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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "txList.h"
//----------------------------/
//- Implementation of txList -/
//----------------------------/
/**
* Default constructor for a txList;
**/
txList::txList() {
firstItem = 0;
lastItem = 0;
itemCount = 0;
} //-- txList;
/**
* txList destructor, cleans up ListItems, but will not delete the Object
* references
*/
txList::~txList() { clear(); } //-- ~txList
void txList::add(void* objPtr) { insertBefore(objPtr, nullptr); } //-- add
/**
* Returns the number of items in this txList
**/
int32_t List::getLength() { return itemCount; } //-- getLength
/**
* Inserts the given Object pointer as the item just after refItem.
* If refItem is a null pointer the Object will be inserted at the
* beginning of the txList (ie, insert after nothing).
* This method assumes refItem is a member of this list, and since this
* is a private method, I feel that's a valid assumption
**/
void txList::insertAfter(void* objPtr, ListItem* refItem) {
insertBefore(objPtr, refItem ? refItem->nextItem : firstItem);
} //-- insertAfter
/**
* Inserts the given Object pointer as the item just before refItem.
* If refItem is a null pointer the Object will be inserted at the
* end of the txList (ie, insert before nothing).
* This method assumes refItem is a member of this list, and since this
* is a private method, I feel that's a valid assumption
**/
void txList::insertBefore(void* objPtr, ListItem* refItem) {
ListItem* item = new ListItem;
item->objPtr = objPtr;
item->nextItem = 0;
item->prevItem = 0;
//-- if refItem == null insert at end
if (!refItem) {
//-- add to back of list
if (lastItem) {
lastItem->nextItem = item;
item->prevItem = lastItem;
}
lastItem = item;
if (!firstItem) firstItem = item;
} else {
//-- insert before given item
item->nextItem = refItem;
item->prevItem = refItem->prevItem;
refItem->prevItem = item;
if (item->prevItem)
item->prevItem->nextItem = item;
else
firstItem = item;
}
// increase the item count
++itemCount;
} //-- insertBefore
txList::ListItem* txList::remove(ListItem* item) {
if (!item) return item;
//-- adjust the previous item's next pointer
if (item->prevItem) {
item->prevItem->nextItem = item->nextItem;
}
//-- adjust the next item's previous pointer
if (item->nextItem) {
item->nextItem->prevItem = item->prevItem;
}
//-- adjust first and last items
if (item == firstItem) firstItem = item->nextItem;
if (item == lastItem) lastItem = item->prevItem;
//-- decrease Item count
--itemCount;
return item;
} //-- remove
void txList::clear() {
ListItem* item = firstItem;
while (item) {
ListItem* tItem = item;
item = item->nextItem;
delete tItem;
}
firstItem = 0;
lastItem = 0;
itemCount = 0;
}
//------------------------------------/
//- Implementation of txListIterator -/
//------------------------------------/
/**
* Creates a new txListIterator for the given txList
* @param list, the txList to create an Iterator for
**/
txListIterator::txListIterator(txList* list) {
this->list = list;
currentItem = 0;
atEndOfList = false;
} //-- txListIterator
/**
* Adds the Object pointer to the txList pointed to by this txListIterator.
* The Object pointer is inserted as the next item in the txList
* based on the current position within the txList
* @param objPtr the Object pointer to add to the list
**/
void txListIterator::addAfter(void* objPtr) {
if (currentItem || !atEndOfList) {
list->insertAfter(objPtr, currentItem);
} else {
list->insertBefore(objPtr, nullptr);
}
} //-- addAfter
/**
* Adds the Object pointer to the txList pointed to by this txListIterator.
* The Object pointer is inserted as the previous item in the txList
* based on the current position within the txList
* @param objPtr the Object pointer to add to the list
**/
void txListIterator::addBefore(void* objPtr) {
if (currentItem || atEndOfList) {
list->insertBefore(objPtr, currentItem);
} else {
list->insertAfter(objPtr, nullptr);
}
} //-- addBefore
/**
* Returns true if a successful call to the next() method can be made
* @return true if a successful call to the next() method can be made,
* otherwise false
**/
bool txListIterator::hasNext() {
bool hasNext = false;
if (currentItem)
hasNext = (currentItem->nextItem != 0);
else if (!atEndOfList)
hasNext = (list->firstItem != 0);
return hasNext;
} //-- hasNext
/**
* Returns the next Object pointer in the list
**/
void* txListIterator::next() {
void* obj = 0;
if (currentItem)
currentItem = currentItem->nextItem;
else if (!atEndOfList)
currentItem = list->firstItem;
if (currentItem)
obj = currentItem->objPtr;
else
atEndOfList = true;
return obj;
} //-- next
/**
* Returns the previous Object in the list
**/
void* txListIterator::previous() {
void* obj = 0;
if (currentItem)
currentItem = currentItem->prevItem;
else if (atEndOfList)
currentItem = list->lastItem;
if (currentItem) obj = currentItem->objPtr;
atEndOfList = false;
return obj;
} //-- previous
/**
* Returns the current Object
**/
void* txListIterator::current() {
if (currentItem) return currentItem->objPtr;
return 0;
} //-- current
/**
* Removes the Object last returned by the next() or previous() methods;
* @return the removed Object pointer
**/
void* txListIterator::remove() {
void* obj = 0;
if (currentItem) {
obj = currentItem->objPtr;
txList::ListItem* item = currentItem;
previous(); //-- make previous item the current item
list->remove(item);
delete item;
}
return obj;
} //-- remove
/**
* Resets the current location within the txList to the beginning of the txList
**/
void txListIterator::reset() {
atEndOfList = false;
currentItem = 0;
} //-- reset
/**
* Move the iterator to right after the last element
**/
void txListIterator::resetToEnd() {
atEndOfList = true;
currentItem = 0;
} //-- moveToEnd
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