dom/xslt/base/txList.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "txList.h"
   7
   8 //----------------------------/
   9 //- Implementation of txList -/
  10 //----------------------------/
  11
  12 /**
  13  * Default constructor for a txList;
  14  **/
  15
  16 txList::txList() {
  17   firstItem = 0;
  18   lastItem = 0;
  19   itemCount = 0;
  20 }  //-- txList;
  21
  22 /**
  23  * txList destructor, cleans up ListItems, but will not delete the Object
  24  * references
  25  */
  26 txList::~txList() { clear(); }  //-- ~txList
  27
  28 void txList::add(void* objPtr) { insertBefore(objPtr, nullptr); }  //-- add
  29
  30 /**
  31  * Returns the number of items in this txList
  32  **/
  33 int32_t List::getLength() { return itemCount; }  //-- getLength
  34
  35 /**
  36  * Inserts the given Object pointer as the item just after refItem.
  37  * If refItem is a null pointer the Object will be inserted at the
  38  * beginning of the txList (ie, insert after nothing).
  39  * This method assumes refItem is a member of this list, and since this
  40  * is a private method, I feel that's a valid assumption
  41  **/
  42 void txList::insertAfter(void* objPtr, ListItem* refItem) {
  43   insertBefore(objPtr, refItem ? refItem->nextItem : firstItem);
  44 }  //-- insertAfter
  45
  46 /**
  47  * Inserts the given Object pointer as the item just before refItem.
  48  * If refItem is a null pointer the Object will be inserted at the
  49  * end of the txList (ie, insert before nothing).
  50  * This method assumes refItem is a member of this list, and since this
  51  * is a private method, I feel that's a valid assumption
  52  **/
  53 void txList::insertBefore(void* objPtr, ListItem* refItem) {
  54   ListItem* item = new ListItem;
  55   item->objPtr = objPtr;
  56   item->nextItem = 0;
  57   item->prevItem = 0;
  58
  59   //-- if refItem == null insert at end
  60   if (!refItem) {
  61     //-- add to back of list
  62     if (lastItem) {
  63       lastItem->nextItem = item;
  64       item->prevItem = lastItem;
  65     }
  66     lastItem = item;
  67     if (!firstItem) firstItem = item;
  68   } else {
  69     //-- insert before given item
  70     item->nextItem = refItem;
  71     item->prevItem = refItem->prevItem;
  72     refItem->prevItem = item;
  73
  74     if (item->prevItem)
  75       item->prevItem->nextItem = item;
  76     else
  77       firstItem = item;
  78   }
  79
  80   // increase the item count
  81   ++itemCount;
  82 }  //-- insertBefore
  83
  84 txList::ListItem* txList::remove(ListItem* item) {
  85   if (!item) return item;
  86
  87   //-- adjust the previous item's next pointer
  88   if (item->prevItem) {
  89     item->prevItem->nextItem = item->nextItem;
  90   }
  91   //-- adjust the next item's previous pointer
  92   if (item->nextItem) {
  93     item->nextItem->prevItem = item->prevItem;
  94   }
  95
  96   //-- adjust first and last items
  97   if (item == firstItem) firstItem = item->nextItem;
  98   if (item == lastItem) lastItem = item->prevItem;
  99
 100   //-- decrease Item count
 101   --itemCount;
 102   return item;
 103 }  //-- remove
 104
 105 void txList::clear() {
 106   ListItem* item = firstItem;
 107   while (item) {
 108     ListItem* tItem = item;
 109     item = item->nextItem;
 110     delete tItem;
 111   }
 112   firstItem = 0;
 113   lastItem = 0;
 114   itemCount = 0;
 115 }
 116
 117 //------------------------------------/
 118 //- Implementation of txListIterator -/
 119 //------------------------------------/
 120
 121 /**
 122  * Creates a new txListIterator for the given txList
 123  * @param list, the txList to create an Iterator for
 124  **/
 125 txListIterator::txListIterator(txList* list) {
 126   this->list = list;
 127   currentItem = 0;
 128   atEndOfList = false;
 129 }  //-- txListIterator
 130
 131 /**
 132  * Adds the Object pointer to the txList pointed to by this txListIterator.
