001: /*
002: * Copyright (c) 1998-2008 Caucho Technology -- all rights reserved
003: *
004: * This file is part of Resin(R) Open Source
005: *
006: * Each copy or derived work must preserve the copyright notice and this
007: * notice unmodified.
008: *
009: * Resin Open Source is free software; you can redistribute it and/or modify
010: * it under the terms of the GNU General Public License as published by
011: * the Free Software Foundation; either version 2 of the License, or
012: * (at your option) any later version.
013: *
014: * Resin Open Source is distributed in the hope that it will be useful,
015: * but WITHOUT ANY WARRANTY; without even the implied warranty of
016: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
017: * of NON-INFRINGEMENT. See the GNU General Public License for more
018: * details.
019: *
020: * You should have received a copy of the GNU General Public License
021: * along with Resin Open Source; if not, write to the
022: * Free SoftwareFoundation, Inc.
023: * 59 Temple Place, Suite 330
024: * Boston, MA 02111-1307 USA
025: *
026: * @author Scott Ferguson
027: */
028:
029: package com.caucho.xpath.pattern;
030:
031: import com.caucho.xpath.ExprEnvironment;
032:
033: import org.w3c.dom.Document;
034: import org.w3c.dom.Node;
035:
036: /**
037: * Represents a match with the document root.
038: */
039: public class FromRoot extends Axis {
040: public FromRoot() {
041: super (null);
042: }
043:
044: /**
045: * Matches the owner document.
046: *
047: * @param node the current node
048: * @param env the variable environment
049: *
050: * @return true if the node is the owner document.
051: */
052: public boolean match(Node node, ExprEnvironment env) {
053: return (node instanceof Document);
054: }
055:
056: /**
057: * Returns the first node in the selection order.
058: *
059: * @param node the current node
060: *
061: * @return the first node
062: */
063: public Node firstNode(Node node, ExprEnvironment env) {
064: Node doc = node.getOwnerDocument();
065:
066: if (doc != null)
067: return doc;
068: else
069: return node;
070: }
071:
072: /**
073: * Returns the next node in the selection order.
074: *
075: * @param node the current node
076: * @param lastNode the last node
077: *
078: * @return the next node
079: */
080: public Node nextNode(Node node, Node lastNode) {
081: return null;
082: }
083:
084: /**
085: * The root is strictly ascending.
086: */
087: public boolean isStrictlyAscending() {
088: return true;
089: }
090:
091: /**
092: * Returns true if the pattern selects a single node
093: */
094: boolean isSingleSelect() {
095: return true;
096: }
097:
098: /**
099: * Returns true if the two patterns are equal.
100: */
101: public boolean equals(Object b) {
102: return b instanceof FromRoot;
103: }
104:
105: public String toString() {
106: return "/";
107: }
108: }
|