jfreechart example source code file (CategoryCrosshairState.java)

This example jfreechart source code file (CategoryCrosshairState.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - jfreechart tags/keywords

awt, categorycrosshairstate, categorycrosshairstate, comparable, comparable, crosshairstate, geometry, plotorientation, plotorientation, point2d, point2d

The jfreechart CategoryCrosshairState.java source code

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, 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.]
 *
 * ---------------------------
 * CategoryCrosshairState.java
 * ---------------------------
 * (C) Copyright 2008, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 26-Jun-2008 : Version 1 (DG);
 *
 */

package org.jfree.chart.plot;

import java.awt.geom.Point2D;

import org.jfree.chart.renderer.category.CategoryItemRenderer;

/**
 * Represents state information for the crosshairs in a {@link CategoryPlot}.
 * An instance of this class is created at the start of the rendering process,
 * and updated as each data item is rendered.  At the end of the rendering
 * process, this class holds the row key, column key and value for the
 * crosshair location.
 *
 * @since 1.0.11
 */
public class CategoryCrosshairState extends CrosshairState {

    /**
     * The row key for the crosshair point.
     */
    private Comparable rowKey;

    /**
     * The column key for the crosshair point.
     */
    private Comparable columnKey;

    /**
     * Creates a new instance.
     */
    public CategoryCrosshairState() {
        this.rowKey = null;
        this.columnKey = null;
    }

    /**
     * Returns the row key.
     *
     * @return The row key.
     */
    public Comparable getRowKey() {
        return this.rowKey;
    }

    /**
     * Sets the row key.
     *
     * @param key  the row key.
     */
    public void setRowKey(Comparable key) {
        this.rowKey = key;
    }

    /**
     * Returns the column key.
     *
     * @return The column key.
     */
    public Comparable getColumnKey() {
        return this.columnKey;
    }

    /**
     * Sets the column key.
     *
     * @param key  the key.
     */
    public void setColumnKey(Comparable key) {
        this.columnKey = key;
    }

    /**
     * Evaluates a data point from a {@link CategoryItemRenderer} and if it is
     * the closest to the anchor point it becomes the new crosshair point.
     *
     * @param rowKey  the row key.
     * @param columnKey  the column key.
     * @param value  y coordinate (measured against the range axis).
     * @param datasetIndex  the dataset index for this point.
     * @param transX  x translated into Java2D space.
     * @param transY  y translated into Java2D space.
     * @param orientation  the plot orientation.
     */
    public void updateCrosshairPoint(Comparable rowKey, Comparable columnKey,
            double value, int datasetIndex, double transX, double transY,
            PlotOrientation orientation) {

        Point2D anchor = getAnchor();
        if (anchor != null) {
            double xx = anchor.getX();
            double yy = anchor.getY();
            if (orientation == PlotOrientation.HORIZONTAL) {
                double temp = yy;
                yy = xx;
                xx = temp;
            }
            double d = (transX - xx) * (transX - xx)
                    + (transY - yy) * (transY - yy);

            if (d < getCrosshairDistance()) {
                this.rowKey = rowKey;
                this.columnKey = columnKey;
                setCrosshairY(value);
                setDatasetIndex(datasetIndex);
                setCrosshairDistance(d);
            }
        }

    }

    /**
     * Updates only the crosshair row and column keys (this is for the case
     * where the range crosshair does NOT lock onto the nearest data value).
     *
     * @param rowKey  the row key.
     * @param columnKey  the column key.
     * @param datasetIndex  the dataset axis index.
     * @param transX  the translated x-value.
     * @param orientation  the plot orientation.
     */
    public void updateCrosshairX(Comparable rowKey, Comparable columnKey,
            int datasetIndex, double transX, PlotOrientation orientation) {

        Point2D anchor = getAnchor();
        if (anchor != null) {
            double anchorX = anchor.getX();
            if (orientation == PlotOrientation.HORIZONTAL) {
                anchorX = anchor.getY();
            }
            double d = Math.abs(transX - anchorX);
            if (d < getCrosshairDistance()) {
                this.rowKey = rowKey;
                this.columnKey = columnKey;
                setDatasetIndex(datasetIndex);
                setCrosshairDistance(d);
            }
        }

    }

}