/*
* 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.
*/
package org.apache.wicket.request.handler.render;
import java.util.Iterator;
import java.util.NoSuchElementException;
public class VariationIterator<T> implements Iterator<T>
{
private final VariationIterator<?> prev;
private final Variation<T> variation;
private int idx = -1;
public VariationIterator(Variation<T> variation) {
this(null, variation);
}
public VariationIterator(VariationIterator<?> prev, Variation<T> variation) {
this.prev = prev;
this.variation = variation;
}
public static <T> VariationIterator<T> of(Variation<T> variation) {
return new VariationIterator<>(variation);
}
public static <T> VariationIterator<T> of(VariationIterator<?> prev, Variation<T> variation)
{
return new VariationIterator<>(prev,variation);
}
@Override
public T next()
{
if (thisHasNextVariation())
{
idx++;
}
else
{
if (prevHasNextVariation())
{
idx = 0;
}
else
{
throw new NoSuchElementException("no variation left, but next called");
}
}
if (idx == 0 && prev != null)
{
prev.next();
}
return current();
}
public T current()
{
return variation.values().get(idx);
}
@Override
public boolean hasNext()
{
return thisHasNextVariation() || prevHasNextVariation();
}
private boolean prevHasNextVariation()
{
return (prev != null && prev.hasNext());
}
private boolean thisHasNextVariation()
{
return idx < variation.values().size() - 1;
}
@Override
public void remove()
{
}
}