lily/include/translator.hh

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2009 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
  20 #ifndef TRANSLATOR_HH
  21 #define TRANSLATOR_HH
  22
  23 #include "global-ctor.hh"
  24 #include "lily-proto.hh"
  25 #include "virtual-methods.hh"
  26 #include "input.hh"             // for error reporting
  27 #include "smobs.hh"
  28 #include "std-vector.hh"
  29 #include "protected-scm.hh"
  30
  31 struct Acknowledge_information
  32 {
  33   SCM symbol_;
  34   Engraver_void_function_engraver_grob_info function_;
  35 };
  36
  37
  38 /*
  39   Each translator class has a static list of listener records. Each
  40   record makes one explains how to register one of the class's stream event
  41   listeners to a context.
  42 */
  43 typedef struct translator_listener_record {
  44   Listener (*get_listener_) (void *);
  45   SCM event_class_;
  46   struct translator_listener_record *next_;
  47 } translator_listener_record;
  48
  49 #define TRANSLATOR_DECLARATIONS(NAME)                                   \
  50 private:                                                                \
  51   static translator_listener_record *listener_list_;                    \
  52   public:                                                               \
  53   NAME ();                                                              \
  54   VIRTUAL_COPY_CONSTRUCTOR (Translator, NAME);                          \
  55   static SCM static_description_;                                       \
  56   static Drul_array<vector<Acknowledge_information> > acknowledge_static_array_drul_; \
  57   virtual void fetch_precomputable_methods (Translator_void_method_ptr methods[]); \
  58   virtual SCM static_translator_description () const;                   \
  59   virtual SCM translator_description () const;                          \
  60   virtual Engraver_void_function_engraver_grob_info get_acknowledger (SCM sym) \
  61   {                                                                     \
  62     return static_get_acknowledger (sym);                               \
  63   }                                                                     \
  64   virtual Engraver_void_function_engraver_grob_info get_end_acknowledger (SCM sym) \
  65   {                                                                     \
  66     return static_get_end_acknowledger (sym);                           \
  67   } \
  68   static Engraver_void_function_engraver_grob_info static_get_acknowledger (SCM sym); \
  69   static Engraver_void_function_engraver_grob_info static_get_end_acknowledger(SCM); \
  70 public:                                                                 \
  71   virtual translator_listener_record *get_listener_list () const        \
  72   {                                                                     \
  73     return listener_list_;                                              \
  74   }                                                                     \
  75   /* end #define */
  76
  77 #define DECLARE_TRANSLATOR_LISTENER(m)                  \
  78 public:                                                 \
  79 inline void listen_ ## m (Stream_event *);              \
  80 /* Should be private */                                 \
  81 static void _internal_declare_ ## m ();                 \
  82 private:                                                \
  83 static Listener _get_ ## m ## _listener (void *);       \
  84 DECLARE_LISTENER (_listen_scm_ ## m);
  85
  86 #define DECLARE_ACKNOWLEDGER(x) public : void acknowledge_ ## x (Grob_info); protected:
  87 #define DECLARE_END_ACKNOWLEDGER(x) public : void acknowledge_end_ ## x (Grob_info); protected:
  88
  89 enum Translator_precompute_index
  90   {
  91     START_TRANSLATION_TIMESTEP,
  92     STOP_TRANSLATION_TIMESTEP,
  93     PROCESS_MUSIC,
  94     PROCESS_ACKNOWLEDGED,
  95     TRANSLATOR_METHOD_PRECOMPUTE_COUNT,
  96   };
  97
  98 /*
  99   Translate music into grobs.
 100 */
 101 class Translator
 102 {
 103   void init ();
 104
 105 protected:
 106   bool must_be_last_;
 107
 108 public:
 109   bool must_be_last () const;
 110
 111   Context *context () const { return daddy_context_; }
 112
 113   Translator (Translator const &);
 114
 115   SCM internal_get_property (SCM symbol) const;
 116
 117   virtual Output_def *get_output_def () const;
 118   virtual Translator_group *get_daddy_translator ()const;
 119   virtual Moment now_mom () const;
 120
 121   virtual void initialize ();
 122   virtual void finalize ();
 123
 124   /*should maybe be virtual*/
 125   void connect_to_context (Context *c);
 126   void disconnect_from_context (Context *c);
 127
 128   void stop_translation_timestep ();
 129   void start_translation_timestep ();
 130   void process_music ();
 131   void process_acknowledged ();
 132
 133   Context *get_score_context () const;
 134   Global_context *get_global_context () const;
 135
 136   TRANSLATOR_DECLARATIONS (Translator);
 137   DECLARE_SMOBS (Translator);
 138
 139 protected:                      // should be private.
 140   Context *daddy_context_;
 141   void protect_event (SCM ev);
 142   virtual void derived_mark () const;
 143   static void add_translator_listener (translator_listener_record **listener_list, translator_listener_record *r, Listener (*get_listener) (void *), const char *ev_class);
 144   SCM static_translator_description (const char *grobs,
 145                                      const char *desc,
 146                                      translator_listener_record *listener_list,
 147                                      const char *read,
 148                                      const char *write) const;
 149
 150   friend class Translator_group;
 151 };
 152 void add_translator (Translator *trans);
 153
 154 Translator *get_translator (SCM s);
 155 Moment get_event_length (Stream_event *s, Moment now);
 156 Moment get_event_length (Stream_event *s);
 157 DECLARE_UNSMOB (Translator, translator);
 158
 159
 160 /*
 161   This helper is only meaningful inside listen_* methods.
 162 */
 163 extern bool internal_event_assignment (Stream_event **old_ev, Stream_event *new_ev, const char *function);
 164 #define ASSIGN_EVENT_ONCE(o,n) internal_event_assignment (&o, n, __FUNCTION__)
 165
 166
 167 #endif // TRANSLATOR_HH