lily/include/translator.hh

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2015 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 #define TRANSLATOR_FAMILY_DECLARATIONS(NAME)                            \
  32   public:                                                               \
  33   VIRTUAL_COPY_CONSTRUCTOR (Translator, NAME);                          \
  34   static Drul_array<vector<Acknowledge_information> > acknowledge_static_array_drul_; \
  35   virtual void fetch_precomputable_methods (Callback methods[]);        \
  36   static Grob_info_callback static_get_acknowledger (SCM sym);          \
  37   static Grob_info_callback static_get_end_acknowledger(SCM);           \
  38   virtual Grob_info_callback get_acknowledger (SCM sym)                 \
  39   {                                                                     \
  40     return static_get_acknowledger (sym);                               \
  41   }                                                                     \
  42   virtual Grob_info_callback get_end_acknowledger (SCM sym)             \
  43   {                                                                     \
  44     return static_get_end_acknowledger (sym);                           \
  45   }                                                                     \
  46   /* end #define */
  47
  48 /*
  49   Each translator class has a static alist of event class symbols
  50   mapping to callbacks that are called with a translator instance and
  51   a stream event when an event of the appropriate event class is
  52   announced in a context.
  53 */
  54
  55 #define TRANSLATOR_DECLARATIONS(NAME)                                   \
  56   TRANSLATOR_FAMILY_DECLARATIONS(NAME)                                  \
  57   static SCM static_description_;                                       \
  58   static Protected_scm listener_list_;                                  \
  59 public:                                                                 \
  60   NAME ();                                                              \
  61   virtual SCM static_translator_description () const;                   \
  62   virtual SCM translator_description () const;                          \
  63   virtual SCM get_listener_list () const                                \
  64   {                                                                     \
  65     return listener_list_;                                              \
  66   }                                                                     \
  67   /* end #define */
  68
  69 #define DECLARE_TRANSLATOR_LISTENER(m)                  \
  70 public:                                                 \
  71 inline void listen_ ## m (Stream_event *);              \
  72 /* Should be private */                                 \
  73 static void _internal_declare_ ## 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 : public Smob<Translator>
  91 {
  92 public:
  93   // We don't make Grob_info_callback specific to Engraver since we
  94   // otherwise get into a circular mess with regard to the definitions
  95   // as the timing of Engraver is exercised from within Translator
  96   typedef void (Translator::*Grob_info_callback) (Grob_info);
  97   typedef void (Translator::*Callback) (void);
  98   int print_smob (SCM, scm_print_state *) const;
  99   SCM mark_smob () const;
 100   static const char type_p_name_[];
 101   virtual ~Translator ();
 102 private:
 103   void init ();
 104
 105 public:
 106   Context *context () const { return daddy_context_; }
 107
 108   Translator (Translator const &);
 109
 110   SCM internal_get_property (SCM symbol) const;
 111
 112   virtual Output_def *get_output_def () const;
 113   virtual Translator_group *get_daddy_translator ()const;
 114   virtual Moment now_mom () const;
 115   virtual bool must_be_last () const;
 116
 117   virtual void initialize ();
 118   virtual void finalize ();
 119
 120   virtual void connect_to_context (Context *c);
 121   virtual void disconnect_from_context (Context *c);
 122
 123   void stop_translation_timestep ();
 124   void start_translation_timestep ();
 125   void process_music ();
 126   void process_acknowledged ();
 127
 128   Context *get_score_context () const;
 129   Global_context *get_global_context () const;
 130
 131   TRANSLATOR_DECLARATIONS (Translator);
 132
 133 protected:                      // should be private.
 134   Context *daddy_context_;
 135   void protect_event (SCM ev);
 136
 137   template <class T, void (T::*callback)(Stream_event *)>
 138   static SCM trampoline (SCM target, SCM event)
 139   {
 140     T *t = unsmob<T> (target);
 141     LY_ASSERT_SMOB (T, target, 1);
 142     LY_ASSERT_SMOB (Stream_event, event, 2);
 143
 144     t->protect_event (event);
 145     (t->*callback) (unsmob<Stream_event> (event));
 146     return SCM_UNSPECIFIED;
 147   }
 148
 149   virtual void derived_mark () const;
 150   static SCM event_class_symbol (const char *ev_class);
 151   SCM static_translator_description (const char *grobs,
 152                                      const char *desc,
 153                                      SCM listener_list,
 154                                      const char *read,
 155                                      const char *write) const;
 156
 157   friend class Translator_group;
 158 };
 159
 160 struct Acknowledge_information
 161 {
 162   SCM symbol_;
 163   Translator::Grob_info_callback function_;
 164
 165   Acknowledge_information ()
 166   {
 167     symbol_ = SCM_EOL;
 168     function_ = 0;
 169   }
 170 };
 171
 172
 173 void add_translator (Translator *trans);
 174
 175 Translator *get_translator (SCM s);
 176 Moment get_event_length (Stream_event *s, Moment now);
 177 Moment get_event_length (Stream_event *s);
 178
 179 /*
 180   This helper is only meaningful inside listen_* methods.
 181 */
 182 extern bool internal_event_assignment (Stream_event **old_ev, Stream_event *new_ev, const char *function);
 183 #define ASSIGN_EVENT_ONCE(o,n) internal_event_assignment (&o, n, __FUNCTION__)
 184
 185 #endif // TRANSLATOR_HH