/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2014 by RapidMiner and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapidminer.com
 *
 *  This program 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.
 *
 *  This program 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 this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.gui.new_plotter.utility;

import java.lang.ref.WeakReference;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import com.rapidminer.gui.new_plotter.listener.ValueRangeListener;
import com.rapidminer.gui.new_plotter.listener.events.ValueRangeChangeEvent;

/**
 * Value range that is a abstract superclass for most value ranges. 
 * Implements applyRange and applyRangeOnDataTableRows. 
 * 
 * @author Marius Helf, Nils Woehler
 *
 */
public abstract class AbstractValueRange implements ValueRange, Cloneable {

	private transient List<WeakReference<ValueRangeListener>> listeners = new LinkedList<WeakReference<ValueRangeListener>>();
	
	@Override
	public abstract ValueRange clone();

	@Override
	public abstract boolean equals(Object obj);
	
	@Override
	public void addValueRangeListener(ValueRangeListener l) {
		listeners.add(new WeakReference<ValueRangeListener>(l));
	}
	
	@Override
	public void removeValueRangeListener(ValueRangeListener l) {
		Iterator<WeakReference<ValueRangeListener>> it = listeners.iterator();
		while (it.hasNext()) {
			ValueRangeListener listener = it.next().get();
			if (listener == null || listener == l) {
				it.remove();
			}
		}
	}

	protected void fireValueRangeChanged(ValueRangeChangeEvent e) {
		Iterator<WeakReference<ValueRangeListener>> it = listeners.iterator();
		while (it.hasNext()) {
			ValueRangeListener listener = it.next().get();
			if (listener == null) {
				it.remove();
			} else {
				listener.valueRangeChanged(e);
			}
		}
	}
}