]> git.donarmstrong.com Git - lilypond.git/blobdiff - lily/include/translator.hh
lilypond-manuals.css: edit color scheme and some spacing
[lilypond.git] / lily / include / translator.hh
index 858af4ce21454b4a6b710811c269cdb022b0626a..91bd59fe4aef5c72efe334a9687a04dd2d1626ad 100644 (file)
@@ -1,7 +1,7 @@
 /*
   This file is part of LilyPond, the GNU music typesetter.
 
-  Copyright (C) 1997--2014 Han-Wen Nienhuys <hanwen@xs4all.nl>
+  Copyright (C) 1997--2015 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
 #include "global-ctor.hh"
 #include "lily-proto.hh"
 #include "virtual-methods.hh"
+#include "callback.hh"
 #include "input.hh"             // for error reporting
 #include "smobs.hh"
+#include "stream-event.hh"
 #include "std-vector.hh"
 #include "protected-scm.hh"
 
-struct Acknowledge_information
+// The Translator_creator class is only for translators defined in C.
+// Its elements are callable entities taking a context argument and
+// returning a corresponding translator.
+//
+// Other translator-creating entities may be alists and functions returning
+// such alists.  Information for those, such as created grobs/properties
+// is attached via object properties.
+
+// Smob rather than Simple_smob since we want an entity for
+// property lookup.
+
+class Translator_creator : public Smob<Translator_creator>
 {
-  SCM symbol_;
-  Engraver_void_function_engraver_grob_info function_;
+  Translator_creator (Translator_creator const &); // don't define
+  Translator * (*allocate_)(Context *);
+  template <class T>
+  static Translator *allocate (Context *ctx);
 
-  Acknowledge_information ()
+  Translator_creator (Translator * (*allocate)(Context *))
+    : allocate_(allocate)
+  {
+    smobify_self ();
+  }
+public:
+  // This is stupid, but constructors cannot have explicit template
+  // argument lists.
+  template <class T>
+  static Translator_creator *alloc()
   {
-    symbol_ = SCM_EOL;
-    function_ = 0;
+    return new Translator_creator(&allocate<T>);
   }
+  SCM call (SCM ctx);
+  LY_DECLARE_SMOB_PROC (&Translator_creator::call, 1, 0, 0);
 };
 
-/*
-  Each translator class has a static list of listener records. Each
-  record makes one explains how to register one of the class's stream event
-  listeners to a context.
-*/
-typedef struct translator_listener_record
+template <class T> Translator *
+Translator_creator::allocate (Context *ctx)
 {
-  Listener (*get_listener_) (void *, SCM event_class);
-  SCM event_class_;
-  struct translator_listener_record *next_;
+  return new T(ctx);
+}
 
-  translator_listener_record ()
-  {
-    next_ = 0;
-    event_class_ = SCM_EOL;
-    get_listener_ = 0;
-  }
+#define TRANSLATOR_FAMILY_DECLARATIONS(NAME)                            \
+  public:                                                               \
+  DECLARE_CLASSNAME (NAME);                                             \
+  virtual void fetch_precomputable_methods (SCM methods[]);             \
+  DECLARE_TRANSLATOR_CALLBACKS (NAME);                                  \
+  TRANSLATOR_INHERIT (Translator);                                      \
+  /* end #define */
 
-} translator_listener_record;
+#define TRANSLATOR_INHERIT(BASE)                                        \
+  using BASE::method_finder
 
-#define TRANSLATOR_DECLARATIONS_NO_LISTENER(NAME)                       \
-private:                                                                \
-  public:                                                               \
-  NAME ();                                                              \
-  VIRTUAL_COPY_CONSTRUCTOR (Translator, NAME);                          \
-  static SCM static_description_;                                       \
-  static Drul_array<vector<Acknowledge_information> > acknowledge_static_array_drul_; \
-  virtual void fetch_precomputable_methods (Translator_void_method_ptr methods[]); \
-  virtual SCM static_translator_description () const;                   \
-  virtual SCM translator_description () const;                          \
-  static Engraver_void_function_engraver_grob_info static_get_acknowledger (SCM sym); \
-  static Engraver_void_function_engraver_grob_info static_get_end_acknowledger(SCM); \
-  virtual Engraver_void_function_engraver_grob_info get_acknowledger (SCM sym) \
+#define DECLARE_TRANSLATOR_CALLBACKS(NAME)                              \
+  template <void (NAME::*mf)()>                                         \
+  static SCM method_finder ()                                           \
   {                                                                     \
-    return static_get_acknowledger (sym);                               \
+    return Callback0_wrapper::make_smob<NAME, mf> ();                   \
   }                                                                     \
-  virtual Engraver_void_function_engraver_grob_info get_end_acknowledger (SCM sym) \
+  template <void (NAME::*mf)(Stream_event *)>                           \
+  static SCM method_finder ()                                           \
   {                                                                     \
-    return static_get_end_acknowledger (sym);                           \
-  } \
+    return Callback_wrapper::make_smob<trampoline<NAME, mf> > ();       \
+  }                                                                     \
+  template <void (NAME::*mf)(Grob_info)>                                \
+  static SCM method_finder () {                                         \
+    return Callback2_wrapper::make_smob<trampoline <NAME, mf> > ();     \
+  }                                                                     \
   /* end #define */
 
