/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2006, 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.] * * ------------------- * CrosshairState.java * ------------------- * (C) Copyright 2002-2006, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * $Id: CrosshairState.java,v 1.3.2.2 2006/08/24 09:22:28 mungady Exp $ * * Changes * ------- * 24-Jan-2002 : Version 1 (DG); * 05-Mar-2002 : Added Javadoc comments (DG); * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG); * 19-Sep-2003 : Modified crosshair distance calculation (DG); * 04-Dec-2003 : Crosshair anchor point now stored outside chart since it is * dependent on the display target (DG); * 25-Feb-2004 : Replaced CrosshairInfo --> CrosshairState (DG); * */ package org.jfree.chart.plot; import java.awt.geom.Point2D; /** * Maintains state information about crosshairs on a plot. */ public class CrosshairState { /** * A flag that controls whether the distance is calculated in data space * or Java2D space. */ private boolean calculateDistanceInDataSpace = false; /** The x-value (in data space) for the anchor point. */ private double anchorX; /** The y-value (in data space) for the anchor point. */ private double anchorY; /** The anchor point in Java2D space - if null, don't update crosshair. */ private Point2D anchor; /** The x-value for the crosshair point. */ private double crosshairX; /** The y-value for the crosshair point. */ private double crosshairY; /** * The smallest distance so far between the anchor point and a data point. */ private double distance; /** * Default constructor. */ public CrosshairState() { this(false); } /** * Creates a new info object. * * @param calculateDistanceInDataSpace a flag that controls whether the * distance is calculated in data * space or Java2D space. */ public CrosshairState(boolean calculateDistanceInDataSpace) { this.calculateDistanceInDataSpace = calculateDistanceInDataSpace; } /** * Sets the distance between the anchor point and the current crosshair * point. As each data point is processed, its distance to the anchor * point is compared with this value and, if it is closer, the data point * becomes the new crosshair point. * * @param distance the distance. */ public void setCrosshairDistance(double distance) { this.distance = distance; } /** * Evaluates a data point and if it is the closest to the anchor point it * becomes the new crosshair point. *
* To understand this method, you need to know the context in which it will * be called. An instance of this class is passed to an * {@link org.jfree.chart.renderer.xy.XYItemRenderer} as * each data point is plotted. As the point is plotted, it is passed to * this method to see if it should be the new crosshair point. * * @param x x coordinate (measured against the domain axis). * @param y y coordinate (measured against the range axis). * @param transX x translated into Java2D space. * @param transY y translated into Java2D space. * @param orientation the plot orientation. */ public void updateCrosshairPoint(double x, double y, double transX, double transY, PlotOrientation orientation) { if (this.anchor != null) { double d = 0.0; if (this.calculateDistanceInDataSpace) { d = (x - this.anchorX) * (x - this.anchorX) + (y - this.anchorY) * (y - this.anchorY); } else { double xx = this.anchor.getX(); double yy = this.anchor.getY(); if (orientation == PlotOrientation.HORIZONTAL) { double temp = yy; yy = xx; xx = temp; } d = (transX - xx) * (transX - xx) + (transY - yy) * (transY - yy); } if (d < this.distance) { this.crosshairX = x; this.crosshairY = y; this.distance = d; } } } /** * Evaluates an x-value and if it is the closest to the anchor point it * becomes the new crosshair point. *
* Used in cases where only the x-axis is numerical. * * @param candidateX x position of the candidate for the new crosshair * point. */ public void updateCrosshairX(double candidateX) { double d = Math.abs(candidateX - this.anchorX); if (d < this.distance) { this.crosshairX = candidateX; this.distance = d; } } /** * Evaluates a y-value and if it is the closest to the anchor point it * becomes the new crosshair point. *
* Used in cases where only the y-axis is numerical. * * @param candidateY y position of the candidate for the new crosshair * point. */ public void updateCrosshairY(double candidateY) { double d = Math.abs(candidateY - this.anchorY); if (d < this.distance) { this.crosshairY = candidateY; this.distance = d; } } /** * Sets the anchor point. This is usually the mouse click point in a chart * panel, and the crosshair point will often be the data item that is * closest to the anchor point. * * @param anchor the anchor point. */ public void setAnchor(Point2D anchor) { this.anchor = anchor; } /** * Get the x-value for the crosshair point. * * @return The x position of the crosshair point. */ public double getCrosshairX() { return this.crosshairX; } /** * Sets the x coordinate for the crosshair. This is the coordinate in data * space measured against the domain axis. * * @param x the coordinate. */ public void setCrosshairX(double x) { this.crosshairX = x; } /** * Get the y-value for the crosshair point. This is the coordinate in data * space measured against the range axis. * * @return The y position of the crosshair point. */ public double getCrosshairY() { return this.crosshairY; } /** * Sets the y coordinate for the crosshair. * * @param y the y coordinate. */ public void setCrosshairY(double y) { this.crosshairY = y; } }