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cdesktop/cde/lib/DtMmdb/dti_cc/CC_Listbase.C

272 lines
6.9 KiB
C

/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these libraries and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/*
* $TOG: CC_Listbase.C /main/4 1998/04/17 11:44:10 mgreess $
* $TOG: CC_Listbase.C /main/4 1998/04/17 11:44:10 mgreess $
* $TOG: CC_Listbase.C /main/4 1998/04/17 11:44:10 mgreess $
* $TOG: CC_Listbase.C /main/4 1998/04/17 11:44:10 mgreess $
*
* Copyright (c) 1993 HAL Computer Systems International, Ltd.
* All rights reserved. Unpublished -- rights reserved under
* the Copyright Laws of the United States. USE OF A COPYRIGHT
* NOTICE IS PRECAUTIONARY ONLY AND DOES NOT IMPLY PUBLICATION
* OR DISCLOSURE.
*
* THIS SOFTWARE CONTAINS CONFIDENTIAL INFORMATION AND TRADE
* SECRETS OF HAL COMPUTER SYSTEMS INTERNATIONAL, LTD. USE,
* DISCLOSURE, OR REPRODUCTION IS PROHIBITED WITHOUT THE
* PRIOR EXPRESS WRITTEN PERMISSION OF HAL COMPUTER SYSTEMS
* INTERNATIONAL, LTD.
*
* RESTRICTED RIGHTS LEGEND
* Use, duplication, or disclosure by the Government is subject
* to the restrictions as set forth in subparagraph (c)(l)(ii)
* of the Rights in Technical Data and Computer Software clause
* at DFARS 252.227-7013.
*
* HAL COMPUTER SYSTEMS INTERNATIONAL, LTD.
* 1315 Dell Avenue
* Campbell, CA 95008
*
*/
#include "dti_excs/Exceptions.hh"
#include "cc_exceptions.h"
#include "CC_Listbase.h"
// /////////////////////////////////////////////////////////////////
// CC_Listbase::insert - append a new link to the end of the list
// /////////////////////////////////////////////////////////////////
void
CC_Listbase::insert (CC_Link_base *element)
{
if (!element) {
throw(CASTCCEXCEPT ccException());
}
if (!f_tail) {
f_tail = f_head = element;
}
else {
f_tail->f_next = element;
element->f_prev = f_tail;
f_tail = element;
}
f_length++;
}
// /////////////////////////////////////////////////////////////////
// CC_Listbase::insert - insert a new link into the list
// /////////////////////////////////////////////////////////////////
void
CC_Listbase::prepend (CC_Link_base *element)
{
if ( !element ) {
throw(CASTCCEXCEPT ccException());
}
if ( !f_head ) {
f_head = element;
}
else {
element->f_next = f_head;
f_head->f_prev = element;
f_head = element;
}
if (f_tail == NULL)
f_tail = element;
f_length++;
}
// /////////////////////////////////////////////////////////////////
// CC_Listbase::remove - remove element pointed to by iterator
// /////////////////////////////////////////////////////////////////
CC_Link_base *
CC_Listbase::remove (CC_List_Iterator_base &iterator)
{
// Make sure the iterator points to this this.
if (iterator.f_list != this)
throw (CASTCCEXCEPT ccException());
// Make sure the iterator is pointing to an element.
if (iterator.f_current == NULL)
return(NULL);
// NOTE: If two iterators are active in the list at the same time
// it is possible to blow away an element that another iterator
// is pointing at (either previous or current). We could make this
// safer by only marking elements as deleted for now, then actually
// delete the items when there are no more iterators pointing at it.
// 19:41 22-Jul-93 DJB
// Link around the link we're removing.
if (iterator.f_previous != NULL) {
iterator.f_previous->f_next = iterator.f_current->f_next;
if ( f_tail != iterator.f_current ) {
iterator.f_current->f_next->f_prev = iterator.f_previous;
}
}
else { // must be at the head
f_head = iterator.f_current->f_next;
if ( f_head ) {
f_head->f_prev = NULL;
}
}
if (iterator.f_current == f_tail) {
f_tail = iterator.f_previous;
if ( f_tail ) {
f_tail->f_next = NULL;
}
}
// Increment the iterator.
CC_Link_base *entry = iterator.f_current;
iterator.f_current = iterator.f_current->f_next;
f_length--;
return (entry);
}
CC_Link_base *
CC_Listbase::removeFirst()
{
if ( f_head ) {
CC_Link_base *remove_item = f_head;
f_head = f_head->f_next;
remove_item->f_next = NULL;
if ( f_head ) {
f_head->f_prev = NULL;
}
if ( f_tail == remove_item ) { /* only one item on the list */
f_tail = NULL;
}
f_length--;
return(remove_item);
}
return(NULL);
}
//------------------------------------------------------------------
CC_Link_base *
CC_Listbase::removeLast()
{
if ( f_tail ) {
CC_Link_base *remove_item = f_tail;
f_tail = f_tail->f_prev;
remove_item->f_prev = NULL;
if ( f_tail ) {
f_tail->f_next = NULL;
}
if ( f_head == remove_item ) { // one item left on the list
f_head = NULL;
}
f_length--;
return(remove_item);
}
return(NULL);
}
// /////////////////////////////////////////////////////////////////
// CC_List_Iterator::CC_List_Iterator - class constructor
// /////////////////////////////////////////////////////////////////
CC_List_Iterator_base::CC_List_Iterator_base (CC_Listbase *list)
: f_list (list)
{
if ( !list ) {
throw(CASTCCEXCEPT ccException());
}
reset();
}
// /////////////////////////////////////////////////////////////////
// CC_List_Iterator::reset - reset the iterator to the list start
// /////////////////////////////////////////////////////////////////
void
CC_List_Iterator_base::reset()
{
f_current = f_previous = NULL;
}
// /////////////////////////////////////////////////////////////////
// CC_List_Iterator:: operator ++ - increment the list iterator
// /////////////////////////////////////////////////////////////////
CC_Boolean
CC_List_Iterator_base::operator++()
{
if (!f_current) { // havn't touched the first element
f_current = f_list->first();
f_previous = NULL;
if ( f_current ) return ( TRUE );
else return(FALSE);
}
f_previous = f_current;
f_current = f_current->f_next;
if ( f_current ) {
return(TRUE);
}
else {
return(FALSE);
}
}
CC_Boolean
CC_List_Iterator_base::operator--()
{
if (!f_current) {
return(FALSE);
}
f_current = f_previous;
if ( f_previous ) {
f_previous = f_previous->f_prev;
}
if ( f_current ) { return(TRUE); }
else { return(FALSE); }
}