/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2007, 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.]
 *
 * ----------------
 * ChartEntity.java
 * ----------------
 * (C) Copyright 2002-2007, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   Richard Atkinson;
 *                   Xavier Poinsard;
 *                   Robert Fuller;
 *
 * Changes:
 * --------
 * 23-May-2002 : Version 1 (DG);
 * 12-Jun-2002 : Added Javadoc comments (DG);
 * 26-Jun-2002 : Added methods for image maps (DG);
 * 05-Aug-2002 : Added constructor and accessors for URL support in image maps
 *               Added getImageMapAreaTag() - previously in subclasses (RA);
 * 05-Sep-2002 : Added getImageMapAreaTag(boolean) to support OverLIB for 
 *               tooltips http://www.bosrup.com/web/overlib (RA);
 * 03-Oct-2002 : Fixed errors reported by Checkstyle (DG);
 * 08-Oct-2002 : Changed getImageMapAreaTag to use title instead of alt 
 *               attribute so HTML image maps now work in Mozilla and Opera as 
 *               well as Internet Explorer (RA);
 * 13-Mar-2003 : Change getImageMapAreaTag to only return a tag when there is a
 *               tooltip or URL, as suggested by Xavier Poinsard (see Feature 
 *               Request 688079) (DG);
 * 12-Aug-2003 : Added support for custom image maps using 
 *               ToolTipTagFragmentGenerator and URLTagFragmentGenerator (RA);
 * 02-Sep-2003 : Incorporated fix (791901) submitted by Robert Fuller (DG);
 * 19-May-2004 : Added equals() method and implemented Cloneable and 
 *               Serializable (DG);
 * 29-Sep-2004 : Implemented PublicCloneable (DG);
 * 13-Jan-2005 : Fixed for compliance with XHTML 1.0 (DG);
 * 18-Apr-2005 : Use StringBuffer (DG);
 * 20-Apr-2005 : Added toString() implementation (DG);
 * ------------- JFREECHART 1.0.x ---------------------------------------------
 * 06-Feb-2007 : API doc update (DG);
 * 13-Nov-2007 : Reorganised equals(), implemented hashCode (DG);
 *
 */

package org.jfree.chart.entity;

import java.awt.Shape;
import java.awt.geom.PathIterator;
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.HashUtilities;
import org.jfree.chart.imagemap.ToolTipTagFragmentGenerator;
import org.jfree.chart.imagemap.URLTagFragmentGenerator;
import org.jfree.io.SerialUtilities;
import org.jfree.util.ObjectUtilities;
import org.jfree.util.PublicCloneable;

/**
 * A class that captures information about some component of a chart (a bar, 
 * line etc).
 */
public class ChartEntity implements Cloneable, PublicCloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -4445994133561919083L;
    
    /** The area occupied by the entity (in Java 2D space). */
    private transient Shape area;

    /** The tool tip text for the entity. */
    private String toolTipText;

    /** The URL text for the entity. */
    private String urlText;

    /**
     * Creates a new chart entity.
     *
     * @param area  the area (<code>null</code> not permitted).
     */
    public ChartEntity(Shape area) {
        // defer argument checks...
        this(area, null);
    }

    /**
     * Creates a new chart entity.
     *
     * @param area  the area (<code>null</code> not permitted).
     * @param toolTipText  the tool tip text (<code>null</code> permitted).
     */
    public ChartEntity(Shape area, String toolTipText) {
        // defer argument checks...
        this(area, toolTipText, null);
    }

    /**
     * Creates a new entity.
     *
     * @param area  the area (<code>null</code> not permitted).
     * @param toolTipText  the tool tip text (<code>null</code> permitted).
     * @param urlText  the URL text for HTML image maps (<code>null</code> 
     *                 permitted).
     */
    public ChartEntity(Shape area, String toolTipText, String urlText) {
        if (area == null) {
            throw new IllegalArgumentException("Null 'area' argument.");   
        }
        this.area = area;
        this.toolTipText = toolTipText;
        this.urlText = urlText;
    }

    /**
     * Returns the area occupied by the entity (in Java 2D space).
     *
     * @return The area (never <code>null</code>).
     */
    public Shape getArea() {
        return this.area;
    }

    /**
     * Sets the area for the entity.
     * <P>
     * This class conveys information about chart entities back to a client.
     * Setting this area doesn't change the entity (which has already been
     * drawn).
     *
     * @param area  the area (<code>null</code> not permitted).
     */
    public void setArea(Shape area) {
        if (area == null) {
            throw new IllegalArgumentException("Null 'area' argument.");   
        }
        this.area = area;
    }

    /**
     * Returns the tool tip text for the entity.
     *
     * @return The tool tip text (possibly <code>null</code>).
     */
    public String getToolTipText() {
        return this.toolTipText;
    }

    /**
     * Sets the tool tip text.
     *
     * @param text  the text (<code>null</code> permitted).
     */
    public void setToolTipText(String text) {
        this.toolTipText = text;
    }

    /**
     * Returns the URL text for the entity.
     *
     * @return The URL text (possibly <code>null</code>).
     */
    public String getURLText() {
        return this.urlText;
    }

    /**
     * Sets the URL text.
     *
     * @param text the text (<code>null</code> permitted).
     */
    public void setURLText(String text) {
        this.urlText = text;
    }

    /**
     * Returns a string describing the entity area.  This string is intended
     * for use in an AREA tag when generating an image map.
     *
     * @return The shape type (never <code>null</code>).
     */
    public String getShapeType() {
        if (this.area instanceof Rectangle2D) {
            return "rect";
        }
        else {
            return "poly";
        }
    }

