/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library 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 2.1 of the License, or 
 * (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * --------------
 * TickUnits.java
 * --------------
 * (C) Copyright 2001-2005, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: TickUnits.java,v 1.4.2.2 2005/10/25 20:37:34 mungady Exp $
 *
 * Changes
 * -------
 * 23-Nov-2001 : Version 1 (DG);
 * 18-Feb-2002 : Fixed bug in getNearestTickUnit (thanks to Mario Inchiosa for 
 *               reporting this, SourceForge bug id 518073) (DG);
 * 25-Feb-2002 : Moved createStandardTickUnits() method from NumberAxis, and 
 *               added createIntegerTickUnits() method (DG);
 * 01-May-2002 : Updated for changes to the TickUnit class (DG);
 * 18-Sep-2002 : Added standardTickUnit methods which take a Locale 
 *               instance (AS);
 * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
 * 08-Nov-2002 : Moved to new package com.jrefinery.chart.axis (DG);
 * 26-Mar-2003 : Implemented Serializable (DG);
 * 13-Aug-2003 : Implemented Cloneable (DG);
 * 23-Sep-2003 : Implemented TickUnitSource interface (DG);
 * 03-Dec-2003 : Adding null values now throws exceptions (TM);
 * 11-Jan-2005 : Removed deprecated methods in preparation for 1.0.0 
 *               release (DG);
 * 
 */

package org.jfree.chart.axis;

import java.io.Serializable;
import java.text.NumberFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * A collection of tick units, used by the {@link DateAxis} and 
 * {@link NumberAxis} classes.
 */
public class TickUnits implements TickUnitSource, Cloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = 1134174035901467545L;
    
    /** Storage for the tick units. */
    private List tickUnits;

    /**
     * Constructs a new collection of tick units.
     */
    public TickUnits() {
        this.tickUnits = new ArrayList();
    }

    /**
     * Adds a tick unit to the collection.
     * <P>
     * The tick units are maintained in ascending order.
     *
     * @param unit  the tick unit to add.
     */
    public void add(TickUnit unit) {

        if (unit == null) {
            throw new NullPointerException("Null 'unit' argument.");
        }
        this.tickUnits.add(unit);
        Collections.sort(this.tickUnits);

    }

    /**
     * Returns the number of tick units in this collection.
     * <P>
     * This method is required for the XML writer.
     *
     * @return The number of units in this collection.
     */
    public int size() {
        return this.tickUnits.size();
    }

    /**
     * Returns the tickunit on the given position.
     * <P>
     * This method is required for the XML writer.
     *
     * @param pos the position in the list.
     * 
     * @return The tickunit.
     */
    public TickUnit get(int pos) {
        return (TickUnit) this.tickUnits.get(pos);
    }

    /**
     * Returns a tick unit that is larger than the supplied unit.
     *
     * @param unit   the unit.
     *
     * @return A tick unit that is larger than the supplied unit.
     */
    public TickUnit getLargerTickUnit(TickUnit unit) {

        int index = Collections.binarySearch(this.tickUnits, unit);
        if (index >= 0) {
            index = index + 1;
        }
        else {
            index = -index;
        }

        return (TickUnit) this.tickUnits.get(
            Math.min(index, this.tickUnits.size() - 1)
        );

    }

    /**
     * Returns the tick unit in the collection that is greater than or equal
     * to (in size) the specified unit.
     *
     * @param unit  the unit.
     *
     * @return A unit from the collection.
     */
    public TickUnit getCeilingTickUnit(TickUnit unit) {

        int index = Collections.binarySearch(this.tickUnits, unit);
        if (index >= 0) {
            return (TickUnit) this.tickUnits.get(index);
        }
        else {
            index = -(index + 1);
            return (TickUnit) this.tickUnits.get(
                Math.min(index, this.tickUnits.size() - 1)
            );
        }

    }

    /**
     * Returns the tick unit in the collection that is greater than or equal
     * to the specified size.
     *
     * @param size  the size.
     *
     * @return A unit from the collection.
     */
    public TickUnit getCeilingTickUnit(double size) {
        return getCeilingTickUnit(new NumberTickUnit(size, 
                NumberFormat.getInstance()));
    }

    /**
     * Returns a clone of the collection.
     *
     * @return A clone.
     *
     * @throws CloneNotSupportedException if an item in the collection does not 
     *         support cloning.
     */
    public Object clone() throws CloneNotSupportedException {
        TickUnits clone = (TickUnits) super.clone();
        clone.tickUnits = new java.util.ArrayList(this.tickUnits);
        return clone;
    }

    /**
     * Tests an object for equality with this instance.
     *
     * @param object  the object to test.
     *
     * @return A boolean.
     */
    public boolean equals(Object object) {
        if (object == null) {
            return false;
        }
        if (object == this) {
            return true;
        }
        if (object instanceof TickUnits) {
            TickUnits tu = (TickUnits) object;
            return tu.tickUnits.equals(this.tickUnits);
        }
        return false;
    }

}
