/// <summary>
/// Adds the data to a new node in the linked list between the nodes specified
/// </summary>
/// <param name="data">Data to add to the list</param>
/// <param name="previous">A pointer to the node that will come before data's node</param>
/// <param name="next">A pointer to the node that will come after the data's node</param>
private void Link(T data, Node <T> previous, Node <T> next)
{
Node <T> newNode = new Node <T>(data, previous, next);
previous.SetNext(newNode);
next.SetPrevious(newNode);
size++;
}
/// <summary>
/// Removes the specified node from the linked list
/// </summary>
/// <param name="node">The node to be removed</param>
/// <returns>Data from the node being removed</returns>
private T Unlink(Node <T> node)
{
Node <T> previous = node.GetPrevious();
Node <T> next = node.GetNext();
previous.SetNext(next);
next.SetPrevious(previous);
size--;
return(node.GetData());
}
/// <summary>
/// Adds a new node containing the data provided to the linked list at the tail
/// </summary>
/// <param name="data">The data to add</param>
private void LinkTail(T data)
{
Node <T> toAdd = new Node <T>(data, tail, null);
// Not in diagram
tail.SetNext(toAdd);
tail = toAdd;
size++;
}
public void TestSetNext()
{
Employee emp1 = new Employee(1);
Employee emp2 = new Employee(2);
Employee emp3 = new Employee(3);
Node <Employee> node1 = new Node <Employee>(emp1);
Node <Employee> node2 = new Node <Employee>(emp2);
Node <Employee> testNode = new Node <Employee>(emp3, node1, null);
testNode.SetNext(node2);
Assert.That(testNode.GetNext(), Is.EqualTo(node2));
}
/// <summary>
/// Remove the node at the tail of the linked list and return the data it contains
/// </summary>
/// <returns>The data stored in the node being removed</returns>
private T UnlinkTail()
{
Node <T> oldTail = tail;
tail = tail.GetPrevious();
tail.SetNext(null);
size--;
return(oldTail.GetData());
}
/// <summary>
/// Adds the node to the head when null if not adds it after the head
/// </summary>
/// <param name="data">The node to be added</param>
private void LinkHead(T data)
{
Node <T> toAdd = new Node <T>(data);
// Determine if the head is null
if (head != null)
{
head.SetPrevious(toAdd);
toAdd.SetNext(head);
}
head = toAdd;
// Determine if the linked list is empty and make the tail also the head
if (size == 0)
{
tail = head;
}
size++;
}
