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--2007 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 #include "item.hh"
  16
  17 #include "translator.icc"
  18
  19 class Break_align_engraver : public Engraver
  20 {
  21   Item *align_;
  22   SCM column_alist_;
  23   Item *left_edge_;
  24
  25   void add_to_group (SCM, Item *);
  26 protected:
  27   void stop_translation_timestep ();
  28   virtual void derived_mark () const;
  29 public:
  30   TRANSLATOR_DECLARATIONS (Break_align_engraver);
  31   DECLARE_ACKNOWLEDGER (break_aligned);
  32 };
  33
  34 void
  35 Break_align_engraver::stop_translation_timestep ()
  36 {
  37   column_alist_ = SCM_EOL;
  38
  39   align_ = 0;
  40   left_edge_ = 0;
  41 }
  42
  43 Break_align_engraver::Break_align_engraver ()
  44 {
  45   column_alist_ = SCM_EOL;
  46   left_edge_ = 0;
  47   align_ = 0;
  48 }
  49
  50 void
  51 Break_align_engraver::derived_mark () const
  52 {
  53   scm_gc_mark (column_alist_);
  54 }
  55
  56 void
  57 Break_align_engraver::acknowledge_break_aligned (Grob_info inf)
  58 {
  59   if (Item *item = dynamic_cast<Item *> (inf.grob ()))
  60     {
  61       /*
  62         Removed check for item->empty (X_AXIS). --hwn 20/1/04
  63       */
  64       if (item->get_parent (X_AXIS))
  65         return;
  66
  67       if (!Item::is_non_musical (item))
  68         return;
  69
  70       SCM align_name = item->get_property ("break-align-symbol");
  71       if (!scm_is_symbol (align_name))
  72         return;
  73
  74       if (!align_)
  75         {
  76           align_ = make_item ("BreakAlignment", SCM_EOL);
  77
  78           Context *origin = inf.origin_contexts (this)[0];
  79
  80           Translator_group *tg = origin->implementation ();
  81           Engraver *random_source = dynamic_cast<Engraver *> (unsmob_translator (scm_car (tg->get_simple_trans_list ())));
  82
  83           /*
  84             Make left edge appear to come from same context as clef/bar-line etc.
  85           */
  86           left_edge_ = random_source->make_item ("LeftEdge", SCM_EOL);
  87           add_to_group (left_edge_->get_property ("break-align-symbol"),
  88                         left_edge_);
  89         }
  90
  91       add_to_group (align_name, item);
  92     }
  93 }
  94
  95 void
  96 Break_align_engraver::add_to_group (SCM align_name, Item *item)
  97 {
  98   SCM s = scm_assoc (align_name, column_alist_);
  99   Item *group = 0;
 100
 101   if (s != SCM_BOOL_F)
 102     {
 103       Grob *e = unsmob_grob (scm_cdr (s));
 104       group = dynamic_cast<Item *> (e);
 105     }
 106   else
 107     {
 108       group = make_item ("BreakAlignGroup", item->self_scm ());
 109
 110       group->set_property ("break-align-symbol", align_name);
 111       group->set_parent (align_, Y_AXIS);
 112
 113       column_alist_ = scm_assoc_set_x (column_alist_, align_name, group->self_scm ());
 114
 115       Break_alignment_interface::add_element (align_, group);
 116     }
 117   Axis_group_interface::add_element (group, item);
 118 }
 119 ADD_ACKNOWLEDGER (Break_align_engraver, break_aligned);
 120 ADD_TRANSLATOR (Break_align_engraver,
 121                 "Align grobs with corresponding @code{break-align-symbols} into "
 122                 "groups, and order the groups according to @code{breakAlignOrder}. "
 123                 "The left edge of the alignment gets a separate group, with a symbol @code{left-edge}. ",
 124                 /* create */ "BreakAlignment "
 125                 "BreakAlignGroup "
 126                 "LeftEdge ",
 127                 /* read */ "",
 128                 /* write */ "");