content: // ===============================================================================
  // Authors: AFRL/RQQD
  // Organization: Air Force Research Laboratory, Aerospace Systems Directorate, Power and Control Division
  // 
  // Copyright (c) 2017 Government of the United State of America, as represented by
  // the Secretary of the Air Force.  No copyright is claimed in the United States under
  // Title 17, U.S. Code.  All Other Rights Reserved.
  // ===============================================================================
  
  /*
   * GRAL: GRAphing Library for Java(R)
   *
   * (C) Copyright 2009-2013 Erich Seifert <dev[at]erichseifert.de>,
   * Michael Seifert <mseifert[at]error-reports.org>
   *
   * This file is part of GRAL.
   *
   * GRAL is free software: you can redistribute it and/or modify
   * it under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or
   * (at your option) any later version.
   *
   * GRAL 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 Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public License
   * along with GRAL.  If not, see <http://www.gnu.org/licenses/>.
   */
  package de.erichseifert.gral.data;
  
  import java.io.IOException;
  import java.io.ObjectInputStream;
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Class that represents a view on several columns of a {@code DataSource}.
   * @see DataSource
   */
  public class DataSeries extends AbstractDataSource implements DataListener {
  	/** Version id for serialization. */
  	private static final long serialVersionUID = 5568085894125740972L;
  
  	/** Data source that provides the columns for this data series. */
  	private final DataSource data;
  	/** Columns that should be mapped to the series. */
  	private final List<Integer> cols;
  	/** Name of the data series. */
  	private String name;
  
  	/**
  	 * Constructor without name. The first column will be column
  	 * {@code 0}, the second column {@code 1} and so on,
  	 * whereas the value of the specified columns is the column number
  	 * in the data source.
  	 * @param data Data source
  	 * @param cols Column numbers
  	 */
  	public DataSeries(DataSource data, int... cols) {
  		this(null, data, cols);
  	}
  
  	/**
  	 * Constructor that initializes a named data series. The first column will
  	 * be column {@code 0}, the second column {@code 1} and so on,
  	 * whereas the value of the specified columns is the column number in the
  	 * data source.
  	 * @param name Descriptive name
  	 * @param data Data source
  	 * @param cols Column numbers
  	 */
  	@SuppressWarnings("unchecked")
  	public DataSeries(String name, DataSource data, int... cols) {
  		this.data = data;
  		this.cols = new ArrayList<Integer>();
  		this.name = name;
  		this.data.addDataListener(this);
  
  		Class<? extends Comparable<?>>[] typesOrig = data.getColumnTypes();
  		Class<? extends Comparable<?>>[] types = null;
  
  		if (cols.length > 0) {
  			types = new Class[cols.length];
  			int t = 0;
  			for (int colIndex : cols) {
  				this.cols.add(colIndex);
  				types[t++] = typesOrig[colIndex];
  			}
  		} else {
  			for (int colIndex = 0; colIndex < data.getColumnCount(); colIndex++) {
  				this.cols.add(colIndex);
  			}
  			types = typesOrig;
  		}
  
  		setColumnTypes(types);
  	}
  
  	/**
  	 * Returns the name of this series.
  	 * @return a name string
  	 */
  	public String getName() {
  		return name;
  	}
  
  	/**
  	 * Sets the name of this series.
  	 * @param name name to be set
  	 */
  	public void setName(String name) {
  		this.name = name;
  	}
  
  	/**
  	 * Returns the row with the specified index.
  	 * @param col index of the column to return
  	 * @param row index of the row to return
  	 * @return the specified value of the data cell
  	 */
  	public Comparable<?> get(int col, int row) {
  		try {
  			int dataCol = cols.get(col);
  			return data.get(dataCol, row);
  		} catch (IndexOutOfBoundsException e) {
  			return null;
  		}
  	}
  
  	@Override
  	public int getColumnCount() {
  		return cols.size();
  	}
  
  	/**
  	 * Returns the number of rows of the data source.
  	 * @return number of rows in the data source.
  	 */
  	public int getRowCount() {
  		return data.getRowCount();
  	}
  
  	/**
  	 * Method that is invoked when data has been added.
  	 * This method is invoked by objects that provide support for
  	 * {@code DataListener}s and should not be called manually.
  	 * @param source Data source that has been changed.
  	 * @param events Optional event object describing the data values that
  	 *        have been added.
  	 */
  	public void dataAdded(DataSource source, DataChangeEvent... events) {
  		notifyDataAdded(events);
  	}
  
  	/**
  	 * Method that is invoked when data has been updated.
  	 * This method is invoked by objects that provide support for
  	 * {@code DataListener}s and should not be called manually.
  	 * @param source Data source that has been changed.
  	 * @param events Optional event object describing the data values that
  	 *        have been updated.
  	 */
  	public void dataUpdated(DataSource source, DataChangeEvent... events) {
  		notifyDataUpdated(events);
  	}
  
  	/**
  	 * Method that is invoked when data has been removed.
  	 * This method is invoked by objects that provide support for
  	 * {@code DataListener}s and should not be called manually.
  	 * @param source Data source that has been changed.
  	 * @param events Optional event object describing the data values that
  	 *        have been removed.
  	 */
  	public void dataRemoved(DataSource source, DataChangeEvent... events) {
  		notifyDataRemoved(events);
  	}
  
  	@Override
  	public String toString() {
  		return getName();
  	}
  
  	/**
  	 * Custom deserialization method.
  	 * @param in Input stream.
  	 * @throws ClassNotFoundException if a serialized class doesn't exist anymore.
  	 * @throws IOException if there is an error while reading data from the
  	 *         input stream.
  	 */
  	private void readObject(ObjectInputStream in)
  			throws ClassNotFoundException, IOException {
  		// Normal deserialization
  		in.defaultReadObject();
  
  		// Restore listeners
  		data.addDataListener(this);
  	}
  }
  