Hi,
Sorry for the delay. Here's a new revision of the dispatcher system. Known
issues:
- Some trivial changes should be done to other files, e.g. lily.scm and
lily-proto.hh.
- I added the unique_ member to Context. It's just an int that's supposed to
be unique for each context. unique might not be the best name; suggestios for
better names are welcome.
And some comments:
On Wednesday 05 April 2006 14.10, Han-Wen Nienhuys wrote:
> Erik Sandberg wrote:
> > Some known issues:
> > - scm/define-event-classes.scm contains rather unsorted functions which
> > are
>
> i'm missing that file.
sorry, attached.
> > - The Stream_event class duplicates its 'context property with a context_
> > member; this was originally intended to give speedups, but it is broken
> > in this version and requires some modifications to Context in order to
> > work. I'll probably remove the context_ member altogether in the next
> > revision.
>
> yes please do.
>
> > /*
> > Event dispatching:
> > - Collect a list of listeners for each relevant class
> > - Send the event to each of these listeners, in increasing priority
> > order. This is done by keeping a bubble-sorted temporary list of listener
> > lists, and iteratively send the event to the lowest-priority listener. -
> > An event is never sent twice to listeners with equal priority. */
> > IMPLEMENT_LISTENER (Dispatcher, dispatch) (Stream_event *ev)
> > {
> > SCM class_symbol = ev->get_property ("class");
> > if (!scm_symbol_p (class_symbol))
> > {
> > warning (_f ("Unknown event class %s", ly_symbol2string
> > (class_symbol).c_str ())); return;
> > }
> >
> > SCM class_list = scm_primitive_eval (class_symbol);
>
> ugh. WTF is this? Where does this come from, in what module should it be
> defined. Why does this do an eval() for every dispatch() call?
I used eval as a poor man's hashq. I have cleaned it up a bit now, by
abstracting the eval call.
> > bool sent = false;
> >
> > // TODO: fix this loop.
> > int num_classes = 0;
> > for (SCM cl = class_list; cl != SCM_EOL; cl = scm_cdr (cl))
> > num_classes++;
>
> scm_ilength
thanks
> > // Collect all listener lists.
> > struct { int prio; SCM list; } lists[num_classes+1];
> > int i = 0;
> > for (SCM cl = class_list; cl != SCM_EOL; cl = scm_cdr (cl))
> > {
> > SCM list = scm_hashq_ref (listeners_, scm_car (cl), SCM_EOL);
> > if (list == SCM_EOL)
> > num_classes--;
> > else
> > {
> > // bubblesort.
> > int prio = scm_to_int (scm_caar (list));
> > int j;
> > for (j = i; j > 0 && lists[j-1].prio > prio; j--)
> > lists[j] = lists[j-1];
> > lists[j].prio = prio;
> > lists[j].list = list;
> > i++;
> > }
> > }
> > lists[num_classes].prio = INT_MAX;
>
> can you use a Scheme sort routine to do this?
>
> do I understand correctly that for every time step, we get multiple
> bubble sorts? That doesn't look very clean?
The bubble sorts are just a primitive implementation of a priority queue. The
queue typically has two elements (the height of the event-class tree), so I
felt that using pure C and simple bubble-sort would be the most efficient way
to do it. The main reason for C is that the stack is used for memory
allocation; I suspect this would be much slower in guile due to GC.
> > #if 0
> > /*
> > New listeners are appended to the end of the list.
> > This way, listeners will listen to an event in the order they were
> > added. */
>
> why if 0 ?
sorry, obsolete code
> > // We just remove the listener once.
> > bool first = true;
> >
> > SCM dummy = scm_cons (SCM_EOL, list);
> > SCM e = dummy;
> > while (scm_cdr (e) != SCM_EOL)
> > if (*unsmob_listener (scm_cdadr (e)) == l && first)
> > {
> > scm_set_cdr_x (e, scm_cddr(e));
> > first = false;
> > break;
> > }
> > else
> > e = scm_cdr (e);
> > list = scm_cdr (dummy);
>
> try to use scm_delq or similar, if not possible, devise an appropriate
> del() routine yoursefl.
Thanks, scm_delete seems to do the job (I didn't realise I had defined an
equality predicate)
> > #ifndef NDEBUG
> > // assert (SCM_EOL == scm_hashq_ref (listeners_, ly_symbol2scm
> > ("StreamEvent"), SCM_EOL)); #endif
>
> idem.
