lily/break-align-item.cc

   1 /*
   2   break-align-item.cc -- implement Break_align_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 #include <math.h>
   9 #include <libc-extension.hh>
  10
  11 #include "side-position-interface.hh"
  12 #include "warn.hh"
  13 #include "dimension-cache.hh"
  14 #include "lily-guile.hh"
  15 #include "break-align-item.hh"
  16 #include "dimensions.hh"
  17 #include "paper-score.hh"
  18 #include "paper-def.hh"
  19 #include "paper-column.hh"
  20 #include "group-interface.hh"
  21 #include "align-interface.hh"
  22
  23 GLUE_SCORE_ELEMENT(Break_align_item,before_line_breaking);
  24 SCM
  25 Break_align_item::member_before_line_breaking ()
  26 {
  27   if (break_status_dir() == LEFT)
  28     {
  29       set_elt_property ("self-alignment-X", gh_int2scm (RIGHT));
  30     }
  31   else
  32     {
  33       add_offset_callback (Align_interface::center_on_element, X_AXIS);
  34     }
  35
  36
  37
  38   Real interline= paper_l ()->get_var ("interline");
  39   Link_array<Score_element> elems;
  40   Link_array<Score_element> all_elems
  41     = Pointer_group_interface__extract_elements (this, (Score_element*)0,
  42                                          "elements");
  43
  44   for (int i=0; i < all_elems.size(); i++)
  45     {
  46       Interval y = all_elems[i]->extent(X_AXIS);
  47       if (!y.empty_b())
  48         elems.push (dynamic_cast<Score_element*> (all_elems[i]));
  49     }
  50
  51   if (!elems.size ())
  52     return SCM_UNDEFINED;
  53
  54   SCM symbol_list = SCM_EOL;
  55   Array<Real> dists;
  56   SCM current_origin = ly_symbol2scm ("none");
  57   for (int i=0; i <= elems.size (); i++)
  58     {
  59       Score_element *next_elt  = i < elems.size ()
  60         ? elems[i]
  61         : 0 ;
  62
  63       SCM next_origin;
  64
  65       if (next_elt)
  66         {
  67           next_origin = next_elt->get_elt_property ("break-align-symbol");
  68           next_origin =
  69             (next_origin == SCM_UNDEFINED)
  70             ? ly_symbol2scm ("none")
  71             : next_origin;
  72         }
  73       else
  74         next_origin = ly_symbol2scm ("begin-of-note");
  75
  76       SCM e = scm_assoc (scm_listify (current_origin,
  77                                       next_origin,
  78                                       SCM_UNDEFINED),
  79                          scm_eval (ly_symbol2scm ("space-alist")));
  80
  81       SCM extra_space;
  82       if (e != SCM_BOOL_F)
  83         {
  84           extra_space = gh_cdr (e);
  85         }
  86       else
  87         {
  88           warning (_f ("unknown spacing pair `%s', `%s'",
  89                        ly_symbol2string (current_origin),
  90                        ly_symbol2string (next_origin)));
  91           extra_space = scm_listify (ly_symbol2scm ("minimum-space"), gh_double2scm (0.0), SCM_UNDEFINED);
  92         }
  93
  94       SCM symbol = gh_car  (extra_space);
  95       Real spc = gh_scm2double (gh_cadr(extra_space));
  96       spc *= interline;
  97
  98       dists.push(spc);
  99       symbol_list = gh_cons (symbol, symbol_list);
 100       current_origin = next_origin;
 101     }
 102
 103
 104   // skip the first sym.
 105   symbol_list  = gh_cdr (scm_reverse (symbol_list));
 106   for (int i=0; i <elems.size()-1; i++)
 107     {
 108       String sym_str = ly_symbol2string (gh_car  (symbol_list));
 109       elems[i]->set_elt_property (sym_str,
 110                                   scm_cons (gh_double2scm (0),
 111                                             gh_double2scm (dists[i+1])));
 112
 113       symbol_list = gh_cdr (symbol_list);
 114     }
 115
 116
 117   // urg
 118   SCM first_pair = elems[0]->get_elt_property ("minimum-space");
 119   if (gh_pair_p (first_pair))
 120     first_pair = first_pair;
 121   else
 122     first_pair = gh_cons (gh_double2scm (0.0), gh_double2scm (0.0));
 123
 124   scm_set_car_x (first_pair, gh_double2scm (-dists[0]));
 125   elems[0]->set_elt_property ("minimum-space", first_pair);
 126
 127
 128   /*
 129     Force callbacks for alignment to be called
 130    */
 131   Real unused =  elems[0]->relative_coordinate (this, X_AXIS);
 132   Real pre_space = elems[0]->relative_coordinate (column_l (), X_AXIS);
 133
 134   Real xl = elems[0]->extent (X_AXIS)[LEFT];
 135   if (!isinf (xl))
 136     pre_space += xl;
 137   else
 138     programming_error ("Infinity reached. ");
 139
 140   Real xr = elems.top ()->extent (X_AXIS)[RIGHT];
 141   Real spring_len = elems.top ()->relative_coordinate (column_l (), X_AXIS);
 142   if (!isinf (xr))
 143     spring_len += xr;
 144   else
 145     programming_error ("Infinity reached.");
 146
 147   Real stretch_distance =0.;
 148
 149   if (gh_car  (symbol_list) == ly_symbol2scm ("extra-space"))
 150     {
 151       spring_len += dists.top ();
 152       stretch_distance = dists.top ();
 153     }
 154   else if (gh_car  (symbol_list) == ly_symbol2scm ("minimum-space"))
 155     {
 156       spring_len = spring_len >? dists.top ();
 157       stretch_distance = spring_len;
 158     }
 159
 160   /*
 161     Hint the spacing engine how much space to put in.
 162
 163     The pairs are in the format of an interval (ie. CAR <  CDR).
 164   */
 165   column_l ()->set_elt_property ("extra-space",
 166                                  scm_cons (gh_double2scm (pre_space),
 167                                            gh_double2scm (spring_len)));
 168
 169   column_l ()->set_elt_property ("stretch-distance",
 170                                  gh_cons (gh_double2scm (-dists[0]),
 171                                           gh_double2scm (stretch_distance)));
 172
 173
 174   return SCM_UNDEFINED;
 175 }
 176
 177 Break_align_item::Break_align_item (SCM s)
 178   : Item (s)
 179 {
 180   set_elt_property ("stacking-dir" , gh_int2scm (RIGHT));
 181
 182   Align_interface (this).set_interface ();
 183   Align_interface (this).set_axis (X_AXIS);
 184
 185   add_offset_callback (Side_position_interface::aligned_on_self, X_AXIS);
 186 }