# CategoryPointerAnnotation.java

    /* ===========================================================
     * 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.]
     *
     * ------------------------------
     * CategoryPointerAnnotation.java
     * ------------------------------
     * (C) Copyright 2006, 2007, by Object Refinery Limited.
     *
     * Original Author:  David Gilbert (for Object Refinery Limited);
     * Contributor(s):   -;
     *
     * Changes:
     * --------
     * 02-Oct-2006 : Version 1 (DG);
     * 06-Mar-2007 : Implemented hashCode() (DG);
     *
     */

    package org.jfree.chart.annotations;

    import java.awt.BasicStroke;
    import java.awt.Color;
    import java.awt.Graphics2D;
    import java.awt.Paint;
    import java.awt.Stroke;
    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.HashUtilities;
    import org.jfree.chart.axis.CategoryAxis;
    import org.jfree.chart.axis.ValueAxis;
    import org.jfree.chart.plot.CategoryPlot;
    import org.jfree.chart.plot.Plot;
    import org.jfree.chart.plot.PlotOrientation;
    import org.jfree.data.category.CategoryDataset;
    import org.jfree.io.SerialUtilities;
    import org.jfree.text.TextUtilities;
    import org.jfree.ui.RectangleEdge;
    import org.jfree.util.ObjectUtilities;
    import org.jfree.util.PublicCloneable;

    /**
     * An arrow and label that can be placed on a {@link CategoryPlot}.  The arrow
     * is drawn at a user-definable angle so that it points towards the (category,
     * value) location for the annotation.
     * <p>
     * The arrow length (and its offset from the (category, value) location) is
     * controlled by the tip radius and the base radius attributes.  Imagine two
     * circles around the (category, value) coordinate: the inner circle defined by
     * the tip radius, and the outer circle defined by the base radius.  Now, draw
     * the arrow starting at some point on the outer circle (the point is
     * determined by the angle), with the arrow tip being drawn at a corresponding
     * point on the inner circle.
     *
     * @since 1.0.3
     */
    public class CategoryPointerAnnotation extends CategoryTextAnnotation
                                     implements Cloneable, PublicCloneable,
                                                Serializable {

        /** For serialization. */
        private static final long serialVersionUID = -4031161445009858551L;

        /** The default tip radius (in Java2D units). */
        public static final double DEFAULT_TIP_RADIUS = 10.0;

        /** The default base radius (in Java2D units). */
        public static final double DEFAULT_BASE_RADIUS = 30.0;

        /** The default label offset (in Java2D units). */
        public static final double DEFAULT_LABEL_OFFSET = 3.0;

        /** The default arrow length (in Java2D units). */
        public static final double DEFAULT_ARROW_LENGTH = 5.0;

        /** The default arrow width (in Java2D units). */
        public static final double DEFAULT_ARROW_WIDTH = 3.0;

        /** The angle of the arrow's line (in radians). */
        private double angle;

        /**
         * The radius from the (x, y) point to the tip of the arrow (in Java2D
         * units).
         */
        private double tipRadius;

        /**
         * The radius from the (x, y) point to the start of the arrow line (in
         * Java2D units).
         */
        private double baseRadius;

        /** The length of the arrow head (in Java2D units). */
        private double arrowLength;

        /** The arrow width (in Java2D units, per side). */
        private double arrowWidth;

        /** The arrow stroke. */
        private transient Stroke arrowStroke;

        /** The arrow paint. */
        private transient Paint arrowPaint;

        /** The radius from the base point to the anchor point for the label. */
        private double labelOffset;

        /**
         * Creates a new label and arrow annotation.
         *
         * @param label  the label (<code>null</code> permitted).
         * @param key  the category key.
         * @param value  the y-value (measured against the chart's range axis).
         * @param angle  the angle of the arrow's line (in radians).
         */
        public CategoryPointerAnnotation(String label, Comparable key, double value,
                double angle) {

            super(label, key, value);
            this.angle = angle;
            this.tipRadius = DEFAULT_TIP_RADIUS;
            this.baseRadius = DEFAULT_BASE_RADIUS;
            this.arrowLength = DEFAULT_ARROW_LENGTH;
            this.arrowWidth = DEFAULT_ARROW_WIDTH;
            this.labelOffset = DEFAULT_LABEL_OFFSET;
            this.arrowStroke = new BasicStroke(1.0f);
            this.arrowPaint = Color.black;

        }

        /**
         * Returns the angle of the arrow.
         *
         * @return The angle (in radians).
         *
         * @see #setAngle(double)
         */
        public double getAngle() {
            return this.angle;
        }

        /**
         * Sets the angle of the arrow.
         *
         * @param angle  the angle (in radians).
         *
         * @see #getAngle()
         */
        public void setAngle(double angle) {
            this.angle = angle;
        }

