tor-browser

txList.cpp (6345B)

---

/* -*- 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