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
  38 ADD_ACKNOWLEDGER (Vertical_align_engraver, axis_group);
  39 ADD_TRANSLATOR (Vertical_align_engraver,
  40                 /* doc */
  41                 "Catch groups (staves, lyrics lines, etc.) and stack them"
  42                 " vertically.",
  43
  44                 /* create */
  45                 "VerticalAlignment ",
  46
  47                 /* read */
  48                 "alignAboveContext "
  49                 "alignBelowContext ",
  50
  51                 /* write */
  52                 ""
  53                 );
  54
  55 Vertical_align_engraver::Vertical_align_engraver ()
  56 {
  57   valign_ = 0;
  58   id_to_group_hashtab_ = SCM_EOL;
  59 }
  60
  61 void
  62 Vertical_align_engraver::derived_mark () const
  63 {
  64   scm_gc_mark (id_to_group_hashtab_);
  65 }
  66
  67 void
  68 Vertical_align_engraver::initialize ()
  69 {
  70   id_to_group_hashtab_ = scm_c_make_hash_table (11);
  71 }
  72
  73 void
  74 Vertical_align_engraver::process_music ()
  75 {
  76   if (!valign_)
  77     {
  78       valign_ = make_spanner ("VerticalAlignment", SCM_EOL);
  79       valign_->set_bound (LEFT, unsmob_grob (get_property ("currentCommandColumn")));
  80       Align_interface::set_ordered (valign_);
  81     }
  82 }
  83
  84 void
  85 Vertical_align_engraver::finalize ()
  86 {
  87   if (valign_)
  88     {
  89       valign_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
  90       valign_ = 0;
  91     }
  92 }
  93
  94 bool
  95 Vertical_align_engraver::qualifies (Grob_info i) const
  96 {
  97   int sz = i.origin_contexts ((Translator *)this).size ();
  98
  99   return sz > 0 && Axis_group_interface::has_interface (i.grob ())
 100     && !i.grob ()->get_parent (Y_AXIS)
 101     && !to_boolean (i.grob ()->get_property ("no-alignment"))
 102     && Axis_group_interface::has_axis (i.grob (), Y_AXIS);
 103 }
 104
 105 void
 106 Vertical_align_engraver::acknowledge_axis_group (Grob_info i)
 107 {
 108   if (qualifies (i))
 109     {
 110       string id = i.context ()->id_string ();
 111
 112       scm_hash_set_x (id_to_group_hashtab_, ly_string2scm (id),
 113                       i.grob ()->self_scm ());
 114
 115       SCM before_id = i.context ()->get_property ("alignAboveContext");
 116       SCM after_id = i.context ()->get_property ("alignBelowContext");
 117
 118       SCM before = scm_hash_ref (id_to_group_hashtab_, before_id, SCM_BOOL_F);
 119       SCM after = scm_hash_ref (id_to_group_hashtab_, after_id, SCM_BOOL_F);
 120
 121       Grob *before_grob = unsmob_grob (before);
 122       Grob *after_grob = unsmob_grob (after);
 123
 124       Align_interface::add_element (valign_, i.grob ());
 125
 126       if (before_grob || after_grob)
 127         {
 128           Grob_array *ga = unsmob_grob_array (valign_->get_object ("elements"));
 129           vector<Grob*> &arr = ga->array_reference ();
 130
 131           Grob *added = arr.back ();
 132           arr.pop_back ();
 133           for (vsize i = 0; i < arr.size (); i++)
 134             {
 135               if (arr[i] == before_grob)
 136                 {
 137                   arr.insert (arr.begin () + i, added);
 138                   break;
 139                 }
 140               else if (arr[i] == after_grob)
 141                 {
 142                   arr.insert (arr.begin () + i + 1, added);
 143                   break;
 144                 }
 145             }
 146         }
 147     }
 148 }