001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2022, by David Gilbert and Contributors.
006 *
007 * Project Info:  http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022 * USA.
023 *
024 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * ---------------------------
028 * CategoryCrosshairState.java
029 * ---------------------------
030 * (C) Copyright 2008-2022, by David Gilbert and Contributors.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.chart.plot;
038
039import java.awt.geom.Point2D;
040
041import org.jfree.chart.renderer.category.CategoryItemRenderer;
042
043/**
044 * Represents state information for the crosshairs in a {@link CategoryPlot}.
045 * An instance of this class is created at the start of the rendering process,
046 * and updated as each data item is rendered.  At the end of the rendering
047 * process, this class holds the row key, column key and value for the
048 * crosshair location.
049 */
050public class CategoryCrosshairState<R extends Comparable<R>, C extends Comparable<C>> 
051        extends CrosshairState {
052
053    /**
054     * The row key for the crosshair point.
055     */
056    private R rowKey;
057
058    /**
059     * The column key for the crosshair point.
060     */
061    private C columnKey;
062
063    /**
064     * Creates a new instance.
065     */
066    public CategoryCrosshairState() {
067        this.rowKey = null;
068        this.columnKey = null;
069    }
070
071    /**
072     * Returns the row key.
073     *
074     * @return The row key.
075     */
076    public R getRowKey() {
077        return this.rowKey;
078    }
079
080    /**
081     * Sets the row key.
082     *
083     * @param key  the row key.
084     */
085    public void setRowKey(R key) {
086        this.rowKey = key;
087    }
088
089    /**
090     * Returns the column key.
091     *
092     * @return The column key.
093     */
094    public C getColumnKey() {
095        return this.columnKey;
096    }
097
098    /**
099     * Sets the column key.
100     *
101     * @param key  the key.
102     */
103    public void setColumnKey(C key) {
104        this.columnKey = key;
105    }
106
107    /**
108     * Evaluates a data point from a {@link CategoryItemRenderer} and if it is
109     * the closest to the anchor point it becomes the new crosshair point.
110     *
111     * @param rowKey  the row key.
112     * @param columnKey  the column key.
113     * @param value  y coordinate (measured against the range axis).
114     * @param datasetIndex  the dataset index for this point.
115     * @param transX  x translated into Java2D space.
116     * @param transY  y translated into Java2D space.
117     * @param orientation  the plot orientation.
118     */
119    public void updateCrosshairPoint(R rowKey, C columnKey,
120            double value, int datasetIndex, double transX, double transY,
121            PlotOrientation orientation) {
122
123        Point2D anchor = getAnchor();
124        if (anchor != null) {
125            double xx = anchor.getX();
126            double yy = anchor.getY();
127            if (orientation == PlotOrientation.HORIZONTAL) {
128                double temp = yy;
129                yy = xx;
130                xx = temp;
131            }
132            double d = (transX - xx) * (transX - xx)
133                    + (transY - yy) * (transY - yy);
134
135            if (d < getCrosshairDistance()) {
136                this.rowKey = rowKey;
137                this.columnKey = columnKey;
138                setCrosshairY(value);
139                setDatasetIndex(datasetIndex);
140                setCrosshairDistance(d);
141            }
142        }
143
144    }
145
146    /**
147     * Updates only the crosshair row and column keys (this is for the case
148     * where the range crosshair does NOT lock onto the nearest data value).
149     *
150     * @param rowKey  the row key.
151     * @param columnKey  the column key.
152     * @param datasetIndex  the dataset axis index.
153     * @param transX  the translated x-value.
154     * @param orientation  the plot orientation.
155     */
156    public void updateCrosshairX(R rowKey, C columnKey,
157            int datasetIndex, double transX, PlotOrientation orientation) {
158
159        Point2D anchor = getAnchor();
160        if (anchor != null) {
161            double anchorX = anchor.getX();
162            if (orientation == PlotOrientation.HORIZONTAL) {
163                anchorX = anchor.getY();
164            }
165            double d = Math.abs(transX - anchorX);
166            if (d < getCrosshairDistance()) {
167                this.rowKey = rowKey;
168                this.columnKey = columnKey;
169                setDatasetIndex(datasetIndex);
170                setCrosshairDistance(d);
171            }
172        }
173
174    }
175
176}