/* ===========================================================
 * 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.]
 *
 * ---------
 * Plot.java
 * ---------
 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   Sylvain Vieujot;
 *                   Jeremy Bowman;
 *                   Andreas Schneider;
 *                   Gideon Krause;
 *                   Nicolas Brodu;
 *
 * $Id: Plot.java,v 1.18.2.3 2005/10/25 20:52:07 mungady Exp $
 *
 * Changes (from 21-Jun-2001)
 * --------------------------
 * 21-Jun-2001 : Removed redundant JFreeChart parameter from constructors (DG);
 * 18-Sep-2001 : Updated header info and fixed DOS encoding problem (DG);
 * 19-Oct-2001 : Moved series paint and stroke methods from JFreeChart 
 *               class (DG);
 * 23-Oct-2001 : Created renderer for LinePlot class (DG);
 * 07-Nov-2001 : Changed type names for ChartChangeEvent (DG);
 *               Tidied up some Javadoc comments (DG);
 * 13-Nov-2001 : Changes to allow for null axes on plots such as PiePlot (DG);
 *               Added plot/axis compatibility checks (DG);
 * 12-Dec-2001 : Changed constructors to protected, and removed unnecessary 
 *               'throws' clauses (DG);
 * 13-Dec-2001 : Added tooltips (DG);
 * 22-Jan-2002 : Added handleClick() method, as part of implementation for 
 *               crosshairs (DG);
 *               Moved tooltips reference into ChartInfo class (DG);
 * 23-Jan-2002 : Added test for null axes in chartChanged() method, thanks 
 *               to Barry Evans for the bug report (number 506979 on 
 *               SourceForge) (DG);
 *               Added a zoom() method (DG);
 * 05-Feb-2002 : Updated setBackgroundPaint(), setOutlineStroke() and 
 *               setOutlinePaint() to better handle null values, as suggested 
 *               by Sylvain Vieujot (DG);
 * 06-Feb-2002 : Added background image, plus alpha transparency for background
 *               and foreground (DG);
 * 06-Mar-2002 : Added AxisConstants interface (DG);
 * 26-Mar-2002 : Changed zoom method from empty to abstract (DG);
 * 23-Apr-2002 : Moved dataset from JFreeChart class (DG);
 * 11-May-2002 : Added ShapeFactory interface for getShape() methods, 
 *               contributed by Jeremy Bowman (DG);
 * 28-May-2002 : Fixed bug in setSeriesPaint(int, Paint) for subplots (AS);
 * 25-Jun-2002 : Removed redundant imports (DG);
 * 30-Jul-2002 : Added 'no data' message for charts with null or empty 
 *               datasets (DG);
 * 21-Aug-2002 : Added code to extend series array if necessary (refer to 
 *               SourceForge bug id 594547 for details) (DG);
 * 17-Sep-2002 : Fixed bug in getSeriesOutlineStroke() method, reported by 
 *               Andreas Schroeder (DG);
 * 23-Sep-2002 : Added getLegendItems() abstract method (DG);
 * 24-Sep-2002 : Removed firstSeriesIndex, subplots now use their own paint 
 *               settings, there is a new mechanism for the legend to collect 
 *               the legend items (DG);
 * 27-Sep-2002 : Added dataset group (DG);
 * 14-Oct-2002 : Moved listener storage into EventListenerList.  Changed some 
 *               abstract methods to empty implementations (DG);
 * 28-Oct-2002 : Added a getBackgroundImage() method (DG);
 * 21-Nov-2002 : Added a plot index for identifying subplots in combined and 
 *               overlaid charts (DG);
 * 22-Nov-2002 : Changed all attributes from 'protected' to 'private'.  Added 
 *               dataAreaRatio attribute from David M O'Donnell's code (DG);
 * 09-Jan-2003 : Integrated fix for plot border contributed by Gideon 
 *               Krause (DG);
 * 17-Jan-2003 : Moved to com.jrefinery.chart.plot (DG);
 * 23-Jan-2003 : Removed one constructor (DG);
 * 26-Mar-2003 : Implemented Serializable (DG);
 * 14-Jul-2003 : Moved the dataset and secondaryDataset attributes to the 
 *               CategoryPlot and XYPlot classes (DG);
 * 21-Jul-2003 : Moved DrawingSupplier from CategoryPlot and XYPlot up to this 
 *               class (DG);
 * 20-Aug-2003 : Implemented Cloneable (DG);
 * 11-Sep-2003 : Listeners and clone (NB);
 * 29-Oct-2003 : Added workaround for font alignment in PDF output (DG);
 * 03-Dec-2003 : Modified draw method to accept anchor (DG);
 * 12-Mar-2004 : Fixed clipping bug in drawNoDataMessage() method (DG);
 * 07-Apr-2004 : Modified string bounds calculation (DG);
 * 04-Nov-2004 : Added default shapes for legend items (DG);
 * 25-Nov-2004 : Some changes to the clone() method implementation (DG);
 * 23-Feb-2005 : Implemented new LegendItemSource interface (and also
 *               PublicCloneable) (DG);
 * 21-Apr-2005 : Replaced Insets with RectangleInsets (DG);
 * 05-May-2005 : Removed unused draw() method (DG);
 * 06-Jun-2005 : Fixed bugs in equals() method (DG);
 * 01-Sep-2005 : Moved dataAreaRatio from here to ContourPlot (DG);
 *
 */

