package com.planet_ink.coffee_mud.core.collections;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
import java.util.NoSuchElementException;
import java.util.Vector;
/*
Copyright 2016-2019 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 MultiListListIterator<K> implements ListIterator<K>
{
private final List<ListIterator<K>> iters=new ArrayList<ListIterator<K>>();
private volatile ListIterator<K> iter=null;
private volatile int listIndex = 0;
private volatile int itemIndex = 0;
public MultiListListIterator(final ListIterator<K>[] esets)
{
if((esets==null)||(esets.length==0))
return;
for(final ListIterator<K> I : esets)
iters.add(I);
}
public MultiListListIterator(final Collection<ListIterator<K>> esets)
{
if((esets==null)||(esets.size()==0))
return;
iters.addAll(esets);
for(final ListIterator<K> I : esets)
iters.add(I);
}
public MultiListListIterator(final List<K>[] esets)
{
if((esets==null)||(esets.length==0))
return;
for(final List<K> I : esets)
iters.add(I.listIterator());
}
public MultiListListIterator(final List<? extends List<K>> esets)
{
if(esets==null)
return;
for(final List<K> I : esets)
iters.add(I.listIterator());
}
public MultiListListIterator()
{
}
public void add(final ListIterator<K> eset)
{
iters.add(eset);
}
@Override
public boolean hasNext()
{
boolean hasNext = (iter != null) && iter.hasNext();
while(!hasNext)
{
if((iters.size()==0)
||(listIndex<0)
||(listIndex>=iters.size()))
{
iter=null;
return false;
}
iter=iters.get(listIndex++);
hasNext = (iter != null) && iter.hasNext();
}
return hasNext;
}
@Override
public K next()
{
if(!hasNext())
throw new NoSuchElementException();
itemIndex++;
return iter.next();
}
@Override
public void remove()
{
if(iter != null)
iter.remove();
}
@Override
public boolean hasPrevious()
{
boolean hasPrevious = (iter != null) && iter.hasPrevious();
while(!hasPrevious)
{
if((iters.size()==0)
||(listIndex<0)
||(listIndex>=iters.size()))
{
iter=null;
return false;
}
iter=iters.get(listIndex--);
hasPrevious = (iter != null) && iter.hasPrevious();
}
return hasPrevious;
}
@Override
public K previous()
{
if(!hasPrevious())
throw new NoSuchElementException();
itemIndex--;
return iter.previous();
}
@Override
public int nextIndex()
{
return itemIndex;
}
@Override
public int previousIndex()
{
return itemIndex-1;
}
@Override
public void set(final K e)
{
if(hasNext())
iter.set(e);
else
if(hasPrevious())
iter.set(e);
}
@Override
public void add(final K e)
{
if(hasNext())
iter.add(e);
else
if(hasPrevious())
iter.add(e);
}
}
