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/*
* libzvbi - Events
*
* Copyright (C) 2004, 2008 Michael H. Schimek
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA.
*/
/* $Id: event.c,v 1.2 2009-12-14 23:43:35 mschimek Exp $ */
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "misc.h" /* CLEAR() */
#include "event-priv.h"
/**
* @internal
* @param es Event handler list.
* @param ev The event to send.
*
* Traverses the list of event handlers and calls each handler waiting
* for the @a ev->type of event, passing @a ev as parameter.
*/
void
__vbi_event_handler_list_send (_vbi_event_handler_list * el, vbi_event * ev)
{
vbi_event_handler_rec *eh, **ehp;
unsigned int ref_count;
assert (NULL != el);
assert (NULL != ev);
if (0 == (el->event_mask & ev->type))
return;
ref_count = el->ref_count + 1;
if (unlikely (0 == ref_count))
return;
el->ref_count = ref_count;
for (eh = el->first; NULL != eh; eh = eh->next) {
if (0 != (eh->event_mask & ev->type) && !eh->remove) {
eh->callback (ev, eh->user_data);
}
}
el->ref_count = --ref_count;
if (ref_count > 0)
return;
ehp = &el->first;
while (NULL != (eh = *ehp)) {
if (eh->remove) {
*ehp = eh->next;
vbi_free (eh);
} else {
ehp = &eh->next;
}
}
}
/**
* @internal
* @param el Event handler list.
* @param event_mask Event mask.
*
* Removes all handlers from the list which handle
* only events given in the @a event_mask.
*/
void _vbi_event_handler_list_remove_by_event
(_vbi_event_handler_list * el, vbi_event_mask event_mask)
{
vbi_event_handler_rec *eh, **ehp;
vbi_event_mask clear_mask;
assert (NULL != el);
clear_mask = ~event_mask;
ehp = &el->first;
while (NULL != (eh = *ehp)) {
if (0 == (eh->event_mask &= clear_mask)) {
if (0 == el->ref_count) {
*ehp = eh->next;
vbi_free (eh);
} else {
eh->remove = TRUE;
ehp = &eh->next;
}
} else {
ehp = &eh->next;
}
}
el->event_mask &= clear_mask;
}
/**
* @param el Event handler list.
* @param callback Function to be called on events.
* @param user_data User pointer passed through to the @a callback function.
*
* Removes all event handlers from the list with this @a callback and
* @a user_data. You can safely call this function from a handler removing
* itself or another handler.
*/
void _vbi_event_handler_list_remove_by_callback
(_vbi_event_handler_list * el, vbi_event_handler callback, void *user_data)
{
_vbi_event_handler_list_add (el, 0, callback, user_data);
}
/**
* @param el Event handler list.
* @param eh Event handler.
*
* Removes event handler @a eh if member of the list @a el. You can
* safely call this function from a handler removing itself or another
* handler.
*/
void
_vbi_event_handler_list_remove (_vbi_event_handler_list * el,
vbi_event_handler_rec * eh)
{
vbi_event_handler_rec *eh1, **ehp;
vbi_event_mask event_union;
assert (NULL != el);
assert (NULL != eh);
ehp = &el->first;
event_union = 0;
while (NULL != (eh1 = *ehp)) {
if (eh1 == eh) {
if (0 == el->ref_count) {
*ehp = eh1->next;
vbi_free (eh1);
} else {
eh1->remove = TRUE;
ehp = &eh1->next;
}
} else {
event_union |= eh1->event_mask;
ehp = &eh1->next;
}
}
el->event_mask = event_union;
}
/**
* @param el Event handler list.
* @param event_mask Set of events (@c VBI_EVENT_) the handler is waiting
* for, can be -1 for all and 0 for none.
* @param callback Function to be called on events.
* @param user_data User pointer passed through to the @a callback
* function.
*
* Adds a new event handler to the list. When the @a callback with @a
* user_data is already registered the function merely changes the set
* of events it will receive in the future. When the @a event_mask is
* zero the function does nothing or removes an already registered event
* handler. You can safely call this function from an event handler.
*
* Any number of handlers can be added, also different handlers for the
* same event which will be called in registration order.
*
* @return
* Pointer to opaque vbi_event_handler object, @c NULL on failure or if
* no handler has been added.
*/
vbi_event_handler_rec *
_vbi_event_handler_list_add (_vbi_event_handler_list * el,
vbi_event_mask event_mask, vbi_event_handler callback, void *user_data)
{
vbi_event_handler_rec *eh, **ehp, *found;
vbi_event_mask event_union;
assert (NULL != el);
ehp = &el->first;
event_union = 0;
found = NULL;
while (NULL != (eh = *ehp)) {
if (eh->callback == callback && eh->user_data == user_data) {
if (0 == event_mask) {
if (0 == el->ref_count) {
*ehp = eh->next;
vbi_free (eh);
} else {
eh->remove = TRUE;
ehp = &eh->next;
}
continue;
} else {
found = eh;
eh->event_mask = event_mask;
}
}
event_union |= eh->event_mask;
ehp = &eh->next;
}
if (NULL == found && 0 != event_mask) {
found = vbi_malloc (sizeof (*found));
if (NULL != found) {
CLEAR (*found);
found->event_mask = event_mask;
found->callback = callback;
found->user_data = user_data;
event_union |= event_mask;
*ehp = found;
}
}
el->event_mask = event_union;
return found;
}
void
_vbi_event_handler_list_destroy (_vbi_event_handler_list * el)
{
assert (NULL != el);
_vbi_event_handler_list_remove_by_event (el, (vbi_event_mask) - 1);
CLEAR (*el);
}
vbi_bool
_vbi_event_handler_list_init (_vbi_event_handler_list * el)
{
assert (NULL != el);
CLEAR (*el);
return TRUE;
}
/*
Local variables:
c-set-style: K&R
c-basic-offset: 8
End:
*/
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