//
// System.Xml.XmlNodeList
//
// Author:
// Kral Ferch <kral_ferch@hotmail.com>
//
// (C) 2002 Kral Ferch
//
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Collections;
namespace System.Xml{
internal class XmlNodeListChildren : XmlNodeList
{
#region Enumerator
private class Enumerator : IEnumerator
{
IHasXmlChildNode parent;
XmlLinkedNode currentChild;
bool passedLastNode;
internal Enumerator (IHasXmlChildNode parent)
{
currentChild = null;
this.parent = parent;
passedLastNode = false;
}
public virtual object Current {
get {
if ((currentChild == null) ||
(parent.LastLinkedChild == null) ||
(passedLastNode == true))
throw new InvalidOperationException();
return currentChild;
}
}
public virtual bool MoveNext()
{
bool movedNext = true;
if (parent.LastLinkedChild == null) {
movedNext = false;
}
else if (currentChild == null) {
currentChild = parent.LastLinkedChild.NextLinkedSibling;
}
else {
if (Object.ReferenceEquals(currentChild, parent.LastLinkedChild)) {
movedNext = false;
passedLastNode = true;
}
else {
currentChild = currentChild.NextLinkedSibling;
}
}
return movedNext;
}
public virtual void Reset()
{
currentChild = null;
}
}
#endregion
#region Fields
IHasXmlChildNode parent;
#endregion
#region Constructors
public XmlNodeListChildren(IHasXmlChildNode parent)
{
this.parent = parent;
}
#endregion
#region Properties
public override int Count {
get {
int count = 0;
if (parent.LastLinkedChild != null) {
XmlLinkedNode currentChild = parent.LastLinkedChild.NextLinkedSibling;
count = 1;
while (!Object.ReferenceEquals(currentChild, parent.LastLinkedChild)) {
currentChild = currentChild.NextLinkedSibling;
count++;
}
}
return count;
}
}
#endregion
#region Methods
public override IEnumerator GetEnumerator ()
{
return new Enumerator(parent);
}
public override XmlNode Item (int index)
{
XmlNode requestedNode = null;
// Return null if index is out of range. by DOM design.
if (Count <= index)
return null;
// Instead of checking for && index < Count which has to walk
// the whole list to get a count, we'll just keep a count since
// we have to walk the list anyways to get to index.
if ((index >= 0) && (parent.LastLinkedChild != null)) {
XmlLinkedNode currentChild = parent.LastLinkedChild.NextLinkedSibling;
int count = 0;
while ((count < index) && !Object.ReferenceEquals(currentChild, parent.LastLinkedChild))
{
currentChild = currentChild.NextLinkedSibling;
count++;
}
if (count == index) {
requestedNode = currentChild;
}
}
return requestedNode;
}
#endregion
}
}
|