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/*
* Copyright (C) 2001-2004 Michael H. Schimek
* Copyright (C) 2000-2003 Iaki Garca Etxebarria
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* $Id: callback.c,v 1.4 2005/07/04 21:55:52 mschimek Exp $ */
#include <assert.h>
#include <stdlib.h>
#include "callback.h"
struct _tv_callback {
tv_callback * next;
tv_callback ** prev_next;
tv_callback_fn * notify;
tv_callback_fn * destroy;
void * user_data;
unsigned int blocked;
};
void
tv_nullify_pointer (void * object,
void * user_data)
{
assert (NULL != user_data);
object = object;
* ((void **) user_data) = NULL;
}
/**
* Remove a callback function from its list. Argument is the result
* of tv_callback_add().
*
* Intended for tveng clients. Note the destroy handler is not called.
*/
void
tv_callback_remove (tv_callback * cb)
{
tv_callback *next;
if (!cb)
return;
if ((next = cb->next))
next->prev_next = cb->prev_next;
if (cb->prev_next)
*cb->prev_next = next;
free (cb);
}
void
tv_callback_delete (tv_callback * cb,
void * object)
{
assert (object != NULL);
if (!cb)
return;
if (cb->destroy)
cb->destroy (object, cb->user_data);
tv_callback_remove (cb);
}
/**
* Removes all callbacks from the list with the given notify and destroy
* functions and user_data.
*
* Intended for tveng clients. Note the destroy handler is not called.
*/
void
tv_callback_remove_all (tv_callback * list,
tv_callback_fn * notify,
tv_callback_fn * destroy,
void * user_data)
{
while (list) {
if ((NULL == user_data || list->user_data == user_data)
&& (NULL == notify || list->notify == notify)
&& (NULL == destroy || list->destroy == destroy)) {
tv_callback *next;
if ((next = list->next))
next->prev_next = list->prev_next;
if (list->prev_next)
*list->prev_next = next;
free (list);
list = next;
} else {
list = list->next;
}
}
}
void
tv_callback_delete_all (tv_callback * list,
tv_callback_fn * notify,
tv_callback_fn * destroy,
void * user_data,
void * object)
{
assert (object != NULL);
while (list) {
if ((NULL == user_data || list->user_data == user_data)
&& (NULL == notify || list->notify == notify)
&& (NULL == destroy || list->destroy == destroy)) {
tv_callback *next;
/* XXX needs ref counter? */
if (list->destroy)
list->destroy (object, list->user_data);
if ((next = list->next))
next->prev_next = list->prev_next;
if (list->prev_next)
*list->prev_next = next;
free (list);
list = next;
} else {
list = list->next;
}
}
}
/**
* Add a function to a callback list. The notify function is called
* on some event, the destroy function (if not NULL) before the list
* is deleted.
*
* Not intended to be called directly by tveng clients.
*/
tv_callback *
tv_callback_add (tv_callback ** list,
tv_callback_fn * notify,
tv_callback_fn * destroy,
void * user_data)
{
tv_callback *cb;
assert (NULL != list);
assert (NULL != notify || NULL != destroy);
for (; (cb = *list); list = &cb->next)
;
if (!(cb = calloc (1, sizeof (*cb))))
return NULL;
*list = cb;
cb->prev_next = list;
cb->notify = notify;
cb->destroy = destroy;
cb->user_data = user_data;
return cb;
}
/**
* Temporarily block calls to the notify handler.
*/
void
tv_callback_block (tv_callback * cb)
{
if (cb)
++cb->blocked;
}
void
tv_callback_block_all (tv_callback * list,
tv_callback_fn * notify,
tv_callback_fn * destroy,
void * user_data)
{
for (; list; list = list->next) {
if ((NULL == user_data || list->user_data == user_data)
&& (NULL == notify || list->notify == notify)
&& (NULL == destroy || list->destroy == destroy)) {
++list->blocked;
}
}
}
/**
* Counterpart of tv_callback_block().
*/
void
tv_callback_unblock (tv_callback * cb)
{
if (cb && cb->blocked > 0)
--cb->blocked;
}
void
tv_callback_unblock_all (tv_callback * list,
tv_callback_fn * notify,
tv_callback_fn * destroy,
void * user_data)
{
for (; list; list = list->next) {
if ((NULL == user_data || list->user_data == user_data)
&& (NULL == notify || list->notify == notify)
&& (NULL == destroy || list->destroy == destroy)) {
if (list->blocked > 0)
--list->blocked;
}
}
}
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