/* ===========================================================
 * 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.]
 *
 * -------------
 * RingPlot.java
 * -------------
 * (C) Copyright 2004, 2005, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limtied);
 * Contributor(s):   -
 *
 * $Id: RingPlot.java,v 1.4.2.4 2005/12/02 11:53:09 mungady Exp $
 *
 * Changes
 * -------
 * 08-Nov-2004 : Version 1 (DG);
 * 22-Feb-2005 : Renamed DonutPlot --> RingPlot (DG);
 * 06-Jun-2005 : Added default constructor and fixed equals() method to handle
 *               GradientPaint (DG);
 * 
 */

package org.jfree.chart.plot;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.geom.Arc2D;
import java.awt.geom.GeneralPath;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

import org.jfree.chart.entity.EntityCollection;
import org.jfree.chart.entity.PieSectionEntity;
import org.jfree.chart.event.PlotChangeEvent;
import org.jfree.chart.labels.PieToolTipGenerator;
import org.jfree.chart.urls.PieURLGenerator;
import org.jfree.data.general.PieDataset;
import org.jfree.io.SerialUtilities;
import org.jfree.ui.RectangleInsets;
import org.jfree.util.ObjectUtilities;
import org.jfree.util.PaintUtilities;
import org.jfree.util.Rotation;
import org.jfree.util.ShapeUtilities;
import org.jfree.util.UnitType;

/**
 * A customised pie plot that leaves a hole in the middle.
 */
public class RingPlot extends PiePlot implements Cloneable, Serializable {
    
    /** For serialization. */
    private static final long serialVersionUID = 1556064784129676620L;
    
    /** 
     * A flag that controls whether or not separators are drawn between the
     * sections of the chart.
     */
    private boolean separatorsVisible;
    
    /** The stroke used to draw separators. */
    private transient Stroke separatorStroke;
    
    /** The paint used to draw separators. */
    private transient Paint separatorPaint;
    
    /** 
     * The length of the inner separator extension (as a percentage of the
     * depth of the sections). 
     */
    private double innerSeparatorExtension;
    
    /** 
     * The length of the outer separator extension (as a percentage of the
     * depth of the sections). 
     */
    private double outerSeparatorExtension;
    
    /**
     * Creates a new plot with a <code>null</code> dataset.
     */
    public RingPlot() {
        this(null);   
    }
    
    /**
     * Creates a new plot for the specified dataset.
     * 
     * @param dataset  the dataset (<code>null</code> permitted).
     */
    public RingPlot(PieDataset dataset) {
        super(dataset);
        this.separatorsVisible = true;
        this.separatorStroke = new BasicStroke(0.5f);
        this.separatorPaint = Color.gray;
        this.innerSeparatorExtension = 0.20;  // twenty percent
        this.outerSeparatorExtension = 0.20;  // twenty percent
    }
    
    /**
     * Returns a flag that indicates whether or not separators are drawn between
     * the sections in the chart.
     * 
     * @return A boolean.
     */
    public boolean getSeparatorsVisible() {
        return this.separatorsVisible;
    }
    
    /**
     * Sets the flag that controls whether or not separators are drawn between 
     * the sections in the chart, and sends a {@link PlotChangeEvent} to all
     * registered listeners.
     * 
     * @param visible  the flag.
     */
    public void setSeparatorsVisible(boolean visible) {
        this.separatorsVisible = visible;
        notifyListeners(new PlotChangeEvent(this));
    }
    
    /**
     * Returns the separator stroke.
     * 
     * @return The stroke (never <code>null</code>).
     */
    public Stroke getSeparatorStroke() {
        return this.separatorStroke;
    }
    
    /**
     * Sets the stroke used to draw the separator between sections.
     * 
     * @param stroke  the stroke (<code>null</code> not permitted).
     */
    public void setSeparatorStroke(Stroke stroke) {
        if (stroke == null) {
            throw new IllegalArgumentException("Null 'stroke' argument.");
        }
        this.separatorStroke = stroke;
        notifyListeners(new PlotChangeEvent(this));
    }
    
    /**
     * Returns the separator paint.
     * 
     * @return The paint (never <code>null</code>).
     */
    public Paint getSeparatorPaint() {
        return this.separatorPaint;
    }
    
    /**
     * Sets the paint used to draw the separator between sections.
     * 
     * @param paint  the paint (<code>null</code> not permitted).
     */
    public void setSeparatorPaint(Paint paint) {
        if (paint == null) {
            throw new IllegalArgumentException("Null 'paint' argument.");
        }
        this.separatorPaint = paint;
        notifyListeners(new PlotChangeEvent(this));
    }
    
    /**
     * Returns the length of the inner extension of the separator line that
     * is drawn between sections, expressed as a percentage of the depth of
     * the section.
     * 
     * @return The inner separator extension (as a percentage).
     */
    public double getInnerSeparatorExtension() {
        return this.innerSeparatorExtension;
    }
    
    /**
     * Sets the length of the inner extension of the separator line that is
     * drawn between sections, as a percentage of the depth of the 
     * sections, and sends a {@link PlotChangeEvent} to all registered 
     * listeners.
     * 
     * @param percent  the percentage.
     */
    public void setInnerSeparatorExtension(double percent) {
        this.innerSeparatorExtension = percent;
        notifyListeners(new PlotChangeEvent(this));
    }
    
    /**
     * Returns the length of the outer extension of the separator line that
     * is drawn between sections, expressed as a percentage of the depth of
     * the section.
     * 
     * @return The outer separator extension (as a percentage).
     */
    public double getOuterSeparatorExtension() {
        return this.outerSeparatorExtension;
    }
    
    /**
     * Sets the length of the outer extension of the separator line that is
     * drawn between sections, as a percentage of the depth of the 
     * sections, and sends a {@link PlotChangeEvent} to all registered 
     * listeners.
     * 
     * @param percent  the percentage.
     */
    public void setOuterSeparatorExtension(double percent) {
        this.outerSeparatorExtension = percent;
        notifyListeners(new PlotChangeEvent(this));