package org.jfree.chart.plot;

import java.awt.AlphaComposite;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Composite;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Paint;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

import javax.swing.event.EventListenerList;

import org.jfree.chart.LegendItemCollection;
import org.jfree.chart.LegendItemSource;
import org.jfree.chart.axis.AxisLocation;
import org.jfree.chart.event.AxisChangeEvent;
import org.jfree.chart.event.AxisChangeListener;
import org.jfree.chart.event.ChartChangeEventType;
import org.jfree.chart.event.PlotChangeEvent;
import org.jfree.chart.event.PlotChangeListener;
import org.jfree.data.general.DatasetChangeEvent;
import org.jfree.data.general.DatasetChangeListener;
import org.jfree.data.general.DatasetGroup;
import org.jfree.io.SerialUtilities;
import org.jfree.text.G2TextMeasurer;
import org.jfree.text.TextBlock;
import org.jfree.text.TextBlockAnchor;
import org.jfree.text.TextUtilities;
import org.jfree.ui.Align;
import org.jfree.ui.RectangleEdge;
import org.jfree.ui.RectangleInsets;
import org.jfree.util.ObjectUtilities;
import org.jfree.util.PaintUtilities;
import org.jfree.util.PublicCloneable;

/**
 * The base class for all plots in JFreeChart.  The 
 * {@link org.jfree.chart.JFreeChart} class delegates the drawing of axes and 
 * data to the plot.  This base class provides facilities common to most plot 
 * types.
 */
public abstract class Plot implements AxisChangeListener,
                                      DatasetChangeListener,
                                      LegendItemSource,
                                      PublicCloneable,
                                      Cloneable,
                                      Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -8831571430103671324L;
    
    /** Useful constant representing zero. */
    public static final Number ZERO = new Integer(0);

    /** The default insets. */
    public static final RectangleInsets DEFAULT_INSETS 
        = new RectangleInsets(4.0, 8.0, 4.0, 8.0);

    /** The default outline stroke. */
    public static final Stroke DEFAULT_OUTLINE_STROKE = new BasicStroke(0.5f);

    /** The default outline color. */
    public static final Paint DEFAULT_OUTLINE_PAINT = Color.gray;

    /** The default foreground alpha transparency. */
    public static final float DEFAULT_FOREGROUND_ALPHA = 1.0f;

    /** The default background alpha transparency. */
    public static final float DEFAULT_BACKGROUND_ALPHA = 1.0f;

    /** The default background color. */
    public static final Paint DEFAULT_BACKGROUND_PAINT = Color.white;

    /** The minimum width at which the plot should be drawn. */
    public static final int MINIMUM_WIDTH_TO_DRAW = 10;

    /** The minimum height at which the plot should be drawn. */
    public static final int MINIMUM_HEIGHT_TO_DRAW = 10;
    
    /** A default box shape for legend items. */
    public static final Shape DEFAULT_LEGEND_ITEM_BOX 
        = new Rectangle2D.Double(-4.0, -4.0, 8.0, 8.0);
    
    /** A default circle shape for legend items. */
    public static final Shape DEFAULT_LEGEND_ITEM_CIRCLE 
        = new Ellipse2D.Double(-4.0, -4.0, 8.0, 8.0);

    /** The parent plot (<code>null</code> if this is the root plot). */
    private Plot parent;

    /** The dataset group (to be used for thread synchronisation). */
    private DatasetGroup datasetGroup;

    /** The message to display if no data is available. */
    private String noDataMessage;