>
> > LY_DEFINE (ly_make_dispatcher, "ly:make-dispatcher",
>
> as a matter of style, this should be in dispatcher-scheme.cc
>
> > /*
> > listener-scheme.cc -- Connect listeners to Scheme through Scm_listener
> >
> > source file of the GNU LilyPond music typesetter
> >
> > (c) 2005-2006 Erik Sandberg <[EMAIL PROTECTED]>
> > */
> >
> > #include "listener.hh"
> > #include "ly-smobs.icc"
> > #include "stream-event.hh"
> >
> > class Scm_listener
>
> this should be in scm-listener.cc
>
> > {
> > public:
> > Scm_listener (SCM callback);
> > DECLARE_LISTENER (listener);
> > protected:
> > DECLARE_SMOBS (Scm_listener,);
> > private:
> > SCM callback_;
> > };
> >
> > IMPLEMENT_LISTENER (Scm_listener, listener) (Stream_event *ev)
>
> Please change the def of this macro so we can have
>
> IMPLEMENT_LISTENER (Scm_listener, listener);
> Scm_listener::real_declaration (Stream_event *)
>
> otherwise tools like TAGS get very confused.
I have changed the definition to:
IMPLEMENT_LISTENER (Scm_listener, listener, (Stream_event *ev))
{
...
}
Your suggestion doesn't work well because of some magic inside the macro.
> > LY_DEFINE (ly_make_listener, "ly:make-listener",
>
> scm-listener-scheme.cc
Scm_listener is only intended to be used locally by that function; splitting
the file into two modules would feel artificial/meaningless. Perhaps I should
rename the class to Listener_scheme?
> > // ES todo: Add stuff to lily-proto.hh: Stream_event and its subclasses,
> > Stream_creator, etc.
>
> yes. in any case, I'm missing a patch.
>
> > SCM
> > Stream_event::internal_get_property (SCM sym) const
> > {
> > SCM s = scm_sloppy_assq (sym, property_alist_);
> > if (s != SCM_BOOL_F)
> > return scm_cdr (s);
> > return SCM_EOL;
> > }
>
> you might want to consider basing these objects on Prob; see prob.cc
Is there a point in doing that? There are no immutable properties
> > #define SEND_EVENT_TO_CONTEXT(ctx, cl, ...) \
> > { \
> > Stream_event *_e_ = new Stream_event (ctx, ly_symbol2scm (cl)); \
> > __VA_ARGS__; \
> > ctx->event_source ()->distribute (_e_); \
> > scm_gc_unprotect_object (_e_->self_scm ());
> > \
> > }
> >
> > #define EVENT_PROPERTY(prop, val) \
> > (_e_->set_property (prop, val))
>
> what's this? Is it ever used? It looks fishy anyway.
It's used about 15 times so far. It's a shorthand for creating and reporting
an event; e.g., the following code generates and broadcasts a Revert event:
SEND_EVENT_TO_CONTEXT (get_outlet (), "Revert",
EVENT_PROPERTY("symbol", sym),
EVENT_PROPERTY("property", eprop));
> In general, it seems that Dispatcher is not connected to Stream_event at
> all. Why not make
I guess you mean listeners. I have now generalised them.
--
Erik
;;;; stream-event-classes.scm -- define the tree of stream-event classes.
;;;;
;;;; source file of the GNU LilyPond music typesetter
;;;;
;;;; (c) 2005-2006 Erik Sandberg <[EMAIL PROTECTED]>
(use-modules (srfi srfi-1))
;; Event class hierarchy. Each line is on the form ((List of children) . Parent)
(define event-classes
'(((StreamEvent) . '())
((RemoveContext ChangeParent Override Revert UnsetProperty SetProperty
MusicEvent CreateContext Prepare OneTimeStep Finish) . StreamEvent)
))
;; Each class will be defined as
;; (class parent grandparent .. )
;; so that (eq? (cdr class) parent) holds.
(for-each
(lambda (rel)
(for-each
(lambda (type)
(primitive-eval `(define ,type (cons ',type ,(cdr rel)))))
(car rel)))
event-classes)
;; TODO: Allow entering more complex classes, by taking unions.
(define-public (ly:make-event-class leaf)
(primitive-eval leaf)
(defmacro-public make-stream-event (expr)
(Stream_event::undump (primitive-eval (list 'quasiquote expr))))
(define* (simplify e)
(cond
;; Special case for lists reduces stack consumption.
