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--2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9 #include "engraver.hh"
  10 #include "protected-scm.hh"
  11 #include "break-align-item.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_l_;
  20   Protected_scm column_alist_;
  21 protected:
  22   virtual void finalize ();
  23   virtual void acknowledge_grob (Grob_info i);
  24   virtual void stop_translation_timestep ();
  25   void add_column (SCM);
  26
  27 public:
  28   VIRTUAL_COPY_CONS (Translator);
  29   Break_align_engraver ();
  30 };
  31
  32
  33
  34 ADD_THIS_TRANSLATOR (Break_align_engraver);
  35
  36 void
  37 Break_align_engraver::add_column (SCM smob)
  38 {
  39   Grob * e = unsmob_grob (smob);
  40   Break_align_interface::add_element (align_l_,e);
  41   typeset_grob (e);
  42 }
  43
  44 void
  45 Break_align_engraver::finalize ()
  46 {
  47   column_alist_ = SCM_EOL;
  48 }
  49
  50 void
  51 Break_align_engraver::stop_translation_timestep ()
  52 {
  53   SCM order = get_property ("breakAlignOrder");
  54   for (; gh_pair_p (order); order = gh_cdr (order))
  55     {
  56       SCM p = scm_assoc (gh_car (order), column_alist_);
  57       if (gh_pair_p (p))
  58         {
  59           add_column (gh_cdr (p));
  60           column_alist_ = scm_assoc_remove_x (column_alist_, gh_car (order));
  61         }
  62     }
  63
  64   for (SCM p = column_alist_; gh_pair_p (p); p = gh_cdr (p))
  65     {
  66       SCM pair = gh_car (p);
  67       add_column (gh_cdr (pair));
  68     }
  69
  70
  71   column_alist_ = SCM_EOL;
  72
  73   if (align_l_)
  74     {
  75       typeset_grob (align_l_);
  76       align_l_ = 0;
  77     }
  78 }
  79
  80
  81 Break_align_engraver::Break_align_engraver ()
  82 {
  83   column_alist_ = SCM_EOL;
  84   align_l_ =0;
  85 }
  86
  87 void
  88 Break_align_engraver::acknowledge_grob (Grob_info inf)
  89 {
  90   if (Item * item_l = dynamic_cast <Item *> (inf.elem_l_))
  91     {
  92       if (item_l->empty_b (X_AXIS) || item_l->parent_l (X_AXIS))
  93         return;
  94
  95       SCM bp=item_l->get_grob_property ("breakable");
  96       bool breakable = (to_boolean (bp));
  97       if (!breakable)
  98         return ;
  99
 100       SCM align_name = item_l->get_grob_property ("break-align-symbol");
 101       if (!gh_symbol_p (align_name))
 102         return ;
 103
 104       if (!align_l_)
 105         {
 106           align_l_ = new Item (get_property ("BreakAlignment"));
 107           Break_align_interface::set_interface (align_l_);
 108           announce_grob (align_l_,0);
 109
 110           SCM edge_sym = ly_symbol2scm ("Left_edge_item");
 111           Item * edge = new Item (get_property ("LeftEdge"));
 112
 113
 114
 115           /*
 116             If the element is empty, it will be ignored in the break
 117             alignment stuff.
 118
 119             TODO: switch off ignoring empty stuff?
 120           */
 121           edge->set_extent_callback (Grob::point_dimension_callback_proc, X_AXIS);
 122
 123           /*
 124             We must have left-edge in the middle.  Instrument-names
 125             are left to left-edge, so they don't enter the staff.
 126           */
 127           align_l_->set_grob_property ("self-alignment-X", edge->self_scm ());
 128
 129           announce_grob (edge, 0);
 130           column_alist_ = scm_assoc_set_x (column_alist_, edge_sym, edge->self_scm ());
 131         }
 132
 133       SCM s = scm_assoc (align_name, column_alist_);
 134
 135       Item * group = 0;
 136
 137       if (s != SCM_BOOL_F)
 138         {
 139           Grob *e =  unsmob_grob (gh_cdr (s));
 140           group = dynamic_cast<Item*> (e);
 141         }
 142       else
 143         {
 144           group = new Item (get_property ("BreakAlignGroup"));
 145
 146           Axis_group_interface::set_interface (group);
 147           Axis_group_interface::set_axes (group, X_AXIS,X_AXIS);
 148
 149           group->set_grob_property ("break-align-symbol", align_name);
 150           group->set_parent (align_l_, Y_AXIS);
 151           announce_grob (group, 0);
 152           column_alist_ = scm_assoc_set_x (column_alist_, align_name, group->self_scm ());
 153
 154         }
 155       Axis_group_interface::add_element (group, item_l);
 156     }
 157 }