    /** The font used to display the 'no data' message. */
    private Font noDataMessageFont;

    /** The paint used to draw the 'no data' message. */
    private transient Paint noDataMessagePaint;

    /** Amount of blank space around the plot area. */
    private RectangleInsets insets;

    /** The Stroke used to draw an outline around the plot. */
    private transient Stroke outlineStroke;

    /** The Paint used to draw an outline around the plot. */
    private transient Paint outlinePaint;

    /** An optional color used to fill the plot background. */
    private transient Paint backgroundPaint;

    /** An optional image for the plot background. */
    private transient Image backgroundImage;  // not currently serialized

    /** The alignment for the background image. */
    private int backgroundImageAlignment = Align.FIT;

    /** The alpha-transparency for the plot. */
    private float foregroundAlpha;

    /** The alpha transparency for the background paint. */
    private float backgroundAlpha;

    /** The drawing supplier. */
    private DrawingSupplier drawingSupplier;

    /** Storage for registered change listeners. */
    private transient EventListenerList listenerList;

    /**
     * Creates a new plot.
     */
    protected Plot() {

        this.parent = null;
        this.insets = DEFAULT_INSETS;
        this.backgroundPaint = DEFAULT_BACKGROUND_PAINT;
        this.backgroundAlpha = DEFAULT_BACKGROUND_ALPHA;
        this.backgroundImage = null;
        this.outlineStroke = DEFAULT_OUTLINE_STROKE;
        this.outlinePaint = DEFAULT_OUTLINE_PAINT;
        this.foregroundAlpha = DEFAULT_FOREGROUND_ALPHA;

        this.noDataMessage = null;
        this.noDataMessageFont = new Font("SansSerif", Font.PLAIN, 12);
        this.noDataMessagePaint = Color.black;

        this.drawingSupplier = new DefaultDrawingSupplier();

        this.listenerList = new EventListenerList();

    }

    /**
     * Returns the dataset group for the plot (not currently used).
     *
     * @return The dataset group.
     */
    public DatasetGroup getDatasetGroup() {
        return this.datasetGroup;
    }

    /**
     * Sets the dataset group (not currently used).
     *
     * @param group  the dataset group (<code>null</code> permitted).
     */
    protected void setDatasetGroup(DatasetGroup group) {
        this.datasetGroup = group;
    }

    /**
     * Returns the string that is displayed when the dataset is empty or 
     * <code>null</code>.
     *
     * @return The 'no data' message (<code>null</code> possible).
     */
    public String getNoDataMessage() {
        return this.noDataMessage;
    }

    /**
     * Sets the message that is displayed when the dataset is empty or null.
     *
     * @param message  the message (null permitted).
     */
    public void setNoDataMessage(String message) {
        this.noDataMessage = message;
    }

    /**
     * Returns the font used to display the 'no data' message.
     *
     * @return The font.
     */
    public Font getNoDataMessageFont() {
        return this.noDataMessageFont;
    }

    /**
     * Sets the font used to display the 'no data' message.
     *
     * @param font  the font.
     */
    public void setNoDataMessageFont(Font font) {
        this.noDataMessageFont = font;
    }

    /**
     * Returns the paint used to display the 'no data' message.
     *
     * @return The paint.
     */
    public Paint getNoDataMessagePaint() {
        return this.noDataMessagePaint;
    }

    /**
     * Sets the paint used to display the 'no data' message.
     *
     * @param paint  the paint.
     */
    public void setNoDataMessagePaint(Paint paint) {
        this.noDataMessagePaint = paint;
    }

    /**
     * Returns a short string describing the plot type.
     * <P>
     * Note: this gets used in the chart property editing user interface,
     * but there needs to be a better mechanism for identifying the plot type.
     *
     * @return A short string describing the plot type.
     */
    public abstract String getPlotType();

    /**
     * Returns the parent plot (or <code>null</code> if this plot is not part 
     * of a combined plot).
     *
     * @return The parent plot.
     */
    public Plot getParent() {
        return this.parent;
    }

    /**
     * Sets the parent plot.
     *
     * @param parent  the parent plot.
     */
    public void setParent(Plot parent) {
        this.parent = parent;
    }

    /**
     * Returns the root plot.
     *
     * @return The root plot.
     */
    public Plot getRootPlot() {

        Plot p = getParent();
        if (p == null) {
            return this;
        }
        else {
            return p.getRootPlot();
        }