/**
* Return the Nth immediate child of this node, or null if the index is out of bounds. Use to
* implement NodeList.item().
*
* @param index int
*/
private Node nodeListItem(int index) {
if (fNodeListCache == null) {
// get rid of trivial case
if (firstChild == lastChild()) {
return index == 0 ? firstChild : null;
}
// otherwise request a cache object
fNodeListCache = ownerDocument.getNodeListCache(this);
}
int i = fNodeListCache.fChildIndex;
ChildNode n = fNodeListCache.fChild;
boolean firstAccess = true;
// short way
if (i != -1 && n != null) {
firstAccess = false;
if (i < index) {
while (i < index && n != null) {
i++;
n = n.nextSibling;
}
} else if (i > index) {
while (i > index && n != null) {
i--;
n = n.previousSibling();
}
}
} else {
// long way
if (index < 0) {
return null;
}
n = firstChild;
for (i = 0; i < index && n != null; i++) {
n = n.nextSibling;
}
}
// release cache if reaching last child or first child
if (!firstAccess && (n == firstChild || n == lastChild())) {
fNodeListCache.fChildIndex = -1;
fNodeListCache.fChild = null;
ownerDocument.freeNodeListCache(fNodeListCache);
// we can keep using the cache until it is actually reused
// fNodeListCache will be nulled by the pool (document) if that
// happens.
// fNodeListCache = null;
} else {
// otherwise update it
fNodeListCache.fChildIndex = i;
fNodeListCache.fChild = n;
}
return n;
} // nodeListItem(int):Node
