lily/break-align-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1999--2011 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19 #include "engraver.hh"
  20 #include "protected-scm.hh"
  21 #include "break-align-interface.hh"
  22 #include "align-interface.hh"
  23 #include "axis-group-interface.hh"
  24 #include "context.hh"
  25 #include "translator-group.hh"
  26 #include "item.hh"
  27
  28 #include "translator.icc"
  29
  30 class Break_align_engraver : public Engraver
  31 {
  32   Item *align_;
  33   SCM column_alist_;
  34   Item *left_edge_;
  35
  36   void add_to_group (SCM, Item *);
  37   void create_alignment (Grob_info);
  38 protected:
  39   void stop_translation_timestep ();
  40   virtual void derived_mark () const;
  41 public:
  42   TRANSLATOR_DECLARATIONS (Break_align_engraver);
  43   DECLARE_ACKNOWLEDGER (break_aligned);
  44   DECLARE_ACKNOWLEDGER (break_alignable);
  45 };
  46
  47 void
  48 Break_align_engraver::stop_translation_timestep ()
  49 {
  50   column_alist_ = SCM_EOL;
  51
  52   align_ = 0;
  53   left_edge_ = 0;
  54 }
  55
  56 Break_align_engraver::Break_align_engraver ()
  57 {
  58   column_alist_ = SCM_EOL;
  59   left_edge_ = 0;
  60   align_ = 0;
  61 }
  62
  63 void
  64 Break_align_engraver::derived_mark () const
  65 {
  66   scm_gc_mark (column_alist_);
  67 }
  68
  69 void
  70 Break_align_engraver::acknowledge_break_alignable (Grob_info inf)
  71 {
  72   if (!align_)
  73     create_alignment (inf);
  74
  75   Grob *g = inf.grob ();
  76
  77   if (!g->get_parent (X_AXIS))
  78     g->set_parent (align_, X_AXIS);
  79 }
  80
  81 void
  82 Break_align_engraver::acknowledge_break_aligned (Grob_info inf)
  83 {
  84   if (Item *item = dynamic_cast<Item *> (inf.grob ()))
  85     {
  86       /*
  87         Removed check for item->empty (X_AXIS). --hwn 20/1/04
  88       */
  89       if (item->get_parent (X_AXIS))
  90         return;
  91
  92       if (!Item::is_non_musical (item))
  93         return;
  94
  95       SCM align_name = item->get_property ("break-align-symbol");
  96       if (!scm_is_symbol (align_name))
  97         return;
  98
  99       if (!align_)
 100         create_alignment (inf);
 101
 102       add_to_group (align_name, item);
 103     }
 104 }
 105
 106 void
 107 Break_align_engraver::create_alignment (Grob_info inf)
 108 {
 109   align_ = make_item ("BreakAlignment", SCM_EOL);
 110
 111   Context *origin = inf.origin_contexts (this)[0];
 112
 113   Translator_group *tg = origin->implementation ();
 114   Engraver *random_source = dynamic_cast<Engraver *> (unsmob_translator (scm_car (tg->get_simple_trans_list ())));
 115   if (!random_source)
 116     random_source = this;
 117
 118   /*
 119     Make left edge appear to come from same context as clef/bar-line etc.
 120   */
 121   left_edge_ = random_source->make_item ("LeftEdge", SCM_EOL);
 122   add_to_group (left_edge_->get_property ("break-align-symbol"),
 123                 left_edge_);
 124 }
 125
 126 void
 127 Break_align_engraver::add_to_group (SCM align_name, Item *item)
 128 {
 129   SCM s = scm_assoc (align_name, column_alist_);
 130   Item *group = 0;
 131
 132   if (s != SCM_BOOL_F)
 133     {
 134       Grob *e = unsmob_grob (scm_cdr (s));
 135       group = dynamic_cast<Item *> (e);
 136     }
 137   else
 138     {
 139       group = make_item ("BreakAlignGroup", item->self_scm ());
 140
 141       group->set_property ("break-align-symbol", align_name);
 142       group->set_parent (align_, Y_AXIS);
 143
 144       column_alist_ = scm_assoc_set_x (column_alist_, align_name, group->self_scm ());
 145
 146       Break_alignment_interface::add_element (align_, group);
 147     }
 148   Axis_group_interface::add_element (group, item);
 149 }
 150
 151 ADD_ACKNOWLEDGER (Break_align_engraver, break_aligned);
 152 ADD_ACKNOWLEDGER (Break_align_engraver, break_alignable);
 153 ADD_TRANSLATOR (Break_align_engraver,
 154                 /* doc */
 155                 "Align grobs with corresponding @code{break-align-symbols}"
 156                 " into groups, and order the groups according to"
 157                 " @code{breakAlignOrder}.  The left edge of the alignment gets"
 158                 " a separate group, with a symbol @code{left-edge}.",
 159
 160                 /* create */
 161                 "BreakAlignment "
 162                 "BreakAlignGroup "
 163                 "LeftEdge ",
 164
 165                 /* read */
 166                 "",
 167
 168                 /* write */
 169                 ""
 170                 );