+/*
+  Each translator class has a static alist of event class symbols
+  mapping to callbacks that are called with a translator instance and
+  a stream event when an event of the appropriate event class is
+  announced in a context.
+*/
+
 #define TRANSLATOR_DECLARATIONS(NAME)                                   \
-  TRANSLATOR_DECLARATIONS_NO_LISTENER(NAME)                             \
-private:                                                                \
-  static translator_listener_record *listener_list_;                    \
+  public:                                                               \
+  TRANSLATOR_FAMILY_DECLARATIONS (NAME);                                \
+  static Drul_array<Protected_scm> acknowledge_static_array_drul_;      \
+  static Protected_scm listener_list_;                                  \
+  static SCM static_get_acknowledger (SCM sym, Direction start_end);    \
+  virtual SCM get_acknowledger (SCM sym, Direction start_end)           \
+  {                                                                     \
+    return static_get_acknowledger (sym, start_end);                    \
+  }                                                                     \
 public:                                                                 \
-  virtual translator_listener_record *get_listener_list () const        \
+  NAME (Context *);                                                     \
+  static void boot ();                                                  \
+  static SCM static_translator_description ();                          \
+  virtual SCM get_listener_list () const                                \
   {                                                                     \
     return listener_list_;                                              \
   }                                                                     \
   /* end #define */
 
-#define DECLARE_TRANSLATOR_LISTENER(m)                  \
-public:                                                 \
-inline void listen_ ## m (Stream_event *);              \
-/* Should be private */                                 \
-static void _internal_declare_ ## m ();                 \
-private:                                                \
- static Listener _get_ ## m ## _listener (void *, SCM); \
-DECLARE_LISTENER (_listen_scm_ ## m);
-
-#define DECLARE_ACKNOWLEDGER(x) public : void acknowledge_ ## x (Grob_info); protected:
-#define DECLARE_END_ACKNOWLEDGER(x) public : void acknowledge_end_ ## x (Grob_info); protected:
-
 enum Translator_precompute_index
 {
   START_TRANSLATION_TIMESTEP,
@@ -117,14 +138,21 @@ enum Translator_precompute_index
 /*
   Translate music into grobs.
 */
-class Translator
+class Translator : public Smob<Translator>
 {
-  void init ();
-
 public:
+  int print_smob (SCM, scm_print_state *) const;
+  SCM mark_smob () const;
+  static const char * const type_p_name_;
+  virtual ~Translator ();
+
   Context *context () const { return daddy_context_; }
 
-  Translator (Translator const &);
+protected:
+  Translator (Context *);
+private:
+  Translator (Translator const &); // not copyable
+public:
 
   SCM internal_get_property (SCM symbol) const;
 
@@ -147,32 +175,54 @@ public:
   Context *get_score_context () const;
   Global_context *get_global_context () const;
 
-  TRANSLATOR_DECLARATIONS (Translator);
-  DECLARE_SMOBS (Translator);
+  DECLARE_CLASSNAME (Translator);
+
+  virtual void fetch_precomputable_methods (SCM methods[]) = 0;
+  virtual SCM get_listener_list () const = 0;
+  virtual SCM get_acknowledger (SCM sym, Direction start_end) = 0;
 
 protected:                      // should be private.
   Context *daddy_context_;
   void protect_event (SCM ev);
+
+  template <class T, void (T::*callback)(Stream_event *)>
+  static SCM trampoline (SCM target, SCM event)
+  {
+    T *t = unsmob<T> (target);
+    LY_ASSERT_SMOB (T, target, 1);
+    LY_ASSERT_SMOB (Stream_event, event, 2);
+
+    t->protect_event (event);
+    (t->*callback) (unsmob<Stream_event> (event));
+    return SCM_UNSPECIFIED;
+  }
+
+  // Fallback for non-overriden callbacks for which &T::x degrades to
+  // &Translator::x
+  template <void (Translator::*)()>
+  static SCM
+  method_finder () { return SCM_UNDEFINED; }
+
   virtual void derived_mark () const;
-  static void add_translator_listener (translator_listener_record **listener_list,
-                                       translator_listener_record *r,
-                                       Listener (*get_listener) (void *, SCM),
-                                       const char *ev_class);
-  SCM static_translator_description (const char *grobs,
-                                     const char *desc,
-                                     translator_listener_record *listener_list,
-                                     const char *read,
-                                     const char *write) const;
+  static SCM event_class_symbol (const char *ev_class);
+  static SCM
+  static_translator_description (const char *grobs,
+                                 const char *desc,
+                                 SCM listener_list,
+                                 const char *read,
+                                 const char *write);
 
   friend class Translator_group;
 };
 
-void add_translator (Translator *trans);
+SCM
+generic_get_acknowledger (SCM sym, SCM ack_hash);
+
+void add_translator_creator (SCM creator, SCM name, SCM description);
 
-Translator *get_translator (SCM s);
+SCM get_translator_creator (SCM s);
 Moment get_event_length (Stream_event *s, Moment now);
 Moment get_event_length (Stream_event *s);
-DECLARE_UNSMOB (Translator, translator);
 
 /*
   This helper is only meaningful inside listen_* methods.