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/*******************************************************************************
 * Copyright (C) 2020, exense GmbH
 *  
 * This file is part of STEP
 *  
 * STEP is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *  
 * STEP is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *  
 * You should have received a copy of the GNU Affero General Public License
 * along with STEP.  If not, see .
 ******************************************************************************/
package step.commons.buffering;

import java.util.Iterator;

public class TreeIterator implements Iterator {

	final Iterator it;
	
	final TreeIteratorFactory factory; 

	Iterator childrenIt = null;

	public TreeIterator(Iterator it, TreeIteratorFactory factory) {
		super();
		this.it = it;
		this.factory = factory;
	}

	@Override
	public boolean hasNext() {
		return it.hasNext() || (childrenIt != null && childrenIt.hasNext());
	}

	@Override
	public T next() {
		if (childrenIt == null || !childrenIt.hasNext()) {
			T nextParent = it.next();
			childrenIt = new TreeIterator(factory.getChildrenIterator(nextParent), factory);
			return nextParent;
		} else {
			return childrenIt.next();
		}
	}

	@Override
	public void remove() {
		throw new RuntimeException("Remove method not supported!");
	}
	
}