public IEnumerator <T> GetEnumerator()
{
ListItemCustom <T> currentNode = this.firstElement;
while (currentNode != null)
{
yield return(currentNode.Value);
currentNode = currentNode.NextItem;
}
}
public T Dequeue()
{
if (this.Count == 0)
{
throw new InvalidOperationException("The queue is empty.");
}
this.firstElement = this.firstElement.NextItem;
if (this.Count == 1)
{
this.lastElement = null;
}
this.Count--;
return(this.firstElement.Value);
}
private ListItemCustom <T> GetPrev(ListItemCustom <T> item)
{
ListItemCustom <T> currentNode = this.FirstItem;
while (currentNode.NextItem != null)
{
if (currentNode.NextItem == item)
{
return(currentNode);
}
currentNode = currentNode.NextItem;
}
throw new NullReferenceException();
}
public void AddLast(ListItemCustom <T> item)
{
if (this.Count == 0)
{
this.FirstItem = item;
this.LastItem = item;
}
else
{
this.LastItem.NextItem = item;
this.LastItem = item;
}
this.Count++;
}
public void Enqueue(T item)
{
ListItemCustom <T> newNode = new ListItemCustom <T>(item);
if (this.Count == 0)
{
this.firstElement = newNode;
}
else
{
this.lastElement.NextItem = newNode;
}
this.lastElement = newNode;
this.Count++;
}
public void AddBefore(ListItemCustom <T> node, ListItemCustom <T> newItem)
{
if (node == null || newItem == null)
{
throw new ArgumentNullException();
}
if (node == this.FirstItem)
{
this.AddFirst(newItem);
return;
}
GetPrev(node).NextItem = newItem;
newItem.NextItem = node;
this.Count++;
}
public void AddAfter(ListItemCustom <T> node, ListItemCustom <T> newItem)
{
if (node == null || newItem == null)
{
throw new ArgumentNullException();
}
if (node.NextItem == null)
{
this.AddLast(newItem);
return;
}
newItem.NextItem = node.NextItem;
node.NextItem = newItem;
this.Count++;
}
public void Clear()
{
this.firstElement = null;
this.lastElement = null;
this.Count = 0;
}
public void AddBefore(ListItemCustom <T> node, T newItem)
{
ListItemCustom <T> newNode = new ListItemCustom <T>(newItem);
this.AddBefore(node, newNode);
}
public void AddLast(T item)
{
ListItemCustom <T> newItem = new ListItemCustom <T>(item);
this.AddLast(newItem);
}
