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;
  
  
  /**
   * <p>Class that creates a new data source which adds a leading column
   * containing the row number.</p>
   *
   * <p>Example which creates a two column data source from a one column
   * histogram:</p>
   * <pre>
   * DataSource hist = new Histogram1D(data, Orientation.HORIZONTAL, 10);
   * DataSource hist2d = new EnumeratedData(hist);
   * </pre>
   *
   * @see DataSource
   */
  public class EnumeratedData extends AbstractDataSource
  		implements DataListener {
  	/** Version id for serialization. */
  	private static final long serialVersionUID = -4952487410608980063L;
  
  	/** Data source which will be used as base for enumeration. */
  	private final DataSource original;
  	/** Value to start counting from. */
  	private final double offset;
  	/** Width of enumeration steps. */
  	private final double steps;
  
  	/**
  	 * Initializes a new data source based on an original data source which
  	 * will contain an additional column which enumerates all rows. The
  	 * enumeration will start at a specified offset and will have a specified
  	 * step size.
  	 * @param original Original data source.
  	 * @param offset Offset of enumeration
  	 * @param steps Scaling of enumeration
  	 */
  	@SuppressWarnings("unchecked")
  	public EnumeratedData(DataSource original, double offset, double steps) {
  		this.original = original;
  		this.offset = offset;
  		this.steps = steps;
  
  		Class<? extends Comparable<?>>[] typesOrig = original.getColumnTypes();
  		Class<? extends Comparable<?>>[] types = new Class[typesOrig.length + 1];
  		System.arraycopy(typesOrig, 0, types, 1, typesOrig.length);
  		types[0] = Double.class;
  		setColumnTypes(types);
  
  		original.addDataListener(this);
  	}
  
  	/**
  	 * Initializes a new data source based on an original data source which
  	 * will contain an additional column which enumerates all rows.
  	 * @param original Original data source.
  	 */
  	public EnumeratedData(DataSource original) {
  		this(original, 0, 1);
  	}
  
  	/**
  	 * 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) {
  		if (col < 1) {
  			return row*steps + offset;
  		}
  		return original.get(col - 1, row);
  	}
  
  	/**
  	 * Returns the number of rows of the data source.
  	 * @return number of rows in the data source.
  	 */
  	public int getRowCount() {
  		return original.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(takeEvents(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(takeEvents(events));
  	}
  
  	/**
  	 * 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 removed.
  	 */
  	public void dataRemoved(DataSource source, DataChangeEvent... events) {
  		notifyDataRemoved(takeEvents(events));
  	}
  
  	/**
  	 * Changes the source and the columns of the specified event objects to
  	 * make them look as if they originated from this data source.
  	 * @param events Original events.
  	 * @return Changed events.
  	 */
  	@SuppressWarnings({ "rawtypes", "unchecked" })
  	private DataChangeEvent[] takeEvents(DataChangeEvent[] events) {
  		if (events == null || events.length == 0) {
  			return new DataChangeEvent[] {
  				new DataChangeEvent(this, 0, 0, null, null)
  			};
  		}
  		DataChangeEvent[] eventsTx = new DataChangeEvent[events.length + 1];
  		for (int i = 0; i < eventsTx.length; i++) {
  			DataChangeEvent event;
  			int col, row;
  			if (i == 0) {
  				// Insert an event for the generated column
  				event = events[0];
  				col = 0;
  				row = event.getRow();
  			} else {
  				// Process the columns of the original source
  				event = events[i - 1];
  				col = event.getCol() + 1;
  				row = event.getRow();
  			}
  			Comparable valOld = event.getOld();
  			Comparable valNew = event.getNew();
  			eventsTx[i] = new DataChangeEvent(
  				this, col, row, valOld, valNew);
  		}
  		return eventsTx;
  	}
  }
  