((list? e) (map simplify e))
((pair? e) (cons (simplify (car e))
(simplify (cdr e))))
((ly:stream-event? e)
(list 'unquote `(make-stream-event ,(simplify (Stream_event::dump e)))))
((ly:music? e)
(list 'unquote (music->make-music e)))
((ly:moment? e)
(list 'unquote `(ly:make-moment
,(ly:moment-main-numerator e)
,(ly:moment-main-denominator e)
. ,(if (eq? 0 (ly:moment-grace-numerator e))
'()
(list (ly:moment-grace-numerator e)
(ly:moment-grace-denominator e))))))
((ly:duration? e)
(list 'unquote `(ly:make-duration
,(ly:duration-log e)
,(ly:duration-dot-count e)
,(car (ly:duration-factor e))
,(cdr (ly:duration-factor e)))))
((ly:pitch? e)
(list 'unquote `(ly:make-pitch
,(ly:pitch-octave e)
,(ly:pitch-notename e)
,(ly:pitch-alteration e))))
((ly:input-location? e)
(list 'unquote '(ly:dummy-input-location)))
(#t e)))
(define-public (ly:simplify-scheme e)
(list 'quasiquote (simplify e))
)
; used by lily/dispatcher.cc
(define-public (car< a b) (< (car a) (car b)))
Index: context.cc
===================================================================
RCS file: /sources/lilypond/lilypond/lily/context.cc,v
retrieving revision 1.78
diff -u -r1.78 context.cc
--- context.cc 12 Feb 2006 16:40:02 -0000 1.78
+++ context.cc 26 Apr 2006 18:55:29 -0000
@@ -96,6 +96,7 @@
accepts_list_ = SCM_EOL;
context_list_ = SCM_EOL;
definition_ = SCM_EOL;
+ unique_ = -1;
smobify_self ();
@@ -236,6 +237,7 @@
Context *new_context
= cdef->instantiate (ops, key);
+ new_context->unique_ = get_global_context()->new_unique();
new_context->id_string_ = id;
add_context (new_context);
apply_property_operations (new_context, ops);
Index: global-context.cc
===================================================================
RCS file: /sources/lilypond/lilypond/lily/global-context.cc,v
retrieving revision 1.40
diff -u -r1.40 global-context.cc
--- global-context.cc 31 Jan 2006 00:30:43 -0000 1.40
+++ global-context.cc 26 Apr 2006 18:55:29 -0000
@@ -204,3 +204,9 @@
else
return Context::get_default_interpreter ();
}
+
+int
+Global_context::new_unique ()
+{
+ return ++unique_count_;
+}
Index: include/context.hh
===================================================================
RCS file: /sources/lilypond/lilypond/lily/include/context.hh,v
retrieving revision 1.38
diff -u -r1.38 context.hh
--- include/context.hh 16 Feb 2006 11:54:21 -0000 1.38
+++ include/context.hh 26 Apr 2006 18:55:29 -0000
@@ -29,6 +29,7 @@
friend class Context_handle;
int iterator_count_;
bool init_;
+ int unique_;
protected:
Context *daddy_context_;
@@ -54,6 +55,7 @@
string id_string () const { return id_string_; }
SCM children_contexts () const { return context_list_; }
SCM default_child_context_name () const;
+ int get_unique() { return unique_; }
Translator_group *implementation () const { return implementation_; }
Context *get_parent_context () const;
Index: include/global-context.hh
===================================================================
RCS file: /sources/lilypond/lilypond/lily/include/global-context.hh,v
retrieving revision 1.13
diff -u -r1.13 global-context.hh
--- include/global-context.hh 6 Jan 2006 09:13:24 -0000 1.13
+++ include/global-context.hh 26 Apr 2006 18:55:29 -0000
@@ -16,6 +16,7 @@
{
PQueue<Moment> extra_mom_pq_;
Output_def *output_def_;
+ int unique_count_;
DECLARE_CLASSNAME(Global_context);
@@ -39,6 +40,7 @@
virtual Moment now_mom () const;
virtual Context *get_default_interpreter ();
+ int new_unique ();
Moment previous_moment () const;
protected:
Moment final_mom_;
/*
dispatcher.cc -- implement Dispatcher
source file of the GNU LilyPond music typesetter
(c) 2005-2006 Erik Sandberg <[EMAIL PROTECTED]>
*/
#include "dispatcher.hh"
#include "international.hh"
#include "ly-smobs.icc"
#include "stream-event.hh"
#include "warn.hh"
// ES todo: move to lily-guile.hh
SCM appendable_list ();
void appendable_list_append (SCM l, SCM elt);
IMPLEMENT_SMOBS (Dispatcher);
IMPLEMENT_TYPE_P (Dispatcher, "dispatcher");
IMPLEMENT_DEFAULT_EQUAL_P (Dispatcher);
Dispatcher::~Dispatcher ()
{
}
Dispatcher::Dispatcher ()
{
self_scm_ = SCM_EOL;
listeners_ = SCM_EOL;
dispatchers_ = SCM_EOL;
listen_classes_ = SCM_EOL;
smobify_self ();
//TODO use resizable hash
listeners_ = scm_c_make_hash_table (17);
priority_count_ = 0;
}
SCM
Dispatcher::mark_smob (SCM sm)
{
Dispatcher *me = (Dispatcher *) SCM_CELL_WORD_1 (sm);
scm_gc_mark (me->dispatchers_);
scm_gc_mark (me->listen_classes_);
return me->listeners_;
}
int
Dispatcher::print_smob (SCM s, SCM p, scm_print_state*)
{
Dispatcher *me = (Dispatcher *) SCM_CELL_WORD_1 (s);
scm_puts ("#<Dispatcher ", p);
scm_write (scm_vector_to_list (me->listeners_), p);
scm_puts (">", p);
return 1;
}
/*
Event dispatching:
- Collect a list of listeners for each relevant class
- Send the event to each of these listeners, in increasing priority order.
