/**************************************************************************
* Dequeue
* ------------------------------------------------------------------------
* Removes the first node from the list
**************************************************************************/
Customer CustomerList::Dequeue()
{
Node<Customer>* temp;
Customer tempCustomer;
if(isEmpty())
{
QMessageBox messageBox;
messageBox.critical(0,"Error","**Cannot dequeue empty list**");
messageBox.setFixedSize(500,200);
}
else
{
//Assigns temp to head
temp = _head;
_head = _head->GetNext();
//Decrements the _nodeCount
DecrementCount();
//Calls Orphan to set all pointers to NULL
temp->Orphan();
tempCustomer = temp->GetData();
delete temp;
temp = NULL;
}
return tempCustomer;
}
CRefCntMem& CRefCntMem::operator=(const CRefCntMem& ref)
{
// Assignment
DecrementCount(); // if m_ptr exists, no longer pointing to it
m_ptr = ref.m_ptr;
IncrementCount();
return *this;
}
void CRefCntMem::ReAllocate(int nBytes, void *memory, bool deleteWhenDone,
void (*deleteFunction)(void *ptr))
{
// Allocate/deallocate memory
DecrementCount();
if (memory)
{
m_ptr = new CRefCntMemPtr;
m_ptr->m_nBytes = nBytes;
m_ptr->m_memory = memory;
m_ptr->m_deleteWhenDone = deleteWhenDone;
m_ptr->m_refCnt = 1;
m_ptr->m_delFn = deleteFunction;
}
else
m_ptr = 0; // don't bother storing pointer to null memory
}
void CustomerList::RemoveCustomer(Customer &someCustomer)
{
Node<Customer> * traversePtr;
Node<Customer> * actionPtr;
if(isEmpty())
{
// cout << "Can't Dequeue an empty list" << endl;
throw EmptyList();
}
traversePtr = _head;
int index = 0;
while (index < _listLimit && traversePtr != NULL && !(traversePtr->GetData() == someCustomer))
{
traversePtr = traversePtr->GetNext();
index++;
}
// overloaded operator
if (traversePtr->GetData() == someCustomer)
{
// head deletion
if (traversePtr == _head)
{
Dequeue();
}
// end deletion
else if (traversePtr == _tail)
{
_tail = _tail->GetPrevious();
_tail->SetNext(NULL);
// _tail->_next = NULL;
traversePtr->Orphan();
delete traversePtr;
//Decrements the _nodeCount
DecrementCount();
}
// middle deletion
else
{
actionPtr = traversePtr->GetPrevious();
actionPtr->SetNext(traversePtr->GetNext());
traversePtr->SetNext(traversePtr->GetNext());
traversePtr->SetPrevious(actionPtr);
traversePtr->Orphan();
delete traversePtr;
//Decrements the _nodeCount
DecrementCount();
}
}
if (index == _listLimit && traversePtr == NULL)
{
// throw exception class if not found.
traversePtr = NULL;
throw NotFound();
}
}
CRefCntMem::~CRefCntMem()
{
// Destructor
DecrementCount();
m_ptr = 0; // not necessary, just for debugging
}
