package com.planet_ink.coffee_mud.core.collections;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Vector;
/*
Copyright 2011-2019 Bo Zimmerman
Licensed 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.
*/
public class MultiListEnumeration<K> implements Enumeration<K>
{
private final LinkedList<Iterable<K>> lists=new LinkedList<Iterable<K>>();
private volatile Iterator<Iterable<K>> listIter = null;
private volatile Iterator<K> iter = null;
public MultiListEnumeration(final Iterable<K>[] esets)
{
if((esets!=null)&&(esets.length>0))
lists.addAll(Arrays.asList(esets));
setup(false);
}
public MultiListEnumeration(final List<List<K>> esetss, final boolean diffMethodSignature)
{
if((esetss!=null)&&(esetss.size()>0))
lists.addAll(esetss);
setup(false);
}
public MultiListEnumeration(final Iterable<K> eset)
{
lists.add(eset);
setup(false);
}
private void setup(final boolean startOver)
{
if(startOver||(listIter==null))
listIter=lists.iterator();
if(startOver||(iter == null))
{
if(listIter.hasNext())
iter=listIter.next().iterator();
}
}
public void addEnumeration(final List<K> set)
{
if(set != null)
lists.add(set);
setup(true);
}
@Override
public boolean hasMoreElements()
{
boolean hasMore = (iter != null) && iter.hasNext();
while(!hasMore)
{
if((listIter == null)||(!listIter.hasNext()))
{
iter=null;
listIter = null;
return false;
}
iter = listIter.next().iterator();
hasMore = (iter != null) && iter.hasNext();
}
return hasMore;
}
@Override
public K nextElement()
{
if(!hasMoreElements())
throw new NoSuchElementException();
return iter.next();
}
}