This is done by keeping a bubble-sorted temporary list of listener lists,
and iteratively send the event to the lowest-priority listener.
- An event is never sent twice to listeners with equal priority.
*/
IMPLEMENT_LISTENER (Dispatcher, dispatch, (SCM sev))
{
Stream_event *ev = unsmob_stream_event (sev);
SCM class_symbol = ev->get_property ("class");
if (!scm_symbol_p (class_symbol))
{
warning (_f ("Unknown event class %s", ly_symbol2string (class_symbol).c_str ()));
return;
}
SCM class_list = scm_call_1 (ly_lily_module_constant ("ly:make-event-class"), class_symbol);
bool sent = false;
int num_classes = scm_ilength (class_list);
// Collect all listener lists.
struct { int prio; SCM list; } lists[num_classes+1];
int i = 0;
for (SCM cl = class_list; scm_is_pair(cl); cl = scm_cdr (cl))
{
SCM list = scm_hashq_ref (listeners_, scm_car (cl), SCM_EOL);
if (!scm_is_pair(list))
num_classes--;
else
{
// bubblesort.
int prio = scm_to_int (scm_caar (list));
int j;
for (j = i; j > 0 && lists[j-1].prio > prio; j--)
lists[j] = lists[j-1];
lists[j].prio = prio;
lists[j].list = list;
i++;
}
}
lists[num_classes].prio = INT_MAX;
// Never send an event to two listeners with equal priority.
int last_priority = -1;
// Iteratively process all event classes, in increasing priority.
while (num_classes)
{
// Send the event, if we haven't already sent it to this target.
if (lists[0].prio != last_priority)
{
// process the listener
assert (lists[0].prio > last_priority);
last_priority = lists[0].prio;
Listener *l = unsmob_listener (scm_cdar (lists[0].list));
l->listen (ev->self_scm ());
sent = true;
}
// go to the next listener; bubble-sort the class list.
SCM next = scm_cdr (lists[0].list);
if (!scm_is_pair(next))
num_classes--;
int prio = (scm_is_pair(next)) ? scm_to_int (scm_caar (next)) : INT_MAX;
for (i = 0; prio > lists[i+1].prio; i++)
lists[i] = lists[i+1];
lists[i].prio = prio;
lists[i].list = next;
}
if (!sent)
warning (_f ("Junking event: %s", ly_symbol2string (class_symbol).c_str ()));
}
void
Dispatcher::broadcast (Stream_event *ev)
{
dispatch_proc (ev->self_scm ());
}
void
Dispatcher::add_listener (Listener l, SCM ev_class)
{
internal_add_listener (l, ev_class, ++priority_count_);
}
inline void
Dispatcher::internal_add_listener (Listener l, SCM ev_class, int priority)
{
SCM list = scm_hashq_ref (listeners_, ev_class, SCM_EOL);
if (list == SCM_EOL)
{
/* Register with all dispatchers. */
for (SCM disp = dispatchers_; scm_is_pair(disp); disp = scm_cdr (disp))
{
int priority = scm_to_int (scm_cdar (disp));
Dispatcher *d = unsmob_dispatcher (scm_caar (disp));
d->internal_add_listener (dispatch (), ev_class, priority);
}
listen_classes_ = scm_cons (ev_class, listen_classes_);
}
SCM entry = scm_cons (scm_int2num (priority), l.smobbed_copy ());
list = scm_merge_x (list, scm_list_1 (entry), ly_lily_module_constant ("car<"));
scm_hashq_set_x (listeners_, ev_class, list);
}
void
Dispatcher::remove_listener (Listener l, SCM ev_class)
{
SCM list = scm_hashq_ref (listeners_, ev_class, SCM_EOL);
if (list == SCM_EOL)
{
programming_error ("remove_listener called with incorrect class.");
return;
}
// We just remove the listener once.
