lily/listener.cc

   1 /*
   2   listener.cc -- implement Listener and Listener_target
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2005 Erik Sandberg  <mandolaerik@gmail.com>
   7 */
   8
   9 #include "listener.hh"
  10 #include "ly-smobs.icc"
  11 #include "warn.hh"
  12
  13 Listener::Listener ()
  14 {
  15   target_ = 0;
  16   type_ = 0;
  17 }
  18
  19 Listener::Listener (const void *target, Listener_function_table *type)
  20 {
  21   target_ = (void *)target;
  22   type_ = type;
  23 }
  24
  25 Listener::Listener (Listener const &other)
  26 {
  27   target_ = other.target_;
  28   type_ = other.type_;
  29 }
  30
  31 void Listener::listen (SCM ev) const {
  32   (type_->listen_callback) (target_, ev);
  33 }
  34
  35 SCM
  36 Listener::mark_smob (SCM sm)
  37 {
  38   Listener *me = (Listener *) SCM_CELL_WORD_1 (sm);
  39   if (me->type_)
  40     (me->type_->mark_callback) (me->target_);
  41   return SCM_EOL;
  42 }
  43
  44 int
  45 Listener::print_smob (SCM, SCM p, scm_print_state*)
  46 {
  47   scm_puts ("#<Listener>", p);
  48   return 1;
  49 }
  50
  51 SCM
  52 Listener::equal_p (SCM a, SCM b)
  53 {
  54   Listener *l1 = unsmob_listener (a);
  55   Listener *l2 = unsmob_listener (b);
  56
  57   return (*l1 == *l2) ? SCM_BOOL_T : SCM_BOOL_F;
  58 }
  59
  60 IMPLEMENT_SIMPLE_SMOBS (Listener);
  61 IMPLEMENT_TYPE_P (Listener, "ly:listener?");