| /******************************************************************************* |
| * Copyright (c) 2006 Sybase, Inc. 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: |
| * Sybase, Inc. - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jst.pagedesigner.utils; |
| |
| import java.util.Comparator; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.eclipse.core.runtime.Assert; |
| import org.w3c.dom.Node; |
| |
| /** |
| * To sort the location of tags, this comparator is used to compare tags' order. |
| * |
| * @author mengbo |
| */ |
| public class NodeLocationComparator implements Comparator { |
| private final static Map orders = new HashMap(); |
| |
| private final static Integer DEFAULT_ORDER = Integer.valueOf(Integer.MAX_VALUE); |
| |
| private static NodeLocationComparator _instance = new NodeLocationComparator(); |
| static { |
| orders.put("taglib", Integer.valueOf(0)); |
| orders.put("directive.taglib", Integer.valueOf(0)); |
| orders.put("head", Integer.valueOf(1)); |
| } |
| |
| private NodeLocationComparator() { |
| // no external instantiation |
| } |
| |
| /** |
| * @return the singleton |
| */ |
| public static NodeLocationComparator getInstance() { |
| return _instance; |
| } |
| |
| /** |
| * The object to be compared could be Node or tag name. |
| * |
| * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object) |
| */ |
| public int compare(Object o1, Object o2) { |
| Assert.isTrue((o1 instanceof Node || o1 instanceof String) |
| && (o2 instanceof Node || o2 instanceof String)); |
| Integer i1 = getOrder(o1); |
| Integer i2 = getOrder(o2); |
| return i1.compareTo(i2); |
| } |
| |
| private Integer getOrder(Object n) { |
| String name = null; |
| if (n instanceof Node) { |
| name = ((Node) n).getLocalName(); |
| } else { |
| name = (String) n; |
| } |
| if (name != null) { |
| Object order = orders.get(name); |
| if (order != null) { |
| return (Integer) order; |
| } |
| } |
| return DEFAULT_ORDER; |
| } |
| } |