bool first = true;
SCM dummy = scm_cons (SCM_EOL, list);
SCM e = dummy;
while (scm_is_pair(scm_cdr (e)))
if (*unsmob_listener (scm_cdadr (e)) == l && first)
{
scm_set_cdr_x (e, scm_cddr(e));
first = false;
break;
}
else
e = scm_cdr (e);
list = scm_cdr (dummy);
if (first)
warning ("Attempting to remove nonexisting listener.");
else if (list == SCM_EOL)
{
/* Unregister with all dispatchers. */
for (SCM disp = dispatchers_; disp != SCM_EOL; disp = scm_cdr (disp))
{
Dispatcher *d = unsmob_dispatcher (scm_caar (disp));
d->remove_listener (dispatch (), ev_class);
}
listen_classes_ = scm_delq_x (ev_class, listen_classes_);
}
}
/* Register as a listener to another dispatcher. */
void
Dispatcher::register_as_listener (Dispatcher *disp)
{
int priority = ++disp->priority_count_;
// Don't register twice to the same dispatcher.
if (scm_assq (disp->self_scm (), dispatchers_) != SCM_BOOL_F)
{
warning ("Already listening to dispatcher, ignoring request");
return;
}
dispatchers_ = scm_acons (disp->self_scm (), scm_int2num (priority), dispatchers_);
Listener list = dispatch ();
for (SCM cl = listen_classes_; cl != SCM_EOL; cl = scm_cdr (cl))
{
disp->internal_add_listener (list, scm_car (cl), priority);
}
}
/* Unregister as a listener to another dispatcher. */
void
Dispatcher::unregister_as_listener (Dispatcher *disp)
{
dispatchers_ = scm_assq_remove_x (dispatchers_, disp->self_scm ());
Listener list = dispatch ();
for (SCM cl = listen_classes_; cl != SCM_EOL; cl = scm_cdr (cl))
{
disp->remove_listener (list, scm_car (cl));
}
}
/*
stream-event.cc -- implement Stream_event
source file of the GNU LilyPond music typesetter
(c) 2005-2006 Erik Sandberg <[EMAIL PROTECTED]>
*/
#include "stream-event.hh"
#include "ly-smobs.icc"
#include "context.hh"
#include "input.hh"
#include "input-smob.hh"
// ES todo: Add stuff to lily-proto.hh: Stream_event and its subclasses, Stream_creator, etc.
Stream_event::~Stream_event ()
{
}
void
Stream_event::init ()
{
self_scm_ = SCM_EOL;
property_alist_ = SCM_EOL;
origin_ = 0;
smobify_self ();
}
Stream_event::Stream_event ()
{
init ();
}
Stream_event::Stream_event (Context *c, Input *origin)
{
init ();
set_property ("context", scm_int2num (c->get_unique()));
origin_ = origin;
}
Stream_event::Stream_event (SCM property_alist)
{
init ();
property_alist_ = property_alist;
origin_ = &dummy_input_global;
}
Stream_event::Stream_event (Context *c, SCM class_name)
{
init ();
set_property ("context", scm_int2num (c->get_unique()));
set_property ("class", class_name);
origin_ = &dummy_input_global;
}
Stream_event::Stream_event (Stream_event *ev)
{
init ();
property_alist_ = scm_copy_tree (ev->property_alist_);
origin_ = ev->origin_;
}
Input *
Stream_event::origin () const
{
return origin_;
}
SCM
Stream_event::mark_smob (SCM sm)
{
Stream_event *me = (Stream_event *) SCM_CELL_WORD_1 (sm);
return me->property_alist_;
}
int
Stream_event::print_smob (SCM s, SCM port, scm_print_state *)
{
scm_puts ("#<Stream_event ", port);
scm_write (dump (s), port);
scm_puts (" >", port);
return 1;
}
IMPLEMENT_SMOBS (Stream_event);
IMPLEMENT_DEFAULT_EQUAL_P (Stream_event);
IMPLEMENT_TYPE_P (Stream_event, "ly:stream-event?");
MAKE_SCHEME_CALLBACK (Stream_event, undump, 1);
MAKE_SCHEME_CALLBACK (Stream_event, dump, 1);
SCM
Stream_event::dump (SCM self)
{
Stream_event *ev = unsmob_stream_event (self);
// Reversed alists look prettier.
