GenericList.cpp

From Giona

/****************************************************************************
 *This class represents a generic linked list.
 *Author: Rosario Marino
 ***************************************************************************/

#include "GenericList.h"

/*
 * Constructor
 */
GenericList::GenericList()
{
	Debug::debug("GenericList::GenericList()");
    this->head = NULL;
    this->length = 0;
    this->lastError = ERROR_NO;
}
 
/*
 * Destructor
 */
GenericList::~GenericList()
{
	Debug::debug("GenericList::~GenericList()");
    deleteList();
}

/*
 * Adds a node at the end of the list
 * Returns FALSE in case of error, TRUE otherwise
 */
bool GenericList::addNode(GenericListNode* node)
{
	Debug::debug("bool GenericList::addNode(GenericListNode* node)");
    if(node == NULL)
    {
        this->lastError = ERROR_NULL_NODE;
        Debug::debug("ERROR: ERROR_NULL_NODE");
        return false;
    }
    this->length++;
    if(this->head == NULL)
    {
        head=node;
        return true;
    }
    GenericListNode *tmp = this->head;
    while(tmp->getNext() != NULL)
        tmp = tmp->getNext();
    tmp->setNext(node);
    return true;
}

/*
 * Adds a node on the head of the list
 * Returns FALSE in case of error, TRUE otherwise
 */
bool GenericList::inHeadNode(GenericListNode* node)
{
	Debug::debug("bool GenericList::inHeadNode(GenericListNode* node)");
    if(node == NULL)
    {
    	Debug::debug("ERROR: ERROR_NULL_NODE");
        this->lastError = ERROR_NULL_NODE;
        return false;
    }
    node->setNext(this->getHead());
    this->head = node;
    this->length++;
    return true;    
}

/*
 * returns the head node of the list
 */
GenericListNode *GenericList::getHead()
{
	Debug::debug("GenericListNode *GenericList::getHead()");
    return this->head;
}

/*
 * extracts and returns the head node of the list
 */
GenericListNode *GenericList::extractHead()
{
	Debug::debug("GenericListNode *GenericList::extractHead()");
    if(this->head == NULL)
    {
    	Debug::debug("ERROR: ERROR_EMPTY_LIST");
        this->lastError = ERROR_EMPTY_LIST;
        return NULL;
    }
    GenericListNode* node = this->head;
    this->head =node->getNext();
    this->length--;
    return node;
}

/*
 * extracts the node at position idx and returns it
 */
GenericListNode* GenericList::extractNode(int idx)
{
	Debug::debug("GenericListNode* GenericList::extractNode(int idx)");
    if((idx<0)||(idx>length-1))
    {
    	Debug::debug("ERROR: ERROR_OUT_OF_RANGE_INDEX");
        this->lastError = ERROR_OUT_OF_RANGE_INDEX;
        return NULL;
    }
    if(idx==0)
        return(this->extractHead());
    GenericListNode * tmp=this->getHead();
    for(int i=1; i<idx; i++)
        tmp=tmp->getNext();
    GenericListNode* node= tmp->getNext();
    tmp->setNext(node->getNext());
    this->length--;
    return node;
}


/*
 * returns the node at position idx without extracting it from the list
 */
GenericListNode* GenericList::viewNode(int idx)
{
	Debug::debug("GenericListNode* GenericList::viewNode(int idx)");
    if((idx<0)||(idx>length-1))
    {
    	Debug::debug("ERROR: ERROR_OUT_OF_RANGE_INDEX");
        this->lastError = ERROR_OUT_OF_RANGE_INDEX;
        return NULL;
    }
    if(idx==0)
        return(this->getHead());
    GenericListNode * tmp=this->getHead();
    for(int i=1; i<=idx; i++)
        tmp=tmp->getNext();
    return tmp;
}

/*
 * Deletes the node from the list. Returns FALSE in case
 * of error, TRUE otherwise
 */ 
bool GenericList::deleteNode(GenericListNode *node)
{
	Debug::debug("bool GenericList::deleteNode(GenericListNode *node)");
    if(this->head == NULL)
    {
    	Debug::debug("ERROR: ERROR_EMPTY_LIST");
        this->lastError = ERROR_EMPTY_LIST;
        return false;
    }
    if(node == NULL)
    {
    	Debug::debug("ERROR: ERROR_NULL_NODE");
        this->lastError = ERROR_NULL_NODE;
        return false;
    }
    GenericListNode *tmp = this->head;
    if (tmp == node)
    {
        this->head = tmp->getNext();
        delete(tmp);
        this->length --;
        return true;
    }
    while((tmp->getNext() !=NULL) && (tmp->getNext() != node))
        tmp = tmp->getNext();
    if(tmp->getNext() == NULL)
    {
    	Debug::debug("ERROR: ERROR_NODE_NOT_FOUND");
        this->lastError = ERROR_NODE_NOT_FOUND;
        return false;
    }
    GenericListNode* delNode = tmp->getNext();
    tmp->setNext(delNode->getNext());
    delete(delNode);
    this->length--;
    return true;
}

/*
 * Returns last error code
 */
int GenericList::getLastError()
{
	Debug::debug("int GenericList::getLastError()");
    return this->lastError;
}

/*
 * Returns the number of list nodes
 */
int GenericList::getLength()
{
	Debug::debug("int GenericList::getLength()");
    return this->length;
}

/*
 * (Private) deletes all list nodes 
 */
void GenericList::deleteList()
{
	Debug::debug("void GenericList::deleteList()");
    GenericListNode * tmp = this->head;
    while(tmp)
    {
        GenericListNode* tmpNext=tmp->getNext();
        delete(tmp);
        tmp = tmpNext;
    }
}

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