        /**
         * Returns the tip radius.
         *
         * @return The tip radius (in Java2D units).
         *
         * @see #setTipRadius(double)
         */
        public double getTipRadius() {
            return this.tipRadius;
        }

        /**
         * Sets the tip radius.
         *
         * @param radius  the radius (in Java2D units).
         *
         * @see #getTipRadius()
         */
        public void setTipRadius(double radius) {
            this.tipRadius = radius;
        }

        /**
         * Returns the base radius.
         *
         * @return The base radius (in Java2D units).
         *
         * @see #setBaseRadius(double)
         */
        public double getBaseRadius() {
            return this.baseRadius;
        }

        /**
         * Sets the base radius.
         *
         * @param radius  the radius (in Java2D units).
         *
         * @see #getBaseRadius()
         */
        public void setBaseRadius(double radius) {
            this.baseRadius = radius;
        }

        /**
         * Returns the label offset.
         *
         * @return The label offset (in Java2D units).
         *
         * @see #setLabelOffset(double)
         */
        public double getLabelOffset() {
            return this.labelOffset;
        }

        /**
         * Sets the label offset (from the arrow base, continuing in a straight
         * line, in Java2D units).
         *
         * @param offset  the offset (in Java2D units).
         *
         * @see #getLabelOffset()
         */
        public void setLabelOffset(double offset) {
            this.labelOffset = offset;
        }

        /**
         * Returns the arrow length.
         *
         * @return The arrow length.
         *
         * @see #setArrowLength(double)
         */
        public double getArrowLength() {
            return this.arrowLength;
        }

        /**
         * Sets the arrow length.
         *
         * @param length  the length.
         *
         * @see #getArrowLength()
         */
        public void setArrowLength(double length) {
            this.arrowLength = length;
        }

        /**
         * Returns the arrow width.
         *
         * @return The arrow width (in Java2D units).
         *
         * @see #setArrowWidth(double)
         */
        public double getArrowWidth() {
            return this.arrowWidth;
        }

        /**
         * Sets the arrow width.
         *
         * @param width  the width (in Java2D units).
         *
         * @see #getArrowWidth()
         */
        public void setArrowWidth(double width) {
            this.arrowWidth = width;
        }

        /**
         * Returns the stroke used to draw the arrow line.
         *
         * @return The arrow stroke (never <code>null</code>).
         *
         * @see #setArrowStroke(Stroke)
         */
        public Stroke getArrowStroke() {
            return this.arrowStroke;
        }

        /**
         * Sets the stroke used to draw the arrow line.
         *
         * @param stroke  the stroke (<code>null</code> not permitted).
         *
         * @see #getArrowStroke()
         */
        public void setArrowStroke(Stroke stroke) {
            if (stroke == null) {
                throw new IllegalArgumentException("Null 'stroke' not permitted.");
            }
            this.arrowStroke = stroke;
        }

        /**
         * Returns the paint used for the arrow.
         *
         * @return The arrow paint (never <code>null</code>).
         *
         * @see #setArrowPaint(Paint)
         */
        public Paint getArrowPaint() {
            return this.arrowPaint;
        }

        /**
         * Sets the paint used for the arrow.
         *
         * @param paint  the arrow paint (<code>null</code> not permitted).
         *
         * @see #getArrowPaint()
         */
        public void setArrowPaint(Paint paint) {
            if (paint == null) {
                throw new IllegalArgumentException("Null 'paint' argument.");
            }
            this.arrowPaint = paint;
        }

        /**
         * Draws the annotation.
         *
         * @param g2  the graphics device.
         * @param plot  the plot.
         * @param dataArea  the data area.
         * @param domainAxis  the domain axis.
         * @param rangeAxis  the range axis.
         */
        public void draw(Graphics2D g2, CategoryPlot plot, Rectangle2D dataArea,
                CategoryAxis domainAxis, ValueAxis rangeAxis) {

            PlotOrientation orientation = plot.getOrientation();
            RectangleEdge domainEdge = Plot.resolveDomainAxisLocation(
                    plot.getDomainAxisLocation(), orientation);
            RectangleEdge rangeEdge = Plot.resolveRangeAxisLocation(
                    plot.getRangeAxisLocation(), orientation);
            CategoryDataset dataset = plot.getDataset();
            int catIndex = dataset.getColumnIndex(getCategory());
            int catCount = dataset.getColumnCount();
            double j2DX = domainAxis.getCategoryMiddle(catIndex, catCount,
                    dataArea, domainEdge);
            double j2DY = rangeAxis.valueToJava2D(getValue(), dataArea, rangeEdge);
            if (orientation == PlotOrientation.HORIZONTAL) {
                double temp = j2DX;
                j2DX = j2DY;
                j2DY = temp;
            }
            double startX = j2DX + Math.cos(this.angle) * this.baseRadius;
            double startY = j2DY + Math.sin(this.angle) * this.baseRadius;