return scm_reverse (ev->property_alist_);
}
SCM
Stream_event::undump (SCM data)
{
Stream_event *obj = new Stream_event ();
obj->property_alist_ = scm_reverse (data);
return obj->unprotect ();
}
SCM
Stream_event::internal_get_property (SCM sym) const
{
SCM s = scm_sloppy_assq (sym, property_alist_);
if (s != SCM_BOOL_F)
return scm_cdr (s);
return SCM_EOL;
}
void
Stream_event::internal_set_property (SCM prop, SCM val)
{
property_alist_ = scm_assq_set_x (property_alist_, prop, val);
}
/*
stream-event.cc -- implement Scheme bindings for Stream_event
source file of the GNU LilyPond music typesetter
(c) 2006 Erik Sandberg <[EMAIL PROTECTED]>
*/
#include "stream-event.hh"
LY_DEFINE (ly_make_stream_event, "ly:make-stream-event",
1, 0, 0, (SCM proplist),
"Creates a stream event, with the given property list.\n" )
{
SCM_ASSERT_TYPE (scm_list_p (proplist), proplist, SCM_ARG1, __FUNCTION__, "association list");
Stream_event *e = new Stream_event (proplist);
return e->unprotect ();
}
LY_DEFINE (ly_stream_event_property, "ly:stream-event-property",
2, 0, 0, (SCM sev, SCM sym),
"Get the property @var{sym} of stream event @var{mus}.\n"
"If @var{sym} is undefined, return @code{' ()}.\n")
{
Stream_event *e = unsmob_stream_event (sev);
SCM_ASSERT_TYPE (e, sev, SCM_ARG1, __FUNCTION__, "stream event");
SCM_ASSERT_TYPE (scm_is_symbol (sym), sym, SCM_ARG2, __FUNCTION__, "symbol");
return e->internal_get_property (sym);
}
/*
dispatcher.cc -- implement Scheme bindings for Dispatcher
source file of the GNU LilyPond music typesetter
(c) 2006 Erik Sandberg <[EMAIL PROTECTED]>
*/
#include "dispatcher.hh"
LY_DEFINE (ly_make_dispatcher, "ly:make-dispatcher",
0, 0, 0, (),
"Returns a newly created dispatcher.")
{
return (new Dispatcher ())->unprotect ();
}
LY_DEFINE (ly_register_dispatcher, "ly:connect-dispatchers",
2, 0, 0, (SCM to, SCM from),
"Makes the dispatcher @var{to} listen to events from @var{from}." )
{
Dispatcher *t = unsmob_dispatcher (to);
Dispatcher *f = unsmob_dispatcher (from);
SCM_ASSERT_TYPE (t, from, SCM_ARG1, __FUNCTION__, "dispatcher");
SCM_ASSERT_TYPE (f, to, SCM_ARG2, __FUNCTION__, "dispatcher");
t->register_as_listener (f);
return SCM_UNDEFINED;
}
LY_DEFINE (ly_add_listener, "ly:add-listener",
2, 0, 1, (SCM list, SCM disp, SCM cl),
"Adds the listener @var{list} to the dispatcher @var{disp}.\n"
" Whenever @var{disp} hears an event of class @var{cl}, it will be forwarded to @var{list}.\n" )
{
Listener *l = unsmob_listener (list);
Dispatcher *d = unsmob_dispatcher (disp);
SCM_ASSERT_TYPE (l, list, SCM_ARG1, __FUNCTION__, "listener");
SCM_ASSERT_TYPE (d, disp, SCM_ARG2, __FUNCTION__, "dispatcher");
for (int arg=SCM_ARG3; cl != SCM_EOL; cl = scm_cdr (cl), arg++)
{
SCM_ASSERT_TYPE (scm_symbol_p (cl), cl, arg, __FUNCTION__, "symbol");
d->add_listener (*l, scm_car (cl));
}
return SCM_UNDEFINED;
}
LY_DEFINE (ly_broadcast, "ly:broadcast",
2, 0, 0, (SCM disp, SCM ev),
"Sends the stream event @var{ev} to the dispatcher\n"
"@var{disp}.")
