001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, 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-present, 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 extends CrosshairState {
051
052    /**
053     * The row key for the crosshair point.
054     */
055    private Comparable rowKey;
056
057    /**
058     * The column key for the crosshair point.
059     */
060    private Comparable columnKey;
061
062    /**
063     * Creates a new instance.
064     */
065    public CategoryCrosshairState() {
066        this.rowKey = null;
067        this.columnKey = null;
068    }
069
070    /**
071     * Returns the row key.
072     *
073     * @return The row key.
074     */
075    public Comparable getRowKey() {
076        return this.rowKey;
077    }
078
079    /**
080     * Sets the row key.
081     *
082     * @param key  the row key.
083     */
084    public void setRowKey(Comparable key) {
085        this.rowKey = key;
086    }
087
088    /**
089     * Returns the column key.
090     *
091     * @return The column key.
092     */
093    public Comparable getColumnKey() {
094        return this.columnKey;
095    }
096
097    /**
098     * Sets the column key.
099     *
100     * @param key  the key.
101     */
102    public void setColumnKey(Comparable key) {
103        this.columnKey = key;
104    }
105
106    /**
107     * Evaluates a data point from a {@link CategoryItemRenderer} and if it is
108     * the closest to the anchor point it becomes the new crosshair point.
109     *
110     * @param rowKey  the row key.
111     * @param columnKey  the column key.
112     * @param value  y coordinate (measured against the range axis).
113     * @param datasetIndex  the dataset index for this point.
114     * @param transX  x translated into Java2D space.
115     * @param transY  y translated into Java2D space.
116     * @param orientation  the plot orientation.
117     */
118    public void updateCrosshairPoint(Comparable rowKey, Comparable columnKey,
119            double value, int datasetIndex, double transX, double transY,
120            PlotOrientation orientation) {
121
122        Point2D anchor = getAnchor();
123        if (anchor != null) {
124            double xx = anchor.getX();
125            double yy = anchor.getY();
126            if (orientation == PlotOrientation.HORIZONTAL) {
127                double temp = yy;
128                yy = xx;
129                xx = temp;
130            }
131            double d = (transX - xx) * (transX - xx)
132                    + (transY - yy) * (transY - yy);
133
134            if (d < getCrosshairDistance()) {
135                this.rowKey = rowKey;
136                this.columnKey = columnKey;
137                setCrosshairY(value);
138                setDatasetIndex(datasetIndex);
139                setCrosshairDistance(d);
140            }
141        }
142
143    }
144
145    /**
146     * Updates only the crosshair row and column keys (this is for the case
147     * where the range crosshair does NOT lock onto the nearest data value).
148     *
149     * @param rowKey  the row key.
150     * @param columnKey  the column key.
151     * @param datasetIndex  the dataset axis index.
152     * @param transX  the translated x-value.
153     * @param orientation  the plot orientation.
154     */
155    public void updateCrosshairX(Comparable rowKey, Comparable columnKey,
156            int datasetIndex, double transX, PlotOrientation orientation) {
157
158        Point2D anchor = getAnchor();
159        if (anchor != null) {
160            double anchorX = anchor.getX();
161            if (orientation == PlotOrientation.HORIZONTAL) {
162                anchorX = anchor.getY();
163            }
164            double d = Math.abs(transX - anchorX);
165            if (d < getCrosshairDistance()) {
166                this.rowKey = rowKey;
167                this.columnKey = columnKey;
168                setDatasetIndex(datasetIndex);
169                setCrosshairDistance(d);
170            }
171        }
172
173    }
174
175}