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--2009 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   void create_alignment (Grob_info);
  27 protected:
  28   void stop_translation_timestep ();
  29   virtual void derived_mark () const;
  30 public:
  31   TRANSLATOR_DECLARATIONS (Break_align_engraver);
  32   DECLARE_ACKNOWLEDGER (break_aligned);
  33   DECLARE_ACKNOWLEDGER (break_alignable);
  34 };
  35
  36 void
  37 Break_align_engraver::stop_translation_timestep ()
  38 {
  39   column_alist_ = SCM_EOL;
  40
  41   align_ = 0;
  42   left_edge_ = 0;
  43 }
  44
  45 Break_align_engraver::Break_align_engraver ()
  46 {
  47   column_alist_ = SCM_EOL;
  48   left_edge_ = 0;
  49   align_ = 0;
  50 }
  51
  52 void
  53 Break_align_engraver::derived_mark () const
  54 {
  55   scm_gc_mark (column_alist_);
  56 }
  57
  58 void
  59 Break_align_engraver::acknowledge_break_alignable (Grob_info inf)
  60 {
  61   if (!align_)
  62     create_alignment (inf);
  63
  64   Grob *g = inf.grob ();
  65
  66   if (!g->get_parent (X_AXIS))
  67     g->set_parent (align_, X_AXIS);
  68 }
  69
  70 void
  71 Break_align_engraver::acknowledge_break_aligned (Grob_info inf)
  72 {
  73   if (Item *item = dynamic_cast<Item *> (inf.grob ()))
  74     {
  75       /*
  76         Removed check for item->empty (X_AXIS). --hwn 20/1/04
  77       */
  78       if (item->get_parent (X_AXIS))
  79         return;
  80
  81       if (!Item::is_non_musical (item))
  82         return;
  83
  84       SCM align_name = item->get_property ("break-align-symbol");
  85       if (!scm_is_symbol (align_name))
  86         return;
  87
  88       if (!align_)
  89         create_alignment (inf);
  90
  91       add_to_group (align_name, item);
  92     }
  93 }
  94
  95 void
  96 Break_align_engraver::create_alignment (Grob_info inf)
  97 {
  98   align_ = make_item ("BreakAlignment", SCM_EOL);
  99
 100   Context *origin = inf.origin_contexts (this)[0];
 101
 102   Translator_group *tg = origin->implementation ();
 103   Engraver *random_source = dynamic_cast<Engraver *> (unsmob_translator (scm_car (tg->get_simple_trans_list ())));
 104   if (!random_source)
 105     random_source = this;
 106
 107   /*
 108     Make left edge appear to come from same context as clef/bar-line etc.
 109   */
 110   left_edge_ = random_source->make_item ("LeftEdge", SCM_EOL);
 111   add_to_group (left_edge_->get_property ("break-align-symbol"),
 112                 left_edge_);
 113 }
 114
 115 void
 116 Break_align_engraver::add_to_group (SCM align_name, Item *item)
 117 {
 118   SCM s = scm_assoc (align_name, column_alist_);
 119   Item *group = 0;
 120
 121   if (s != SCM_BOOL_F)
 122     {
 123       Grob *e = unsmob_grob (scm_cdr (s));
 124       group = dynamic_cast<Item *> (e);
 125     }
 126   else
 127     {
 128       group = make_item ("BreakAlignGroup", item->self_scm ());
 129
 130       group->set_property ("break-align-symbol", align_name);
 131       group->set_parent (align_, Y_AXIS);
 132
 133       column_alist_ = scm_assoc_set_x (column_alist_, align_name, group->self_scm ());
 134
 135       Break_alignment_interface::add_element (align_, group);
 136     }
 137   Axis_group_interface::add_element (group, item);
 138 }
 139
 140 ADD_ACKNOWLEDGER (Break_align_engraver, break_aligned);
 141 ADD_ACKNOWLEDGER (Break_align_engraver, break_alignable);
 142 ADD_TRANSLATOR (Break_align_engraver,
 143                 /* doc */
 144                 "Align grobs with corresponding @code{break-align-symbols}"
 145                 " into groups, and order the groups according to"
 146                 " @code{breakAlignOrder}.  The left edge of the alignment gets"
 147                 " a separate group, with a symbol @code{left-edge}.",
 148
 149                 /* create */
 150                 "BreakAlignment "
 151                 "BreakAlignGroup "
 152                 "LeftEdge ",
 153
 154                 /* read */
 155                 "",
 156
 157                 /* write */
 158                 ""
 159                 );