{
Dispatcher *d = unsmob_dispatcher (disp);
Stream_event *e = unsmob_stream_event (ev);
SCM_ASSERT_TYPE (d, disp, SCM_ARG1, __FUNCTION__, "dispatcher");
SCM_ASSERT_TYPE (e, ev, SCM_ARG2, __FUNCTION__, "stream event");
d->broadcast (e);
return SCM_UNDEFINED;
}
/*
listener-scheme.cc -- Connect listeners to Scheme through Scm_listener
source file of the GNU LilyPond music typesetter
(c) 2005-2006 Erik Sandberg <[EMAIL PROTECTED]>
*/
#include "listener.hh"
#include "ly-smobs.icc"
#include "stream-event.hh"
class Scm_listener
{
public:
Scm_listener (SCM callback);
DECLARE_LISTENER (listener);
protected:
DECLARE_SMOBS (Scm_listener,);
private:
SCM callback_;
};
IMPLEMENT_LISTENER (Scm_listener, listener, (SCM ev))
{
scm_call_1 (callback_, ev);
}
IMPLEMENT_SMOBS (Scm_listener);
IMPLEMENT_DEFAULT_EQUAL_P (Scm_listener);
Scm_listener::Scm_listener (SCM c)
{
callback_ = SCM_EOL;
self_scm_ = SCM_EOL;
smobify_self ();
callback_ = c;
}
SCM
Scm_listener::mark_smob (SCM obj)
{
Scm_listener *me = (Scm_listener *) SCM_CELL_WORD_1 (obj);
return me->callback_;
}
int
Scm_listener::print_smob (SCM obj, SCM p, scm_print_state*)
{
Scm_listener *me = (Scm_listener *) SCM_CELL_WORD_1 (obj);
scm_puts ("#<Scm_listener ", p);
scm_write (me->callback_, p);
scm_puts (">", p);
return 1;
}
Scm_listener::~Scm_listener ()
{
}
LY_DEFINE (ly_make_listener, "ly:make-listener",
1, 0, 0, (SCM callback),
"Creates a listener. Any time the listener hears\n"
" an object, it will call @var{callback}\n"
" with that object. @var{callback} should take exactly one argument." )
{
SCM_ASSERT_TYPE (scm_procedure_p (callback), callback, SCM_ARG1, __FUNCTION__, "procedure");
Scm_listener *l = new Scm_listener (callback);
SCM listener = l->listener ().smobbed_copy ();
l->unprotect ();
return listener;
}
/*
listener.cc -- implement Listener and Listener_target
source file of the GNU LilyPond music typesetter
(c) 2005 Erik Sandberg <[EMAIL PROTECTED]>
*/
#include "listener.hh"
#include "ly-smobs.icc"
#include "warn.hh"
/*
Listener_target::~Listener_target ()
{
}
*/
Listener::Listener (const void *target, Listener_function_table *type)
{
target_ = (void *)target;
type_ = type;
}
Listener::Listener (Listener const &other)
{
target_ = other.target_;
type_ = other.type_;
}
void Listener::listen (SCM ev) const {
(type_->listen_callback) (target_, ev);
}
SCM
Listener::mark_smob (SCM sm)
{
Listener *me = (Listener *) SCM_CELL_WORD_1 (sm);
(me->type_->mark_callback) (me->target_);
return SCM_EOL;
}
int
Listener::print_smob (SCM s, SCM p, scm_print_state*)
{
scm_puts ("#<Listener>", p);
return 1;
}
SCM
Listener::equal_p (SCM a, SCM b)
{
Listener *l1 = unsmob_listener (a);
Listener *l2 = unsmob_listener (b);
return (*l1 == *l2) ? SCM_BOOL_T : SCM_BOOL_F;
}
IMPLEMENT_SIMPLE_SMOBS (Listener);
IMPLEMENT_TYPE_P (Listener, "listener");
/*
listener.hh -- declare Listener
source file of the GNU LilyPond music typesetter
(c) 2005 Erik Sandberg <[EMAIL PROTECTED]>
*/
#ifndef LISTENER_HH
#define LISTENER_HH
/*
Listeners
Listeners are used for stream event dispatching. If you want to
register a method as an event handler in a dispatcher, then you
must:
- declare the method using DECLARE_LISTENER:
class Foo
{
DECLARE_LISTENER (method);
...
};
- implement the method using IMPLEMENT_LISTENER:
IMPLEMENT_LISTENER (Foo, method, (Stream_event *e))
{
write ("Foo hears an event!");
}
- register the method to the dispatcher using Dispatcher::register
Foo *foo = (...);
Stream_distributor *d = (...);
Listener l = foo->method ();
d->register_listener (l, "EventClass");
Whenever d hears a stream-event ev of class "EventClass",
the implemented procedure is called.
