lily/break-align-engraver.cc

   1 /*
   2   break-align-engraver.cc -- implement Break_align_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1999--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8 #include "engraver.hh"
   9 #include "protected-scm.hh"
  10 #include "break-align-interface.hh"
  11 #include "align-interface.hh"
  12 #include "axis-group-interface.hh"
  13 #include "context.hh"
  14 #include "translator-group.hh"
  15
  16 #include "translator.icc"
  17
  18 class Break_align_engraver : public Engraver
  19 {
  20   Item *align_;
  21   SCM column_alist_;
  22   Item *left_edge_;
  23
  24   void add_to_group (SCM, Item *);
  25 protected:
  26   void stop_translation_timestep ();
  27   virtual void derived_mark () const;
  28 public:
  29   TRANSLATOR_DECLARATIONS (Break_align_engraver);
  30   DECLARE_ACKNOWLEDGER (break_aligned);
  31 };
  32
  33 void
  34 Break_align_engraver::stop_translation_timestep ()
  35 {
  36   column_alist_ = SCM_EOL;
  37
  38   align_ = 0;
  39   left_edge_ = 0;
  40 }
  41
  42 Break_align_engraver::Break_align_engraver ()
  43 {
  44   column_alist_ = SCM_EOL;
  45   left_edge_ = 0;
  46   align_ = 0;
  47 }
  48
  49 void
  50 Break_align_engraver::derived_mark () const
  51 {
  52   scm_gc_mark (column_alist_);
  53 }
  54
  55 void
  56 Break_align_engraver::acknowledge_break_aligned (Grob_info inf)
  57 {
  58   if (Item *item = dynamic_cast<Item *> (inf.grob ()))
  59     {
  60       /*
  61         Removed check for item->empty (X_AXIS). --hwn 20/1/04
  62       */
  63       if (item->get_parent (X_AXIS))
  64         return;
  65
  66       if (!Item::is_non_musical (item))
  67         return;
  68
  69       SCM align_name = item->get_property ("break-align-symbol");
  70       if (!scm_is_symbol (align_name))
  71         return;
  72
  73       if (!align_)
  74         {
  75           align_ = make_item ("BreakAlignment", SCM_EOL);
  76
  77           Context *origin = inf.origin_contexts (this)[0];
  78
  79           Translator_group *tg = origin->implementation ();
  80           Engraver *random_source = dynamic_cast<Engraver *> (unsmob_translator (scm_car (tg->get_simple_trans_list ())));
  81
  82           /*
  83             Make left edge appear to come from same context as clef/bar-line etc.
  84           */
  85           left_edge_ = random_source->make_item ("LeftEdge", SCM_EOL);
  86           add_to_group (left_edge_->get_property ("break-align-symbol"),
  87                         left_edge_);
  88         }
  89
  90       add_to_group (align_name, item);
  91     }
  92 }
  93
  94 void
  95 Break_align_engraver::add_to_group (SCM align_name, Item *item)
  96 {
  97   SCM s = scm_assoc (align_name, column_alist_);
  98   Item *group = 0;
  99
 100   if (s != SCM_BOOL_F)
 101     {
 102       Grob *e = unsmob_grob (scm_cdr (s));
 103       group = dynamic_cast<Item *> (e);
 104     }
 105   else
 106     {
 107       group = make_item ("BreakAlignGroup", item->self_scm ());
 108
 109       group->set_property ("break-align-symbol", align_name);
 110       group->set_parent (align_, Y_AXIS);
 111
 112       column_alist_ = scm_assoc_set_x (column_alist_, align_name, group->self_scm ());
 113
 114       Break_align_interface::add_element (align_, group);
 115     }
 116   Axis_group_interface::add_element (group, item);
 117 }
 118 ADD_ACKNOWLEDGER (Break_align_engraver, break_aligned);
 119 ADD_TRANSLATOR (Break_align_engraver,
 120                 "Align grobs with corresponding @code{break-align-symbols} into "
 121                 "groups, and order the groups according to @code{breakAlignOrder}. "
 122                 "The left edge of the alignment gets a separate group, with a symbol @code{left-edge}. ",
 123                 /* create */ "BreakAlignment BreakAlignGroup LeftEdge",
 124                 /* accept */ "",
 125                 /* read */ "",
 126                 /* write */ "");