jfreechart example source code file (VectorRenderer.java)

This example jfreechart source code file (VectorRenderer.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, clonenotsupportedexception, generalpath, generalpath, geometry, illegalargumentexception, io, null, range, range, serializable, valueaxis, vectorrenderer, vectorrenderer, vectorxydataset, vectorxydataset, xydataset

The jfreechart VectorRenderer.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.]
 *
 * -------------------
 * VectorRenderer.java
 * -------------------
 * (C) Copyright 2007, 2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 30-Jan-2007 : Version 1 (DG);
 * 24-May-2007 : Updated for method name changes (DG);
 * 25-May-2007 : Moved from experimental to the main source tree (DG);
 * 18-Feb-2008 : Fixed bug 1880114, arrows for horizontal plot
 *               orientation (DG);
 * 22-Apr-2008 : Implemented PublicCloneable (DG);
 * 26-Sep-2008 : Added chart entity support (tooltips etc) (DG);
 *
 */

package org.jfree.chart.renderer.xy;

import java.awt.Graphics2D;
import java.awt.geom.GeneralPath;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.io.Serializable;

import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.EntityCollection;
import org.jfree.chart.plot.CrosshairState;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.PlotRenderingInfo;
import org.jfree.chart.plot.XYPlot;
import org.jfree.data.Range;
import org.jfree.data.xy.VectorXYDataset;
import org.jfree.data.xy.XYDataset;
import org.jfree.util.PublicCloneable;

/**
 * A renderer that represents data from an {@link VectorXYDataset} by drawing a
 * line with an arrow at each (x, y) point.
 * The example shown here is generated by the <code>VectorPlotDemo1.java
 * program included in the JFreeChart demo collection:
 * <br>

 * <img src="../../../../../images/VectorRendererSample.png"
 * alt="VectorRendererSample.png" />
 *
 * @since 1.0.6
 */
public class VectorRenderer extends AbstractXYItemRenderer
        implements XYItemRenderer, Cloneable, PublicCloneable, Serializable {

    /** The length of the base. */
    private double baseLength = 0.10;

    /** The length of the head. */
    private double headLength = 0.14;

    /**
     * Creates a new <code>XYBlockRenderer instance with default
     * attributes.
     */
    public VectorRenderer() {
    }

    /**
     * Returns the lower and upper bounds (range) of the x-values in the
     * specified dataset.
     *
     * @param dataset  the dataset (<code>null permitted).
     *
     * @return The range (<code>null if the dataset is null
     *         or empty).
     */
    public Range findDomainBounds(XYDataset dataset) {
        if (dataset == null) {
            throw new IllegalArgumentException("Null 'dataset' argument.");
        }
        double minimum = Double.POSITIVE_INFINITY;
        double maximum = Double.NEGATIVE_INFINITY;
        int seriesCount = dataset.getSeriesCount();
        double lvalue;
        double uvalue;
        if (dataset instanceof VectorXYDataset) {
            VectorXYDataset vdataset = (VectorXYDataset) dataset;
            for (int series = 0; series < seriesCount; series++) {
                int itemCount = dataset.getItemCount(series);
                for (int item = 0; item < itemCount; item++) {
                    double delta = vdataset.getVectorXValue(series, item);
                    if (delta < 0.0) {
                        uvalue = vdataset.getXValue(series, item);
                        lvalue = uvalue + delta;
                    }
                    else {
                        lvalue = vdataset.getXValue(series, item);
                        uvalue = lvalue + delta;
                    }
                    minimum = Math.min(minimum, lvalue);
                    maximum = Math.max(maximum, uvalue);
                }
            }
        }
        else {
            for (int series = 0; series < seriesCount; series++) {
                int itemCount = dataset.getItemCount(series);
                for (int item = 0; item < itemCount; item++) {
                    lvalue = dataset.getXValue(series, item);
                    uvalue = lvalue;
                    minimum = Math.min(minimum, lvalue);
                    maximum = Math.max(maximum, uvalue);
                }
            }
        }
        if (minimum > maximum) {
            return null;
        }
        else {
            return new Range(minimum, maximum);
        }
    }

    /**
     * Returns the range of values the renderer requires to display all the
     * items from the specified dataset.
     *
     * @param dataset  the dataset (<code>null permitted).
     *
     * @return The range (<code>null if the dataset is null
     *         or empty).
     */
    public Range findRangeBounds(XYDataset dataset) {
        if (dataset == null) {
            throw new IllegalArgumentException("Null 'dataset' argument.");
        }
        double minimum = Double.POSITIVE_INFINITY;
        double maximum = Double.NEGATIVE_INFINITY;
        int seriesCount = dataset.getSeriesCount();
        double lvalue;
        double uvalue;
        if (dataset instanceof VectorXYDataset) {
            VectorXYDataset vdataset = (VectorXYDataset) dataset;
            for (int series = 0; series < seriesCount; series++) {
                int itemCount = dataset.getItemCount(series);
                for (int item = 0; item < itemCount; item++) {
                    double delta = vdataset.getVectorYValue(series, item);
                    if (delta < 0.0) {
                        uvalue = vdataset.getYValue(series, item);
                        lvalue = uvalue + delta;
                    }
                    else {
                        lvalue = vdataset.getYValue(series, item);
                        uvalue = lvalue + delta;
                    }
                    minimum = Math.min(minimum, lvalue);
                    maximum = Math.max(maximum, uvalue);
                }
            }
        }
        else {
            for (int series = 0; series < seriesCount; series++) {
                int itemCount = dataset.getItemCount(series);
                for (int item = 0; item < itemCount; item++) {
                    lvalue = dataset.getYValue(series, item);
                    uvalue = lvalue;
                    minimum = Math.min(minimum, lvalue);
                    maximum = Math.max(maximum, uvalue);
                }
            }
        }
        if (minimum > maximum) {
            return null;
        }
        else {
            return new Range(minimum, maximum);
        }
    }

