public TreeNode nextElement() {
Enumeration enumer = stack.peek();
TreeNode node = (TreeNode) enumer.nextElement();
Enumeration children = node.children();
if (!enumer.hasMoreElements()) {
stack.pop();
}
if (children.hasMoreElements()) {
stack.push(children);
}
return node;
}
public TreeNode nextElement() {
try {
return stack.pop();
} catch (EmptyStackException e) {
throw new NoSuchElementException("No more elements");
}
}
public PathBetweenNodesEnumeration(TreeNode ancestor, TreeNode descendant) {
super();
if (ancestor == null || descendant == null) {
throw new IllegalArgumentException("argument is null");
}
TreeNode current;
stack = new Stack<TreeNode>();
stack.push(descendant);
current = descendant;
while (current != ancestor) {
current = current.getParent();
if (current == null && descendant != ancestor) {
throw new IllegalArgumentException(
"node " + ancestor + " is not an ancestor of " + descendant);
}
stack.push(current);
}
}
public boolean hasMoreElements() {
return stack.size() > 0;
}
public boolean hasMoreElements() {
return (!stack.empty() && stack.peek().hasMoreElements());
}
public PreorderEnumeration(TreeNode rootNode) {
super();
Vector<TreeNode> v = new Vector<TreeNode>(1);
v.addElement(rootNode); // PENDING: don't really need a vector
stack.push(v.elements());
}