/*****************************************************************
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
****************************************************************/
/* ====================================================================
*
* Copyright(c) 2003, Andriy Shapochka
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* 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. Neither the name of the ASHWOOD nor the
* names of its contributors may be used to endorse or
* promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS 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 THE COPYRIGHT OWNER OR 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.
*
* ====================================================================
*
* This software consists of voluntary contributions made by
* individuals on behalf of the ASHWOOD Project and was originally
* created by Andriy Shapochka.
*
*/
package org.apache.cayenne.ashwood.graph;
import java.util.NoSuchElementException;
import org.apache.commons.collections.Predicate;
/**
* @since 3.1
*/
public class FilterArcIterator<E, V> implements ArcIterator<E, V> {
private ArcIterator<E, V> iterator;
private Predicate acceptOrigin, acceptDestination;
private Predicate acceptArc;
private E nextOrigin, nextDst;
private V nextArc;
private boolean nextObjectSet = false;
public FilterArcIterator(ArcIterator<E, V> iterator, Predicate acceptOrigin,
Predicate acceptDestination, Predicate acceptArc) {
this.iterator = iterator;
this.acceptOrigin = acceptOrigin;
this.acceptDestination = acceptDestination;
this.acceptArc = acceptArc;
nextOrigin = iterator.getOrigin();
if (!acceptOrigin.evaluate(nextOrigin))
nextOrigin = null;
nextDst = iterator.getDestination();
if (!acceptDestination.evaluate(nextDst))
nextDst = null;
}
public E getOrigin() {
return nextOrigin;
}
public E getDestination() {
return nextDst;
}
public boolean hasNext() {
if (nextObjectSet) {
return true;
}
else {
return setNextObject();
}
}
public V next() {
if (!nextObjectSet) {
if (!setNextObject()) {
throw new NoSuchElementException();
}
}
nextObjectSet = false;
return nextArc;
}
public void remove() {
throw new UnsupportedOperationException();
}
private boolean setNextObject() {
while (iterator.hasNext()) {
V arc = iterator.next();
E origin = iterator.getOrigin();
E dst = iterator.getDestination();
if (acceptOrigin.evaluate(origin)
&& acceptArc.evaluate(arc)
&& acceptDestination.evaluate(dst)) {
nextArc = arc;
nextOrigin = origin;
nextDst = dst;
nextObjectSet = true;
return true;
}
}
return false;
}
}