DECLARE_LISTENER currently only works inside smob classes.
*/
#include "smobs.hh"
/*TODO: to lily-proto*/
class Stream_event;
typedef struct {
void (*listen_callback) (void *, SCM);
void (*mark_callback) (void *);
} Listener_function_table;
class Listener {
void *target_;
Listener_function_table *type_;
public:
Listener (const void *target, Listener_function_table *type);
Listener (Listener const &other);
void listen (SCM ev) const;
bool operator == (Listener const &other) const
{ return target_ == other.target_ && type_ == other.type_; }
DECLARE_SIMPLE_SMOBS (Listener,);
};
DECLARE_UNSMOB (Listener, listener);
#define IMPLEMENT_LISTENER(cl, method, params) \
void \
cl :: method ## _callback (void *self, SCM ev) \
{ \
cl *s = (cl *)self; \
s->method ## _proc (ev); \
} \
void \
cl :: method ## _mark (void *self) \
{ \
cl *s = (cl *)self; \
scm_gc_mark (s->self_scm ()); \
} \
Listener \
cl :: method () const \
{ \
static Listener_function_table callbacks; \
callbacks.listen_callback = &cl::method ## _callback; \
callbacks.mark_callback = &cl::method ## _mark; \
return Listener (this, &callbacks); \
} \
void \
cl :: method ## _proc params
#define DECLARE_LISTENER(name) \
inline void name ## _proc (SCM); \
static void name ## _callback (void *self, SCM ev); \
static void name ## _mark (void *self); \
Listener name () const
#endif /* LISTENER_HH */
/*
dispatcher.hh -- declare Dispatcher
source file of the GNU LilyPond music typesetter
(c) 2005 Erik Sandberg <[EMAIL PROTECTED]>
*/
#ifndef DISPATCHER_HH
#define DISPATCHER_HH
#include "listener.hh"
#include "stream-event.hh"
class Dispatcher
{
/* Hash table. Each event-class maps to a list of listeners. */
SCM listeners_;
/* alist of dispatchers that we listen to. Each entry is a
(dist . priority) pair. */
SCM dispatchers_;
SCM listen_classes_;
DECLARE_LISTENER (dispatch);
/* priority counter. Listeners with low priority receive events
first. */
int priority_count_;
void internal_add_listener (Listener, SCM event_class, int priority);
public:
Dispatcher ();
void broadcast (Stream_event *ev);
void add_listener (Listener, SCM event_class);
void remove_listener (Listener, SCM event_class);
void register_as_listener (Dispatcher *dist);
void unregister_as_listener (Dispatcher *dist);
protected:
DECLARE_SMOBS (Dispatcher,);
};
DECLARE_UNSMOB (Dispatcher, dispatcher);
#endif // DISPATCHER_HH
/*
stream-event.hh -- declare Stream_event
source file of the GNU LilyPond music typesetter
(c) 2005-2006 Erik Sandberg <[EMAIL PROTECTED]>
*/
#ifndef STREAM_EVENT_HH
#define STREAM_EVENT_HH
#include "lily-proto.hh"
#include "smobs.hh"
#include "prob.hh"
class Stream_event
{
void init ();
SCM property_alist_;
Input *origin_;
public:
Stream_event ();
Input *origin () const;
DECLARE_SCHEME_CALLBACK (undump, (SCM));
DECLARE_SCHEME_CALLBACK (dump, (SCM));
// todo: make Input mandatory.
Stream_event (SCM property_alist);
Stream_event (Context *c, SCM class_name);
Stream_event (Context *c, Input *);
Stream_event (Stream_event *ev);
SCM internal_get_property (SCM) const;
void internal_set_property (SCM prop, SCM val);
protected:
DECLARE_SMOBS (Stream_event,);
};
DECLARE_UNSMOB (Stream_event, stream_event);
DECLARE_TYPE_P (Stream_event);
#define SEND_EVENT_TO_CONTEXT(ctx, cl, ...) \
{ \
Stream_event *_e_ = new Stream_event (ctx, ly_symbol2scm (cl)); \
__VA_ARGS__; \
ctx->event_source ()->distribute (_e_); \
scm_gc_unprotect_object (_e_->self_scm ()); \
}
#define EVENT_PROPERTY(prop, val) \
(_e_->set_property (prop, val))
#endif /* STREAM_EVENT_HH */
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