/*
* Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
*
* This software is open source.
* See the bottom of this file for the licence.
*/
package org.dom4j.tree;
import java.util.
Iterator;
import java.util.
NoSuchElementException;
/**
* <p>
* <code>FilterIterator</code> is an abstract base class which is useful for
* implementors of {@link Iterator}which filter an existing iterator.
* </p>
*
* @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
* @version $Revision: 1.10 $
*
* @deprecated THIS CLASS WILL BE REMOVED IN dom4j-1.6 !!
*/
public abstract class
FilterIterator implements
Iterator {
protected
Iterator proxy;
private
Object next;
private boolean
first = true;
public
FilterIterator(
Iterator proxy) {
this.
proxy =
proxy;
}
public boolean
hasNext() {
if (
first) {
next =
findNext();
first = false;
}
return
next != null;
}
public
Object next() throws
NoSuchElementException {
if (!
hasNext()) {
throw new
NoSuchElementException();
}
Object answer = this.
next;
this.
next =
findNext();
return
answer;
}
/**
* Always throws UnsupportedOperationException as this class does look-ahead
* with its internal iterator.
*
* @throws UnsupportedOperationException
* always
*/
public void
remove() {
throw new
UnsupportedOperationException();
}
/**
* Filter method to perform some matching on the given element.
*
* @param element
* DOCUMENT ME!
*
* @return true if the given element matches the filter and should be appear
* in the iteration
*/
protected abstract boolean
matches(
Object element);
protected
Object findNext() {
if (
proxy != null) {
while (
proxy.
hasNext()) {
Object nextObject =
proxy.
next();
if ((
nextObject != null) &&
matches(
nextObject)) {
return
nextObject;
}
}
proxy = null;
}
return null;
}
}
/*
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain copyright statements and
* notices. Redistributions must also contain a copy of this document.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The name "DOM4J" must not be used to endorse or promote products derived
* from this Software without prior written permission of MetaStuff, Ltd. For
* written permission, please contact dom4j-info@metastuff.com.
*
* 4. Products derived from this Software may not be called "DOM4J" nor may
* "DOM4J" appear in their names without prior written permission of MetaStuff,
* Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
*
* 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
*
* THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
*/