001: /*--
002:
003: $Id: Content.java,v 1.1 2005/04/27 09:32:40 wittek Exp $
004:
005: Copyright (C) 2004 Jason Hunter & Brett McLaughlin.
006: All rights reserved.
007:
008: Redistribution and use in source and binary forms, with or without
009: modification, are permitted provided that the following conditions
010: are met:
011:
012: 1. Redistributions of source code must retain the above copyright
013: notice, this list of conditions, and the following disclaimer.
014:
015: 2. Redistributions in binary form must reproduce the above copyright
016: notice, this list of conditions, and the disclaimer that follows
017: these conditions in the documentation and/or other materials
018: provided with the distribution.
019:
020: 3. The name "JDOM" must not be used to endorse or promote products
021: derived from this software without prior written permission. For
022: written permission, please contact <request_AT_jdom_DOT_org>.
023:
024: 4. Products derived from this software may not be called "JDOM", nor
025: may "JDOM" appear in their name, without prior written permission
026: from the JDOM Project Management <request_AT_jdom_DOT_org>.
027:
028: In addition, we request (but do not require) that you include in the
029: end-user documentation provided with the redistribution and/or in the
030: software itself an acknowledgement equivalent to the following:
031: "This product includes software developed by the
032: JDOM Project (http://www.jdom.org/)."
033: Alternatively, the acknowledgment may be graphical using the logos
034: available at http://www.jdom.org/images/logos.
035:
036: THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
037: WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
038: OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
039: DISCLAIMED. IN NO EVENT SHALL THE JDOM AUTHORS OR THE PROJECT
040: CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
041: SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
042: LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
043: USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
044: ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
045: OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
046: OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
047: SUCH DAMAGE.
048:
049: This software consists of voluntary contributions made by many
050: individuals on behalf of the JDOM Project and was originally
051: created by Jason Hunter <jhunter_AT_jdom_DOT_org> and
052: Brett McLaughlin <brett_AT_jdom_DOT_org>. For more information
053: on the JDOM Project, please see <http://www.jdom.org/>.
054:
055: */
056:
057: package org.jdom;
058:
059: import java.io.*;
060:
061: /**
062: * Superclass for JDOM objects which can be legal child content
063: * of {@link org.jdom.Parent} nodes.
064: *
065: * @see org.jdom.Comment
066: * @see org.jdom.DocType
067: * @see org.jdom.Element
068: * @see org.jdom.EntityRef
069: * @see org.jdom.Parent
070: * @see org.jdom.ProcessingInstruction
071: * @see org.jdom.Text
072: *
073: * @author Bradley S. Huffman
074: * @author Jason Hunter
075: * @version $Revision: 1.1 $, $Date: 2005/04/27 09:32:40 $
076: */
077: public abstract class Content implements Cloneable, Serializable {
078:
079: protected Parent parent = null;
080:
081: protected Content() {
082: }
083:
084: /**
085: * Detaches this child from its parent or does nothing if the child
086: * has no parent.
087: *
088: * @return this child detached
089: */
090: public Content detach() {
091: if (parent != null) {
092: parent.removeContent(this );
093: }
094: return this ;
095: }
096:
097: /**
098: * Return this child's parent, or null if this child is currently
099: * not attached. The parent can be either an {@link Element}
100: * or a {@link Document}.
101: *
102: * @return this child's parent or null if none
103: */
104: public Parent getParent() {
105: return parent;
106: }
107:
108: /**
109: * A convenience method that returns any parent element for this element,
110: * or null if the element is unattached or is a root element. This was the
111: * original behavior of getParent() in JDOM Beta 9 which began returning
112: * Parent in Beta 10. This method provides a convenient upgrade path for
113: * JDOM Beta 10 and 1.0 users.
114: *
115: * @return the containing Element or null if unattached or a root element
116: */
117: public Element getParentElement() {
118: Parent parent = getParent();
119: return (Element) ((parent instanceof Element) ? parent : null);
120: }
121:
122: /**
123: * Sets the parent of this Content. The caller is responsible for removing
124: * any pre-existing parentage.
125: *
126: * @param parent new parent element
127: * @return the target element
128: */
129: protected Content setParent(Parent parent) {
130: this .parent = parent;
131: return this ;
132: }
133:
134: /**
135: * Return this child's owning document or null if the branch containing
136: * this child is currently not attached to a document.
137: *
138: * @return this child's owning document or null if none
139: */
140: public Document getDocument() {
141: if (parent == null)
142: return null;
143: return parent.getDocument();
144: }
145:
146: /**
147: * Returns the XPath 1.0 string value of this child.
148: *
149: * @return xpath string value of this child.
150: */
151: public abstract String getValue();
152:
153: /**
154: * Returns a deep, unattached copy of this child and its descendants
155: * detached from any parent or document.
156: *
157: * @return a detached deep copy of this child and descendants
158: */
159: public Object clone() {
160: try {
161: Content c = (Content) super .clone();
162: c.parent = null;
163: return c;
164: } catch (CloneNotSupportedException e) {
165: //Can not happen ....
166: //e.printStackTrace();
167: return null;
168: }
169: }
170:
171: /**
172: * This tests for equality of this Content object to the supplied object.
173: * Content items are considered equal only if they are referentially equal
174: * (i.e. the same object). User code may choose to compare objects
175: * based on their properties instead.
176: *
177: * @param ob <code>Object</code> to compare to.
178: * @return <code>boolean</code> - whether the <code>Content</code> is
179: * equal to the supplied <code>Object</code>.
180: */
181: public final boolean equals(Object ob) {
182: return (ob == this );
183: }
184:
185: /**
186: * This returns the hash code for this <code>Content</code> item.
187: *
188: * @return <code>int</code> - hash code.
189: */
190: public final int hashCode() {
191: return super.hashCode();
192: }
193: }
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