            double endX = j2DX + Math.cos(this.angle) * this.tipRadius;
            double endY = j2DY + Math.sin(this.angle) * this.tipRadius;

            double arrowBaseX = endX + Math.cos(this.angle) * this.arrowLength;
            double arrowBaseY = endY + Math.sin(this.angle) * this.arrowLength;

            double arrowLeftX = arrowBaseX
                + Math.cos(this.angle + Math.PI / 2.0) * this.arrowWidth;
            double arrowLeftY = arrowBaseY
                + Math.sin(this.angle + Math.PI / 2.0) * this.arrowWidth;

            double arrowRightX = arrowBaseX
                - Math.cos(this.angle + Math.PI / 2.0) * this.arrowWidth;
            double arrowRightY = arrowBaseY
                - Math.sin(this.angle + Math.PI / 2.0) * this.arrowWidth;

            GeneralPath arrow = new GeneralPath();
            arrow.moveTo((float) endX, (float) endY);
            arrow.lineTo((float) arrowLeftX, (float) arrowLeftY);
            arrow.lineTo((float) arrowRightX, (float) arrowRightY);
            arrow.closePath();

            g2.setStroke(this.arrowStroke);
            g2.setPaint(this.arrowPaint);
            Line2D line = new Line2D.Double(startX, startY, endX, endY);
            g2.draw(line);
            g2.fill(arrow);

            // draw the label
            g2.setFont(getFont());
            g2.setPaint(getPaint());
            double labelX = j2DX
                + Math.cos(this.angle) * (this.baseRadius + this.labelOffset);
            double labelY = j2DY
                + Math.sin(this.angle) * (this.baseRadius + this.labelOffset);
            /* Rectangle2D hotspot = */ TextUtilities.drawAlignedString(getText(),
                    g2, (float) labelX, (float) labelY, getTextAnchor());
            // TODO: implement the entity for the annotation

        }

        /**
         * Tests this annotation for equality with an arbitrary object.
         *
         * @param obj  the object (<code>null</code> permitted).
         *
         * @return <code>true</code> or <code>false</code>.
         */
        public boolean equals(Object obj) {

            if (obj == this) {
                return true;
            }
            if (!(obj instanceof CategoryPointerAnnotation)) {
                return false;
            }
            if (!super.equals(obj)) {
                return false;
            }
            CategoryPointerAnnotation that = (CategoryPointerAnnotation) obj;
            if (this.angle != that.angle) {
                return false;
            }
            if (this.tipRadius != that.tipRadius) {
                return false;
            }
            if (this.baseRadius != that.baseRadius) {
                return false;
            }
            if (this.arrowLength != that.arrowLength) {
                return false;
            }
            if (this.arrowWidth != that.arrowWidth) {
                return false;
            }
            if (!this.arrowPaint.equals(that.arrowPaint)) {
                return false;
            }
            if (!ObjectUtilities.equal(this.arrowStroke, that.arrowStroke)) {
                return false;
            }
            if (this.labelOffset != that.labelOffset) {
                return false;
            }
            return true;
        }

        /**
         * Returns a hash code for this instance.
         *
         * @return A hash code.
         */
        public int hashCode() {
            int result = 193;
            long temp = Double.doubleToLongBits(this.angle);
            result = 37 * result + (int) (temp ^ (temp >>> 32));
            temp = Double.doubleToLongBits(this.tipRadius);
            result = 37 * result + (int) (temp ^ (temp >>> 32));
            temp = Double.doubleToLongBits(this.baseRadius);
            result = 37 * result + (int) (temp ^ (temp >>> 32));
            temp = Double.doubleToLongBits(this.arrowLength);
            result = 37 * result + (int) (temp ^ (temp >>> 32));
            temp = Double.doubleToLongBits(this.arrowWidth);
            result = 37 * result + (int) (temp ^ (temp >>> 32));
            result = 37 * result + HashUtilities.hashCodeForPaint(this.arrowPaint);
            result = 37 * result + this.arrowStroke.hashCode();
            temp = Double.doubleToLongBits(this.labelOffset);
            result = 37 * result + (int) (temp ^ (temp >>> 32));
            return result;
        }

        /**
         * Returns a clone of the annotation.
         *
         * @return A clone.
         *
         * @throws CloneNotSupportedException  if the annotation can't be cloned.
         */
        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.writePaint(this.arrowPaint, stream);
            SerialUtilities.writeStroke(this.arrowStroke, 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.arrowPaint = SerialUtilities.readPaint(stream);
            this.arrowStroke = SerialUtilities.readStroke(stream);
        }

    }