 147       current_origin = next_origin;
 148     }
 149
 150
 151   // skip the first sym.
 152   symbol_list  = gh_cdr (scm_reverse (symbol_list));
 153   for (int i=0; i <elems.size ()-1; i++)
 154     {
 155       elems[i]->set_grob_property (gh_car (symbol_list),
 156                                   scm_cons (gh_double2scm (0),
 157                                             gh_double2scm (dists[i+1])));
 158
 159       symbol_list = gh_cdr (symbol_list);
 160     }
 161
 162
 163   // urg
 164   SCM first_pair = elems[0]->get_grob_property ("minimum-space");
 165   if (gh_pair_p (first_pair))
 166     first_pair = first_pair;
 167   else
 168     first_pair = gh_cons (gh_double2scm (0.0), gh_double2scm (0.0));
 169
 170   scm_set_car_x (first_pair, gh_double2scm (-dists[0]));
 171   elems[0]->set_grob_property ("minimum-space", first_pair);
 172
 173   Direction bsd = item->break_status_dir ();
 174   if (bsd == LEFT)
 175     {
 176       me->set_grob_property ("self-alignment-X", gh_int2scm (RIGHT));
 177     }
 178
 179   /*
 180     Force callbacks for alignment to be called
 181   */
 182   Align_interface::align_elements_to_extents (me, X_AXIS);
 183
 184   Real pre_space = elems[0]->relative_coordinate (column, X_AXIS);
 185
 186   Real xl = elems[0]->extent (elems[0],X_AXIS)[LEFT];
 187   if (!isinf (xl))
 188     pre_space += xl;
 189   else
 190     programming_error ("Infinity reached. ");
 191
 192   Real xr = elems.top ()->extent (elems.top (), X_AXIS)[RIGHT];
 193   Real spring_len = elems.top ()->relative_coordinate (column, X_AXIS);
 194   if (!isinf (xr))
 195     spring_len += xr;
 196   else
 197     programming_error ("Infinity reached.");
 198
 199   Real stretch_distance =0.;
 200
 201   if (gh_car (symbol_list) == ly_symbol2scm ("extra-space"))
 202     {
 203       spring_len += dists.top ();
 204       stretch_distance = dists.top ();
 205     }
 206   else if (gh_car (symbol_list) == ly_symbol2scm ("minimum-space"))
 207     {
 208       spring_len = spring_len >? dists.top ();
 209       stretch_distance = spring_len;
 210     }
 211
 212
 213   /*
 214     Hint the spacing engine how much space to put in.
 215
 216     The pairs are in the format of an interval (ie. CAR <  CDR).
 217   */
 218   /*
 219     UGH UGH UGH
 220
 221     This is a side effect, and there is no guarantee that this info is
 222     computed at a "sane" moment.
 223
 224  (just spent some time tracking a bug that was caused by this info
 225     being written halfway:
 226
 227     self_alignment_callback (*)
 228     -> child->relative_coordinate (self)
 229     -> break_alignment
 230     -> child->relative_coordinate (column)
 231
 232     the last call incorporates the value that should've been computed
 233     in (*), but--of course-- is not yet.
 234
 235     The result is that an offsets of align_elements_to_extents () are
 236     not compensated for, and spring_len is completely off.
 237
 238
 239   */
 240   column->set_grob_property ("extra-space",
 241                             scm_cons (gh_double2scm (pre_space),
 242                                       gh_double2scm (spring_len)));
 243
 244   column->set_grob_property ("stretch-distance",
 245                             gh_cons (gh_double2scm (-dists[0]),
 246                                      gh_double2scm (stretch_distance)));
 247 }
 248
 249
 250 void
 251 Break_align_interface::set_interface (Grob*me)
 252 {
 253   Align_interface::set_interface (me);
 254   Align_interface::set_axis (me,X_AXIS);
 255 }