lily/vertical-align-engraver.cc

   1 /*
   2   vertical-align-engraver.cc -- implement Vertical_align_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "context.hh"
  10 #include "paper-column.hh"
  11 #include "align-interface.hh"
  12 #include "span-bar.hh"
  13 #include "axis-group-interface.hh"
  14 #include "engraver.hh"
  15 #include "spanner.hh"
  16 #include "pointer-group-interface.hh"
  17 #include "grob-array.hh"
  18
  19 #include "translator.icc"
  20
  21 class Vertical_align_engraver : public Engraver
  22 {
  23   Spanner *valign_;
  24   bool qualifies (Grob_info) const;
  25   SCM id_to_group_hashtab_;
  26
  27 public:
  28   TRANSLATOR_DECLARATIONS (Vertical_align_engraver);
  29   DECLARE_ACKNOWLEDGER (axis_group);
  30
  31 protected:
  32   virtual void derived_mark () const;
  33   void process_music ();
  34   virtual void finalize ();
  35   virtual void initialize ();
  36
  37   bool top_level_;
  38 };
  39
  40 ADD_ACKNOWLEDGER (Vertical_align_engraver, axis_group);
  41 ADD_TRANSLATOR (Vertical_align_engraver,
  42                 /* doc */
  43                 "Catch groups (staves, lyrics lines, etc.) and stack them"
  44                 " vertically.",
  45
  46                 /* create */
  47                 "VerticalAlignment ",
  48
  49                 /* read */
  50                 "alignAboveContext "
  51                 "alignBelowContext ",
  52
  53                 /* write */
  54                 ""
  55                 );
  56
  57 Vertical_align_engraver::Vertical_align_engraver ()
  58 {
  59   valign_ = 0;
  60   id_to_group_hashtab_ = SCM_EOL;
  61   top_level_ = false;
  62 }
  63
  64 void
  65 Vertical_align_engraver::derived_mark () const
  66 {
  67   scm_gc_mark (id_to_group_hashtab_);
  68 }
  69
  70 void
  71 Vertical_align_engraver::initialize ()
  72 {
  73   id_to_group_hashtab_ = scm_c_make_hash_table (11);
  74 }
  75
  76 void
  77 Vertical_align_engraver::process_music ()
  78 {
  79   if (!valign_)
  80     {
  81       top_level_ = to_boolean (get_property ("topLevelAlignment"));
  82
  83       valign_ = make_spanner (top_level_ ? "VerticalAlignment" : "StaffGrouper", SCM_EOL);
  84       valign_->set_bound (LEFT, unsmob_grob (get_property ("currentCommandColumn")));
  85       Align_interface::set_ordered (valign_);
  86     }
  87 }
  88
  89 void
  90 Vertical_align_engraver::finalize ()
  91 {
  92   if (valign_)
  93     {
  94       valign_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
  95       valign_ = 0;
  96     }
  97 }
  98
  99 bool
 100 Vertical_align_engraver::qualifies (Grob_info i) const
 101 {
 102   int sz = i.origin_contexts ((Translator *)this).size ();
 103
 104   return sz > 0 && Axis_group_interface::has_interface (i.grob ())
 105     && !i.grob ()->get_parent (Y_AXIS)
 106     && !to_boolean (i.grob ()->get_property ("no-alignment"))
 107     && Axis_group_interface::has_axis (i.grob (), Y_AXIS);
 108 }
 109
 110 void
 111 Vertical_align_engraver::acknowledge_axis_group (Grob_info i)
 112 {
 113   if (top_level_ && qualifies (i))
 114     {
 115       string id = i.context ()->id_string ();
 116
 117       scm_hash_set_x (id_to_group_hashtab_, ly_string2scm (id),
 118                       i.grob ()->self_scm ());
 119
 120       SCM before_id = i.context ()->get_property ("alignAboveContext");
 121       SCM after_id = i.context ()->get_property ("alignBelowContext");
 122
 123       SCM before = scm_hash_ref (id_to_group_hashtab_, before_id, SCM_BOOL_F);
 124       SCM after = scm_hash_ref (id_to_group_hashtab_, after_id, SCM_BOOL_F);
 125
 126       Grob *before_grob = unsmob_grob (before);
 127       Grob *after_grob = unsmob_grob (after);
 128
 129       Align_interface::add_element (valign_, i.grob ());
 130
 131       if (before_grob || after_grob)
 132         {
 133           Grob_array *ga = unsmob_grob_array (valign_->get_object ("elements"));
 134           vector<Grob*> &arr = ga->array_reference ();
 135
 136           Grob *added = arr.back ();
 137           arr.pop_back ();
 138           for (vsize i = 0; i < arr.size (); i++)
 139             {
 140               if (arr[i] == before_grob)
 141                 {
 142                   arr.insert (arr.begin () + i, added);
 143                   added->set_property ("staff-affinity", scm_from_int (DOWN));
 144                   break;
 145                 }
 146               else if (arr[i] == after_grob)
 147                 {
 148                   arr.insert (arr.begin () + i + 1, added);
 149                   added->set_property ("staff-affinity", scm_from_int (UP));
 150                   break;
 151                 }
 152             }
 153         }
 154     }
 155   else if (!top_level_)
 156     {
 157       Pointer_group_interface::add_grob (valign_, ly_symbol2scm ("elements"), i.grob ());
 158       i.grob ()->set_object ("staff-grouper", valign_->self_scm ());
 159     }
 160 }