/******************************************************************************* * Copyright (c) 2005 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: *     IBM Corporation - initial API and implementation ******************************************************************************/package org.eclipse.jface.viewers;import org.eclipse.jface.util.Util;/** * A simple data structure that is useful for implemented tree models. This can * be returned by * {@link org.eclipse.jface.viewers.IStructuredContentProvider#getElements(Object)}. * It allows simple delegation of methods from * {@link org.eclipse.jface.viewers.ITreeContentProvider} such as * {@link org.eclipse.jface.viewers.ITreeContentProvider#getChildren(Object)}, * {@link org.eclipse.jface.viewers.ITreeContentProvider#getParent(Object)} and * {@link org.eclipse.jface.viewers.ITreeContentProvider#hasChildren(Object)} *  * @since 3.2 */public class TreeNode {	/**	 * The array of child tree nodes for this tree node. If there are no	 * children, then this value may either by an empty array or	 * <code>null</code>. There should be no <code>null</code> children in	 * the array.	 */	private TreeNode[] children;	/**	 * The parent tree node for this tree node. This value may be	 * <code>null</code> if there is no parent.	 */	private TreeNode parent;	/**	 * The value contained in this node. This value may be anything.	 */	protected Object value;	/**	 * Constructs a new instance of <code>TreeNode</code>.	 * 	 * @param value	 *            The value held by this node; may be anything.	 */	public TreeNode(final Object value) {		this.value = value;	}		public boolean equals(final Object object) {		if (object instanceof TreeNode) {			return Util.equals(this.value, ((TreeNode) object).value);		}		return false;	}	/**	 * Returns the child nodes. Empty arrays are converted to <code>null</code>	 * before being returned.	 * 	 * @return The child nodes; may be <code>null</code>, but never empty.	 *         There should be no <code>null</code> children in the array.	 */	public TreeNode[] getChildren() {		if (children != null && children.length == 0) {			return null;		}		return children;	}	/**	 * Returns the parent node.	 * 	 * @return The parent node; may be <code>null</code> if there are no	 *         parent nodes.	 */	public TreeNode getParent() {		return parent;	}	/**	 * Returns the value held by this node.	 * 	 * @return The value; may be anything.	 */	public Object getValue() {		return value;	}	/**	 * Returns whether the tree has any children.	 * 	 * @return <code>true</code> if its array of children is not	 *         <code>null</code> and is non-empty; <code>false</code>	 *         otherwise.	 */	public boolean hasChildren() {		return children != null && children.length > 0;	}		public int hashCode() {		return Util.hashCode(value);	}	/**	 * Sets the children for this node.	 * 	 * @param children	 *            The child nodes; may be <code>null</code> or empty. There	 *            should be no <code>null</code> children in the array.	 */	public void setChildren(final TreeNode[] children) {		this.children = children;	}	/**	 * Sets the parent for this node.	 * 	 * @param parent	 *            The parent node; may be <code>null</code>.	 */	public void setParent(final TreeNode parent) {		this.parent = parent;	}}