org.apache.fop.layoutmgr.LMiter Maven / Gradle / Ivy
/*
* 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.
*/
/* $Id: LMiter.java 1610839 2014-07-15 20:25:58Z vhennebert $ */
package org.apache.fop.layoutmgr;
import java.util.List;
import java.util.ListIterator;
import java.util.NoSuchElementException;
/** An iterator for layout managers. */
public class LMiter implements ListIterator {
/** list of layout managers */
protected List listLMs;
/** current position in iteration */
protected int curPos;
/** The LayoutManager to which this LMiter is attached **/
private LayoutManager lp;
/**
* Construct a layout manager iterator.
* @param lp the associated layout manager (parent)
*/
public LMiter(LayoutManager lp) {
this.lp = lp;
listLMs = lp.getChildLMs();
}
/** {@inheritDoc} */
public boolean hasNext() {
return (curPos < listLMs.size()) || lp.createNextChildLMs(curPos);
}
/** {@inheritDoc} */
public boolean hasPrevious() {
return (curPos > 0);
}
/** {@inheritDoc} */
public LayoutManager previous() throws NoSuchElementException {
if (curPos > 0) {
return listLMs.get(--curPos);
} else {
throw new NoSuchElementException();
}
}
/** {@inheritDoc} */
public LayoutManager next() throws NoSuchElementException {
if (curPos < listLMs.size()) {
return listLMs.get(curPos++);
} else {
throw new NoSuchElementException();
}
}
/** {@inheritDoc} */
public void remove() throws NoSuchElementException {
if (curPos > 0) {
listLMs.remove(--curPos);
// Note: doesn't actually remove it from the base!
} else {
throw new NoSuchElementException();
}
}
/** {@inheritDoc} */
public void add(LayoutManager lm) throws UnsupportedOperationException {
throw new UnsupportedOperationException("LMiter doesn't support add");
}
/** {@inheritDoc} */
public void set(LayoutManager lm) throws UnsupportedOperationException {
throw new UnsupportedOperationException("LMiter doesn't support set");
}
/** {@inheritDoc} */
public int nextIndex() {
return curPos;
}
/** {@inheritDoc} */
public int previousIndex() {
return curPos - 1;
}
}