/// <summary>
/// Remove item from list
/// </summary>
/// <param name="item">item to remove</param>
/// <returns>Item, if it was successfully removed</returns>
public T Remove(T item)
{
lock (_lock)
{
int i = 0;
ParentAwareNode <T> previousNode = null;
ParentAwareNode <T> currentNode = _head;
while (i < _length && !item.Equals(currentNode.Value))
{
previousNode = currentNode;
currentNode = currentNode.Next() as ParentAwareNode <T>;
i++;
}
if (i == _length)
{
throw new IndexOutOfRangeException();
}
item = currentNode.Value;
if (previousNode == null)
{
_head = currentNode.Next() as ParentAwareNode <T>;
}
else
{
previousNode.SetChild(currentNode.Next());
}
_length--;
}
return(item);
}
/// <summary>
/// Removes item at specified index
/// </summary>
/// <param name="index">index of item to remove</param>
/// <returns>item which was removed</returns>
public T RemoveAt(int index)
{
if (index > _length - 1)
{
throw new IndexOutOfRangeException();
}
T item;
lock (_lock)
{
int i = 0;
ParentAwareNode <T> previousNode = null;
ParentAwareNode <T> currentNode = _head;
while (i < index)
{
previousNode = currentNode;
currentNode = currentNode.Next() as ParentAwareNode <T>;
i++;
}
item = currentNode.Value;
if (previousNode == null)
{
_head = currentNode.Next() as ParentAwareNode <T>;
}
else
{
previousNode.SetChild(currentNode.Next());
}
_length--;
}
return(item);
}
/// <summary>
/// Get Item at specified index
/// </summary>
/// <param name="index">the index to return item</param>
/// <returns>item at the specified index</returns>
public T Get(int index)
{
if (index > _length - 1)
{
throw new IndexOutOfRangeException();
}
ParentAwareNode <T> node = _head;
int i = 0;
int midpoint = GetMidPointIndex();
if (index > midpoint)
{
node = _last;
// find starting at end
i = _length - 1;
while (i > index)
{
node = node.Previous() as ParentAwareNode <T>;
i--;
}
}
else
{
while (i < index)
{
node = node.Next() as ParentAwareNode <T>;
i++;
}
}
return(node.Value);
}
/// <summary>
/// Remove item from list
/// </summary>
/// <param name="item">item to remove</param>
/// <returns>Item, if it was successfully removed</returns>
public T Remove(T item)
{
lock (_lock)
{
ParentAwareNode <T> currentNode = _head;
while (
currentNode != null && // if currentNode is null, we are at the end
((item == null && currentNode.Value != null) || //if item is null and current value is null we found it
(item != null && !item.Equals(currentNode.Value))) // if item is not null and item equals current value we found it
)
{
currentNode = currentNode.Next() as ParentAwareNode <T>;
}
if (currentNode == null)
{
throw new IndexOutOfRangeException();
}
item = currentNode.Value;
DeleteNode(currentNode);
}
return(item);
}
/// <summary>
/// Returns the tail of the list
/// </summary>
/// <returns>The items after the first item in the list</returns>
public List <T> Tail()
{
if (_length < 2)
{
return(new LinkedList <T>());
}
return(new LinkedList <T>(_head.Next() as ParentAwareNode <T>, _length - 1));
}
private void DeleteNode(ParentAwareNode <T> node)
{
if (node.Previous() == null)
{
_head = node;
}
else
{
(node.Previous() as IChildableNode <T>).SetChild(node.Next());
}
if (node.Next() == null)
{
_last = node;
}
else
{
(node.Next() as ParentAwareNode <T>).SetParent(node.Previous());
}
_length--;
}
/// <summary>
/// Get Item at specified index
/// </summary>
/// <param name="index">the index to return item</param>
/// <returns>item at the specified index</returns>
public T Get(int index)
{
if (index > _length - 1)
{
throw new IndexOutOfRangeException();
}
ParentAwareNode <T> node = _head;
int i = 0;
while (i < index)
{
node = node.Next() as ParentAwareNode <T>;
i++;
}
return(node.Value);
}
/// <summary>
/// Get index of the item
/// </summary>
/// <param name="item">Item to return index</param>
/// <returns>index of the item, if it is in the list.
/// If item is not in the list, returns -1
/// </returns>
public int IndexOf(T item)
{
if (_length == 0)
{
return(-1);
}
int index = 0;
ParentAwareNode <T> currentNode = _head;
while (currentNode != null)
{
if (item.Equals(currentNode.Value))
{
return(index);
}
index++;
currentNode = currentNode.Next() as ParentAwareNode <T>;
}
return(-1);
}