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--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9 #include "engraver.hh"
  10 #include "protected-scm.hh"
  11 #include "break-align-interface.hh"
  12 #include "item.hh"
  13 #include "align-interface.hh"
  14 #include "axis-group-interface.hh"
  15
  16
  17 class Break_align_engraver : public Engraver
  18 {
  19   Item *align_;
  20   Protected_scm column_alist_;
  21   Item *edge_;
  22
  23   void add_to_group (SCM,Item*);
  24 protected:
  25   virtual void finalize ();
  26   virtual void acknowledge_grob (Grob_info i);
  27   virtual void stop_translation_timestep ();
  28   void add_column (SCM);
  29
  30 public:
  31   TRANSLATOR_DECLARATIONS(Break_align_engraver);
  32 };
  33
  34 void
  35 Break_align_engraver::add_column (SCM smob)
  36 {
  37   Grob * e = unsmob_grob (smob);
  38   Break_align_interface::add_element (align_,e);
  39   typeset_grob (e);
  40 }
  41
  42 void
  43 Break_align_engraver::finalize ()
  44 {
  45   column_alist_ = SCM_EOL;
  46 }
  47
  48 void
  49 Break_align_engraver::stop_translation_timestep ()
  50 {
  51   SCM order = get_property ("breakAlignOrder");
  52   for (; gh_pair_p (order); order = ly_cdr (order))
  53     {
  54       SCM p = scm_assoc (ly_car (order), column_alist_);
  55       if (gh_pair_p (p))
  56         {
  57           add_column (ly_cdr (p));
  58           column_alist_ = scm_assoc_remove_x (column_alist_, ly_car (order));
  59         }
  60     }
  61
  62   for (SCM p = column_alist_; gh_pair_p (p); p = ly_cdr (p))
  63     {
  64       SCM pair = ly_car (p);
  65       add_column (ly_cdr (pair));
  66     }
  67
  68
  69   column_alist_ = SCM_EOL;
  70
  71   if (align_)
  72     {
  73       typeset_grob (align_);
  74       align_ = 0;
  75     }
  76   if (edge_)
  77     {
  78       typeset_grob (edge_);
  79       edge_ = 0;
  80     }
  81 }
  82
  83
  84 Break_align_engraver::Break_align_engraver ()
  85 {
  86   column_alist_ = SCM_EOL;
  87   edge_ = 0;
  88   align_ = 0;
  89 }
  90
  91 void
  92 Break_align_engraver::acknowledge_grob (Grob_info inf)
  93 {
  94   if (Item * item = dynamic_cast <Item *> (inf.grob_))
  95     {
  96       if (item->empty_b (X_AXIS) || item->get_parent (X_AXIS))
  97         return;
  98
  99       SCM bp=item->get_grob_property ("breakable");
 100       bool breakable = (to_boolean (bp));
 101       if (!breakable)
 102         return ;
 103
 104       SCM align_name = item->get_grob_property ("break-align-symbol");
 105       if (!gh_symbol_p (align_name))
 106         return ;
 107
 108       if (!align_)
 109         {
 110           align_ = new Item (get_property ("BreakAlignment"));
 111
 112           announce_grob (align_, SCM_EOL);
 113
 114           edge_ = new Item (get_property ("LeftEdge"));
 115           add_to_group (edge_->get_grob_property ("break-align-symbol"), edge_);
 116           announce_grob(edge_, SCM_EOL);
 117         }
 118
 119       add_to_group (align_name, item);
 120     }
 121 }
 122
 123 void
 124 Break_align_engraver::add_to_group(SCM align_name, Item*item)
 125 {
 126   SCM s = scm_assoc (align_name, column_alist_);
 127   Item * group = 0;
 128
 129   if (s != SCM_BOOL_F)
 130     {
 131       Grob *e =  unsmob_grob (ly_cdr (s));
 132       group = dynamic_cast<Item*> (e);
 133     }
 134   else
 135     {
 136       group = new Item (get_property ("BreakAlignGroup"));
 137
 138       group->set_grob_property ("break-align-symbol", align_name);
 139       group->set_parent (align_, Y_AXIS);
 140       announce_grob(group, item->self_scm());
 141
 142       column_alist_ = scm_assoc_set_x (column_alist_, align_name, group->self_scm ());
 143
 144     }
 145   Axis_group_interface::add_element (group, item);
 146 }
 147
 148 ENTER_DESCRIPTION(Break_align_engraver,
 149 /* descr */       "Align grobs with corresponding break-align-symbols into groups, and order the groups according to breakAlignOrder",
 150 /* creats*/       "BreakAlignment BreakAlignGroup LeftEdge",
 151 /* accepts */     "",
 152 /* acks  */       "break-aligned-interface"
 153 ,/* reads */       "breakAlignOrder",
 154 /* write */       "");