lily/include/translator.hh

   1 /*
   2   translator.hh -- declare Translator
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #ifndef TRANSLATOR_HH
  10 #define TRANSLATOR_HH
  11
  12 #include "global-ctor.hh"
  13 #include "lily-proto.hh"
  14 #include "virtual-methods.hh"
  15 #include "input.hh"             // for error reporting
  16 #include "smobs.hh"
  17 #include "std-vector.hh"
  18 #include "protected-scm.hh"
  19
  20 struct Acknowledge_information
  21 {
  22   SCM symbol_;
  23   Engraver_void_function_engraver_grob_info function_;
  24 };
  25
  26
  27 /*
  28   Each translator class has a static list of listener records. Each
  29   record makes one explains how to register one of the class's stream event
  30   listeners to a context.
  31 */
  32 typedef struct translator_listener_record {
  33   Listener (*get_listener_) (void *);
  34   SCM event_class_;
  35   struct translator_listener_record *next_;
  36 } translator_listener_record;
  37
  38 #define TRANSLATOR_DECLARATIONS(NAME)                                   \
  39 private:                                                                \
  40   static translator_listener_record *listener_list_;                    \
  41   public:                                                               \
  42   NAME ();                                                              \
  43   VIRTUAL_COPY_CONSTRUCTOR (Translator, NAME);                          \
  44   static SCM static_description_;                                       \
  45   static Drul_array<vector<Acknowledge_information> > acknowledge_static_array_drul_; \
  46   virtual void fetch_precomputable_methods (Translator_void_method_ptr methods[]); \
  47   virtual SCM static_translator_description () const;                   \
  48   virtual SCM translator_description () const;                          \
  49   virtual Engraver_void_function_engraver_grob_info get_acknowledger (SCM sym) \
  50   {                                                                     \
  51     return static_get_acknowledger (sym);                               \
  52   }                                                                     \
  53   virtual Engraver_void_function_engraver_grob_info get_end_acknowledger (SCM sym) \
  54   {                                                                     \
  55     return static_get_end_acknowledger (sym);                           \
  56   } \
  57   static Engraver_void_function_engraver_grob_info static_get_acknowledger (SCM sym); \
  58   static Engraver_void_function_engraver_grob_info static_get_end_acknowledger(SCM); \
  59 public:                                                                 \
  60   virtual translator_listener_record *get_listener_list () const        \
  61   {                                                                     \
  62     return listener_list_;                                              \
  63   }                                                                     \
  64   /* end #define */
  65
  66 #define DECLARE_TRANSLATOR_LISTENER(m)                  \
  67 public:                                                 \
  68 inline void listen_ ## m (Stream_event *);              \
  69 /* Should be private */                                 \
  70 static void _internal_declare_ ## m ();                 \
  71 private:                                                \
  72 static Listener _get_ ## m ## _listener (void *);       \
  73 DECLARE_LISTENER (_listen_scm_ ## m);
  74
  75 #define DECLARE_ACKNOWLEDGER(x) public : void acknowledge_ ## x (Grob_info); protected:
  76 #define DECLARE_END_ACKNOWLEDGER(x) public : void acknowledge_end_ ## x (Grob_info); protected:
  77
  78 enum Translator_precompute_index
  79   {
  80     START_TRANSLATION_TIMESTEP,
  81     STOP_TRANSLATION_TIMESTEP,
  82     PROCESS_MUSIC,
  83     PROCESS_ACKNOWLEDGED,
  84     TRANSLATOR_METHOD_PRECOMPUTE_COUNT,
  85   };
  86
  87 /*
  88   Translate music into grobs.
  89 */
  90 class Translator
  91 {
  92   void init ();
  93
  94 protected:
  95   bool must_be_last_;
  96
  97 public:
  98   bool must_be_last () const;
  99
 100   Context *context () const { return daddy_context_; }
 101
 102   Translator (Translator const &);
 103
 104   SCM internal_get_property (SCM symbol) const;
 105
 106   virtual Output_def *get_output_def () const;
 107   virtual Translator_group *get_daddy_translator ()const;
 108   virtual Moment now_mom () const;
 109
 110   virtual void initialize ();
 111   virtual void finalize ();
 112
 113   /*should maybe be virtual*/
 114   void connect_to_context (Context *c);
 115   void disconnect_from_context (Context *c);
 116
 117   void stop_translation_timestep ();
 118   void start_translation_timestep ();
 119   void process_music ();
 120   void process_acknowledged ();
 121
 122   Context *get_score_context () const;
 123   Global_context *get_global_context () const;
 124
 125   TRANSLATOR_DECLARATIONS (Translator);
 126   DECLARE_SMOBS (Translator);
 127
 128 protected:                      // should be private.
 129   Context *daddy_context_;
 130   void protect_event (SCM ev);
 131   virtual void derived_mark () const;
 132   static void add_translator_listener (translator_listener_record **listener_list, translator_listener_record *r, Listener (*get_listener) (void *), const char *ev_class);
 133   SCM static_translator_description (const char *grobs,
 134                                      const char *desc,
 135                                      translator_listener_record *listener_list,
 136                                      const char *read,
 137                                      const char *write) const;
 138
 139   friend class Translator_group;
 140 };
 141 void add_translator (Translator *trans);
 142
 143 Translator *get_translator (SCM s);
 144 Moment get_event_length (Stream_event *s);
 145 DECLARE_UNSMOB (Translator, translator);
 146
 147
 148 /*
 149   This helper is only meaningful inside listen_* methods.
 150 */
 151 extern bool internal_event_assignment (Stream_event **old_ev, Stream_event *new_ev, const char *function);
 152 #define ASSIGN_EVENT_ONCE(o,n) internal_event_assignment (&o, n, __FUNCTION__)
 153
 154
 155 #endif // TRANSLATOR_HH