    /**
     * Draws the block representing the specified item.
     *
     * @param g2  the graphics device.
     * @param state  the state.
     * @param dataArea  the data area.
     * @param info  the plot rendering info.
     * @param plot  the plot.
     * @param domainAxis  the x-axis.
     * @param rangeAxis  the y-axis.
     * @param dataset  the dataset.
     * @param series  the series index.
     * @param item  the item index.
     * @param crosshairState  the crosshair state.
     * @param pass  the pass index.
     */
    public void drawItem(Graphics2D g2, XYItemRendererState state,
            Rectangle2D dataArea, PlotRenderingInfo info, XYPlot plot,
            ValueAxis domainAxis, ValueAxis rangeAxis, XYDataset dataset,
            int series, int item, CrosshairState crosshairState, int pass) {

        double x = dataset.getXValue(series, item);
        double y = dataset.getYValue(series, item);
        double dx = 0.0;
        double dy = 0.0;
        if (dataset instanceof VectorXYDataset) {
            dx = ((VectorXYDataset) dataset).getVectorXValue(series, item);
            dy = ((VectorXYDataset) dataset).getVectorYValue(series, item);
        }
        double xx0 = domainAxis.valueToJava2D(x, dataArea,
                plot.getDomainAxisEdge());
        double yy0 = rangeAxis.valueToJava2D(y, dataArea,
                plot.getRangeAxisEdge());
        double xx1 = domainAxis.valueToJava2D(x + dx, dataArea,
                plot.getDomainAxisEdge());
        double yy1 = rangeAxis.valueToJava2D(y + dy, dataArea,
                plot.getRangeAxisEdge());
        Line2D line;
        PlotOrientation orientation = plot.getOrientation();
        if (orientation.equals(PlotOrientation.HORIZONTAL)) {
            line = new Line2D.Double(yy0, xx0, yy1, xx1);
        }
        else {
            line = new Line2D.Double(xx0, yy0, xx1, yy1);
        }
        g2.setPaint(getItemPaint(series, item));
        g2.setStroke(getItemStroke(series, item));
        g2.draw(line);

        // calculate the arrow head and draw it...
        double dxx = (xx1 - xx0);
        double dyy = (yy1 - yy0);
        double bx = xx0 + (1.0 - this.baseLength) * dxx;
        double by = yy0 + (1.0 - this.baseLength) * dyy;

        double cx = xx0 + (1.0 - this.headLength) * dxx;
        double cy = yy0 + (1.0 - this.headLength) * dyy;

        double angle = 0.0;
        if (dxx != 0.0) {
            angle = Math.PI / 2.0 - Math.atan(dyy / dxx);
        }
        double deltaX = 2.0 * Math.cos(angle);
        double deltaY = 2.0 * Math.sin(angle);

        double leftx = cx + deltaX;
        double lefty = cy - deltaY;
        double rightx = cx - deltaX;
        double righty = cy + deltaY;

        GeneralPath p = new GeneralPath();
        if (orientation == PlotOrientation.VERTICAL) {
            p.moveTo((float) xx1, (float) yy1);
            p.lineTo((float) rightx, (float) righty);
            p.lineTo((float) bx, (float) by);
            p.lineTo((float) leftx, (float) lefty);
        }
        else {  // orientation is HORIZONTAL
            p.moveTo((float) yy1, (float) xx1);
            p.lineTo((float) righty, (float) rightx);
            p.lineTo((float) by, (float) bx);
            p.lineTo((float) lefty, (float) leftx);
        }
        p.closePath();
        g2.draw(p);

        // setup for collecting optional entity info...
        EntityCollection entities = null;
        if (info != null) {
            entities = info.getOwner().getEntityCollection();
            if (entities != null) {
                addEntity(entities, line.getBounds(), dataset, series, item,
                        0.0, 0.0);
            }
        }

    }

    /**
     * Tests this <code>VectorRenderer for equality with an arbitrary
     * object.  This method returns <code>true if and only if:
     * <ul>
     * <li>obj is an instance of VectorRenderer (not
     *     <code>null);
     * <li>obj has the same field values as this
     *     <code>VectorRenderer;
     * </ul>
     *
     * @param obj  the object (<code>null permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof VectorRenderer)) {
            return false;
        }
        VectorRenderer that = (VectorRenderer) obj;
        if (this.baseLength != that.baseLength) {
            return false;
        }
        if (this.headLength != that.headLength) {
            return false;
        }
        return super.equals(obj);
    }

    /**
     * Returns a clone of this renderer.
     *
     * @return A clone of this renderer.
     *
     * @throws CloneNotSupportedException if there is a problem creating the
     *     clone.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }

}