 133  * The Object pointer is inserted as the next item in the txList
 134  * based on the current position within the txList
 135  * @param objPtr the Object pointer to add to the list
 136  **/
 137 void txListIterator::addAfter(void* objPtr) {
 138   if (currentItem || !atEndOfList) {
 139     list->insertAfter(objPtr, currentItem);
 140   } else {
 141     list->insertBefore(objPtr, nullptr);
 142   }
 143 }  //-- addAfter
 144
 145 /**
 146  * Adds the Object pointer to the txList pointed to by this txListIterator.
 147  * The Object pointer is inserted as the previous item in the txList
 148  * based on the current position within the txList
 149  * @param objPtr the Object pointer to add to the list
 150  **/
 151 void txListIterator::addBefore(void* objPtr) {
 152   if (currentItem || atEndOfList) {
 153     list->insertBefore(objPtr, currentItem);
 154   } else {
 155     list->insertAfter(objPtr, nullptr);
 156   }
 157 }  //-- addBefore
 158
 159 /**
 160  * Returns true if a successful call to the next() method can be made
 161  * @return true if a successful call to the next() method can be made,
 162  * otherwise false
 163  **/
 164 bool txListIterator::hasNext() {
 165   bool hasNext = false;
 166   if (currentItem)
 167     hasNext = (currentItem->nextItem != 0);
 168   else if (!atEndOfList)
 169     hasNext = (list->firstItem != 0);
 170
 171   return hasNext;
 172 }  //-- hasNext
 173
 174 /**
 175  * Returns the next Object pointer in the list
 176  **/
 177 void* txListIterator::next() {
 178   void* obj = 0;
 179   if (currentItem)
 180     currentItem = currentItem->nextItem;
 181   else if (!atEndOfList)
 182     currentItem = list->firstItem;
 183
 184   if (currentItem)
 185     obj = currentItem->objPtr;
 186   else
 187     atEndOfList = true;
 188
 189   return obj;
 190 }  //-- next
 191
 192 /**
 193  * Returns the previous Object in the list
 194  **/
 195 void* txListIterator::previous() {
 196   void* obj = 0;
 197
 198   if (currentItem)
 199     currentItem = currentItem->prevItem;
 200   else if (atEndOfList)
 201     currentItem = list->lastItem;
 202
 203   if (currentItem) obj = currentItem->objPtr;
 204
 205   atEndOfList = false;
 206
 207   return obj;
 208 }  //-- previous
 209
 210 /**
 211  * Returns the current Object
 212  **/
 213 void* txListIterator::current() {
 214   if (currentItem) return currentItem->objPtr;
 215
 216   return 0;
 217 }  //-- current
 218
 219 /**
 220  * Removes the Object last returned by the next() or previous() methods;
 221  * @return the removed Object pointer
 222  **/
 223 void* txListIterator::remove() {
 224   void* obj = 0;
 225   if (currentItem) {
 226     obj = currentItem->objPtr;
 227     txList::ListItem* item = currentItem;
 228     previous();  //-- make previous item the current item
 229     list->remove(item);
 230     delete item;
 231   }
 232   return obj;
 233 }  //-- remove
 234
 235 /**
 236  * Resets the current location within the txList to the beginning of the txList
 237  **/
 238 void txListIterator::reset() {
 239   atEndOfList = false;
 240   currentItem = 0;
 241 }  //-- reset
 242
 243 /**
 244  * Move the iterator to right after the last element
 245  **/
 246 void txListIterator::resetToEnd() {
 247   atEndOfList = true;
 248   currentItem = 0;
 249 }  //-- moveToEnd