--- /dev/null
+
+package net.pterodactylus.util.data;
+
+import java.util.Iterator;
+
+/**
+ * A node that can be stored in a {@link Tree}. A node has exactly one parent
+ * (which is <code>null</code> if the node is the {@link Tree#getRootNode()}
+ * of the tree) and an arbitrary amount of child nodes.
+ *
+ * @author David ‘Bombe’ Roden <bombe@freenetproject.org>
+ * @param <E>
+ * The type of the element to store
+ */
+public interface Node<E> extends Iterable<Node<E>> {
+
+ /**
+ * Returns the parent node of the node.
+ *
+ * @return The parent node
+ */
+ public Node<E> getParent();
+
+ /**
+ * Returns the element that is stored in the node.
+ *
+ * @return The node’s element
+ */
+ public E getElement();
+
+ /**
+ * Adds an element as a child to this node and returns the created node.
+ *
+ * @param child
+ * The child node’s element
+ * @return The created child node
+ */
+ public Node<E> addChild(E child);
+
+ /**
+ * Returns the number of children this node has.
+ *
+ * @return The number of children
+ */
+ public int size();
+
+ /**
+ * Returns the child at the given index.
+ *
+ * @param index
+ * The index of the child
+ * @return The child at the given index
+ */
+ public Node<E> getChild(int index);
+
+ /**
+ * Remove the given child node from this node. If the given node is not a
+ * child of this node, nothing happens.
+ *
+ * @param childNode
+ * The child node to remove
+ */
+ public void removeChild(Node<E> childNode);
+
+ /**
+ * Removes the child node that contains the given element. The element in
+ * the node is checked using {@link Object#equals(Object)}.
+ *
+ * @param child
+ * The child element to remove
+ */
+ public void removeChild(E child);
+
+ /**
+ * Removes the child at the given index.
+ *
+ * @param childIndex
+ * The index of the child to remove
+ */
+ public void removeChild(int childIndex);
+
+ /**
+ * {@inheritDoc}
+ */
+ public Iterator<Node<E>> iterator();
+
+}
\ No newline at end of file
--- /dev/null
+
+package net.pterodactylus.util.data;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * Implementation of the {@link Node} interface.
+ *
+ * @author David ‘Bombe’ Roden <bombe@freenetproject.org>
+ * @param <E>
+ * The type of the element to store
+ */
+class NodeImpl<E> implements Node<E> {
+
+ /** The parent node of this node. */
+ private final Node<E> parentNode;
+
+ /** The element contained in this node. */
+ private final E element;
+
+ /** The child nodes of this node. */
+ private final List<Node<E>> children = new ArrayList<Node<E>>();
+
+ /**
+ * Creates a new root node.
+ */
+ NodeImpl() {
+ this.parentNode = null;
+ this.element = null;
+ }
+
+ /**
+ * Creates a new node with the given parent and element.
+ *
+ * @param parentNode
+ * The parent of this node
+ * @param element
+ * The element of this node
+ */
+ NodeImpl(Node<E> parentNode, E element) {
+ if ((parentNode == null) || (element == null)) {
+ throw new NullPointerException("null is not allowed as parent or element");
+ }
+ this.parentNode = parentNode;
+ this.element = element;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public Node<E> getParent() {
+ return parentNode;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public E getElement() {
+ return element;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public Node<E> addChild(E child) {
+ Node<E> childNode = new NodeImpl<E>(this, child);
+ children.add(childNode);
+ return childNode;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public int size() {
+ return children.size();
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public Node<E> getChild(int childIndex) {
+ return children.get(childIndex);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public void removeChild(Node<E> childNode) {
+ children.remove(childNode);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public void removeChild(E child) {
+ for (Node<E> childNode: children) {
+ if (child.equals(childNode.getElement())) {
+ children.remove(childNode);
+ break;
+ }
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public void removeChild(int childIndex) {
+ children.remove(childIndex);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public Iterator<Node<E>> iterator() {
+ return children.iterator();
+ }
+
+}
\ No newline at end of file
--- /dev/null
+/*
+ * jSite2 - Tree.java -
+ * Copyright © 2008 David Roden
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+package net.pterodactylus.util.data;
+
+/**
+ * A tree structure in which every node can have an arbitrary amount of
+ * children.
+ *
+ * @author David ‘Bombe’ Roden <bombe@freenetproject.org>
+ * @param <E>
+ * The type of the element to store
+ */
+public class Tree<E> {
+
+ /** The root node of the tree. */
+ private final Node<E> rootNode = new NodeImpl<E>();
+
+ /**
+ * Returns the root node of the tree.
+ *
+ * @return The root node of the tree
+ */
+ public Node<E> getRootNode() {
+ return rootNode;
+ }
+
+}
projects / jSite2.git / commitdiff