    /**
     * Returns the shape coordinates as a string.
     *
     * @return The shape coordinates (never <code>null</code>).
     */
    public String getShapeCoords() {
        if (this.area instanceof Rectangle2D) {
            return getRectCoords((Rectangle2D) this.area);
        }
        else {
            return getPolyCoords(this.area);
        }
    }

    /**
     * Returns a string containing the coordinates (x1, y1, x2, y2) for a given
     * rectangle.  This string is intended for use in an image map.
     *
     * @param rectangle  the rectangle (<code>null</code> not permitted).
     *
     * @return Upper left and lower right corner of a rectangle.
     */
    private String getRectCoords(Rectangle2D rectangle) {
        if (rectangle == null) {
            throw new IllegalArgumentException("Null 'rectangle' argument.");   
        }
        int x1 = (int) rectangle.getX();
        int y1 = (int) rectangle.getY();
        int x2 = x1 + (int) rectangle.getWidth();
        int y2 = y1 + (int) rectangle.getHeight();
        //      fix by rfuller
        if (x2 == x1) {
            x2++;
        }
        if (y2 == y1) {
            y2++;
        }
        //      end fix by rfuller
        return x1 + "," + y1 + "," + x2 + "," + y2;
    }

    /**
     * Returns a string containing the coordinates for a given shape.  This
     * string is intended for use in an image map.
     *
     * @param shape  the shape (<code>null</code> not permitted).
     *
     * @return The coordinates for a given shape as string.
     */
    private String getPolyCoords(Shape shape) {
        if (shape == null) {
            throw new IllegalArgumentException("Null 'shape' argument.");   
        }
        StringBuffer result = new StringBuffer();
        boolean first = true;
        float[] coords = new float[6];
        PathIterator pi = shape.getPathIterator(null, 1.0);
        while (!pi.isDone()) {
            pi.currentSegment(coords);
            if (first) {
                first = false;
                result.append((int) coords[0]);
                result.append(",").append((int) coords[1]);
            }
            else {
                result.append(",");
                result.append((int) coords[0]);
                result.append(",");
                result.append((int) coords[1]);
            }
            pi.next();
        }
        return result.toString();
    }

    /**
     * Returns an HTML image map tag for this entity.  The returned fragment
     * should be <code>XHTML 1.0</code> compliant.
     *
     * @param toolTipTagFragmentGenerator  a generator for the HTML fragment
     *     that will contain the tooltip text (<code>null</code> not permitted 
     *     if this entity contains tooltip information).
     * @param urlTagFragmentGenerator  a generator for the HTML fragment that
     *     will contain the URL reference (<code>null</code> not permitted if 
     *     this entity has a URL).
     * 
     * @return The HTML tag.
     */
    public String getImageMapAreaTag(
            ToolTipTagFragmentGenerator toolTipTagFragmentGenerator,
            URLTagFragmentGenerator urlTagFragmentGenerator) {

        StringBuffer tag = new StringBuffer();
        boolean hasURL = (this.urlText == null ? false 
                : !this.urlText.equals(""));
        boolean hasToolTip = (this.toolTipText == null ? false 
                : !this.toolTipText.equals(""));
        if (hasURL || hasToolTip) {
            tag.append("<area shape=\"" + getShapeType() + "\"" + " coords=\"" 
                    + getShapeCoords() + "\"");
            if (hasToolTip) {
                tag.append(toolTipTagFragmentGenerator.generateToolTipFragment(
                        this.toolTipText));
            }
            if (hasURL) {
                tag.append(urlTagFragmentGenerator.generateURLFragment(
                        this.urlText));
            }
            // if there is a tool tip, we expect it to generate the title and
            // alt values, so we only add an empty alt if there is no tooltip
            if (!hasToolTip) {
                tag.append(" alt=\"\"");
            }
            tag.append("/>");
        }
        return tag.toString();
    }
    
    /**
     * Returns a string representation of the chart entity, useful for 
     * debugging.
     * 
     * @return A string.
     */
    public String toString() {
        StringBuffer buf = new StringBuffer("ChartEntity: ");
        buf.append("tooltip = ");
        buf.append(this.toolTipText);
        return buf.toString();
    }
    
    /**
     * Tests the entity for equality with an arbitrary object.
     * 
     * @param obj  the object to test against (<code>null</code> permitted).
     * 
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;   
        }
        if (!(obj instanceof ChartEntity)) {
            return false;   
        }
        ChartEntity that = (ChartEntity) obj;
        if (!this.area.equals(that.area)) {
            return false;   
        }
        if (!ObjectUtilities.equal(this.toolTipText, that.toolTipText)) {
            return false;   
        }
        if (!ObjectUtilities.equal(this.urlText, that.urlText)) {
            return false;   
        }
        return true;
    }

    /**
     * Returns a hash code for this instance.
     * 
     * @return A hash code.
     */
    public int hashCode() {
        int result = 37;
        result = HashUtilities.hashCode(result, this.toolTipText);
        result = HashUtilities.hashCode(result, this.urlText);
        return result;
    }
    
    /**
     * Returns a clone of the entity.
     * 
     * @return A clone.
     * 
     * @throws CloneNotSupportedException if there is a problem cloning the 
     *         entity.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();    
    }
    
    /**
     * Provides serialization support.
     *
     * @param stream  the output stream.
     *
     * @throws IOException  if there is an I/O error.
     */
    private void writeObject(ObjectOutputStream stream) throws IOException {
        stream.defaultWriteObject();
        SerialUtilities.writeShape(this.area, stream);
     }

    /**
     * Provides serialization support.
     *
     * @param stream  the input stream.
     *
     * @throws IOException  if there is an I/O error.
     * @throws ClassNotFoundException  if there is a classpath problem.
     */
    private void readObject(ObjectInputStream stream) 
        throws IOException, ClassNotFoundException {
        stream.defaultReadObject();
        this.area = SerialUtilities.readShape(stream);
    }

}