/* ===========================================================

 * JFreeChart : a free chart library for the Java(tm) platform

 * ===========================================================

 *

 * (C) Copyright 2000-2004, 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., 59 Temple Place, Suite 330,

 * Boston, MA 02111-1307, USA.

 *

 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 

 * in the United States and other countries.]

 *

 * ----------------------

 * DefaultPieDataset.java

 * ----------------------

 * (C) Copyright 2001-2004, by Object Refinery Limited.

 *

 * Original Author:  David Gilbert (for Object Refinery Limited);

 * Contributor(s):   Sam (oldman);

 *

 * $Id: DefaultPieDataset.java,v 1.1 2004/08/31 15:27:03 mungady Exp $

 *

 * Changes

 * -------

 * 17-Nov-2001 : Version 1 (DG);

 * 22-Jan-2002 : Removed legend methods from dataset implementations (DG);

 * 07-Apr-2002 : Modified implementation to guarantee data sequence to remain in the order

 *               categories are added (oldman);

 * 23-Oct-2002 : Added getCategory(int) method and getItemCount() method, in line with changes

 *               to the PieDataset interface (DG);

 * 04-Feb-2003 : Changed underlying data storage to DefaultKeyedValues (DG);

 * 04-Mar-2003 : Inserted DefaultKeyedValuesDataset class into hierarchy (DG);

 * 24-Apr-2003 : Switched places with DefaultKeyedValuesDataset (DG);

 * 18-Aug-2003 : Implemented Cloneable (DG);

 * 

 */



package org.jfree.data.general;



import java.io.Serializable;

import java.util.Collections;

import java.util.List;



import org.jfree.data.DefaultKeyedValues;

import org.jfree.data.KeyedValues;



/**

 * A default implementation of the {@link PieDataset} interface.

 *

 */

public class DefaultPieDataset extends AbstractDataset

                               implements PieDataset, Cloneable, Serializable {



    /** Storage for the data. */

    private DefaultKeyedValues data;



    /**

     * Constructs a new dataset, initially empty.

     */

    public DefaultPieDataset() {



        this.data = new DefaultKeyedValues();



    }



    /**

     * Creates a new dataset that uses the data from a {@link KeyedValues} instance.

     *

     * @param data  the data.

     */

    public DefaultPieDataset(final KeyedValues data) {



        this.data = new DefaultKeyedValues();

        for (int i = 0; i < data.getItemCount(); i++) {

            this.data.addValue(data.getKey(i), data.getValue(i));

        }

    }



    /**

     * Returns the number of items in the dataset.

     *

     * @return the item count.

     */

    public int getItemCount() {

        return this.data.getItemCount();

    }



    /**

     * Returns the categories in the dataset.  The returned list is unmodifiable.

     *

     * @return the categories in the dataset.

     */

    public List getKeys() {

        return Collections.unmodifiableList(this.data.getKeys());

    }



    /**

     * Returns the key for an item.

     *

     * @param item  the item index (zero-based).

     *

     * @return the category.

     */

    public Comparable getKey(final int item) {



        Comparable result = null;

        if (getItemCount() > item) {

            result = this.data.getKey(item);

        }

        return result;



    }



    /**

     * Returns the index for a key.

     *

     * @param key  the key.

     *

     * @return the key index.

     */

    public int getIndex(final Comparable key) {



        return this.data.getIndex(key);



    }



    /**

     * Returns a value.

     *

     * @param item  the value index.

     *

     * @return the value (possibly <code>null</code>).

     */

    public Number getValue(final int item) {



        Number result = null;

        if (getItemCount() > item) {

            result = this.data.getValue(item);

        }

        return result;



    }



    /**

     * Returns the data value associated with a key.

     *

     * @param key  the key (<code>null</code> not permitted).

     *

     * @return the value (possibly <code>null</code>).

     */

    public Number getValue(final Comparable key) {



        // check arguments...

        if (key == null) {

            throw new IllegalArgumentException("PieDataset: null key not allowed.");

        }



        // fetch the value...

        return this.data.getValue(key);



    }



    /**

     * Sets the data value for a key.

     *

     * @param key  the key.

     * @param value  the value.

     */

    public void setValue(final Comparable key, final Number value) {



        this.data.setValue(key, value);

        fireDatasetChanged();



    }



    /**

     * Sets the data value for a key.

     *

     * @param key  the key.

     * @param value  the value.

     */

    public void setValue(final Comparable key, final double value) {



        setValue(key, new Double(value));



    }



    /**

     * Tests if this object is equal to another.

     *

     * @param o  the other object.

     *

     * @return A boolean.

     */

    public boolean equals(final Object o) {



        if (o == null) {

            return false;

        }

        if (o == this) {

            return true;

        }



        if (!(o instanceof PieDataset)) {

            return false;

        }

        final PieDataset pd = (PieDataset) o;

        final int count = getItemCount();

        if (pd.getItemCount() != count) {

            return false;

        }



        for (int i = 0; i < count; i++) {

            final Comparable k1 = getKey(i);

            final Comparable k2 = pd.getKey(i);

            if (!k1.equals(k2)) {

                return false;

            }



            final Number v1 = getValue(i);

            final Number v2 = pd.getValue(i);

            if (v1 == null) {

                if (v2 != null) {

                    return false;

                }

            }

            else {

                if (!v1.equals(v2)) {

                    return false;

                }

            }

        }

        return true;



    }



    /**

     * Returns a hash code.

     * 

     * @return a hash code.

     */

    public int hashCode() {

        return this.data.hashCode();

    }



    /**

     * Returns a clone.

     * 

     * @return A clone.

     * 

     * @throws CloneNotSupportedException This class will not throw this exception, but subclasses

     *         (if any) might.

     */

    public Object clone() throws CloneNotSupportedException {

        final DefaultPieDataset clone = (DefaultPieDataset) super.clone();

        clone.data = (DefaultKeyedValues) this.data.clone();

        return clone;    

    }

    

}

