jfreechart example source code file (XYStepRenderer.java)

This example jfreechart source code file (XYStepRenderer.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, entitycollection, geometry, io, publiccloneable, rectangleedge, rectangleedge, serializable, valueaxis, valueaxis, xydataset, xyitemrendererstate, xylineandshaperenderer, xylineandshaperenderer, xysteprenderer, xysteprenderer

The jfreechart XYStepRenderer.java source code

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2009, 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.]
 *
 * -------------------
 * XYStepRenderer.java
 * -------------------
 * (C) Copyright 2002-2009, by Roger Studner and Contributors.
 *
 * Original Author:  Roger Studner;
 * Contributor(s):   David Gilbert (for Object Refinery Limited);
 *                   Matthias Rose;
 *                   Gerald Struck (fix for bug 1569094);
 *                   Ulrich Voigt (patch 1874890);
 *                   Martin Hoeller (contribution to patch 1874890);
 *
 * Changes
 * -------
 * 13-May-2002 : Version 1, contributed by Roger Studner (DG);
 * 25-Jun-2002 : Updated import statements (DG);
 * 22-Jul-2002 : Added check for null data items (DG);
 * 25-Mar-2003 : Implemented Serializable (DG);
 * 01-May-2003 : Modified drawItem() method signature (DG);
 * 20-Aug-2003 : Implemented Cloneable and PublicCloneable (DG);
 * 16-Sep-2003 : Changed ChartRenderingInfo --> PlotRenderingInfo (DG);
 * 28-Oct-2003 : Added tooltips, code contributed by Matthias Rose
 *               (RFE 824857) (DG);
 * 10-Feb-2004 : Removed working line (use line from state object instead) (DG);
 * 25-Feb-2004 : Replaced CrosshairInfo with CrosshairState.  Renamed
 *               XYToolTipGenerator --> XYItemLabelGenerator (DG);
 * 19-Jan-2005 : Now accesses only primitives from dataset (DG);
 * 15-Mar-2005 : Fix silly bug in drawItem() method (DG);
 * 19-Sep-2005 : Extend XYLineAndShapeRenderer (fixes legend shapes), added
 *               support for series visibility, and use getDefaultEntityRadius()
 *               for entity hotspot size (DG);
 * ------------- JFREECHART 1.0.x ---------------------------------------------
 * 15-Jun-2006 : Added basic support for item labels (DG);
 * 11-Oct-2006 : Fixed rendering with horizontal orientation (see bug 1569094),
 *               thanks to Gerald Struck (DG);
 * 06-Feb-2007 : Fixed bug 1086307, crosshairs with multiple axes (DG);
 * 14-Feb-2008 : Applied patch 1874890 by Ulrich Voigt (with contribution from
 *               Martin Hoeller) (DG);
 * 14-May-2008 : Call addEntity() in drawItem() (DG);
 * 24-Sep-2008 : Fixed bug 2113627 by utilising second pass to draw item
 *               labels (DG);
 *
 */

package org.jfree.chart.renderer.xy;

import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Stroke;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.io.Serializable;

import org.jfree.chart.HashUtilities;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.EntityCollection;
import org.jfree.chart.event.RendererChangeEvent;
import org.jfree.chart.labels.XYToolTipGenerator;
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.chart.urls.XYURLGenerator;
import org.jfree.data.xy.XYDataset;
import org.jfree.ui.RectangleEdge;
import org.jfree.util.PublicCloneable;

/**
 * Line/Step item renderer for an {@link XYPlot}.  This class draws lines
 * between data points, only allowing horizontal or vertical lines (steps).
 * The example shown here is generated by the
 * <code>XYStepRendererDemo1.java program included in the JFreeChart
 * demo collection:
 * <br>

 * <img src="../../../../../images/XYStepRendererSample.png"
 * alt="XYStepRendererSample.png" />
 */
public class XYStepRenderer extends XYLineAndShapeRenderer
        implements XYItemRenderer, Cloneable, PublicCloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -8918141928884796108L;

    /**
     * The factor (from 0.0 to 1.0) that determines the position of the
     * step.
     *
     * @since 1.0.10.
     */
    private double stepPoint = 1.0d;

    /**
     * Constructs a new renderer with no tooltip or URL generation.
     */
    public XYStepRenderer() {
        this(null, null);
    }

    /**
     * Constructs a new renderer with the specified tool tip and URL
     * generators.
     *
     * @param toolTipGenerator  the item label generator (<code>null
     *     permitted).
     * @param urlGenerator  the URL generator (<code>null permitted).
     */
    public XYStepRenderer(XYToolTipGenerator toolTipGenerator,
                          XYURLGenerator urlGenerator) {
        super();
        setBaseToolTipGenerator(toolTipGenerator);
        setURLGenerator(urlGenerator);
        setBaseShapesVisible(false);
    }

    /**
     * Returns the fraction of the domain position between two points on which
     * the step is drawn.  The default is 1.0d, which means the step is drawn
     * at the domain position of the second`point. If the stepPoint is 0.5d the
     * step is drawn at half between the two points.
     *
     * @return The fraction of the domain position between two points where the
     *         step is drawn.
     *
     * @see #setStepPoint(double)
     *
     * @since 1.0.10
     */
    public double getStepPoint() {
        return this.stepPoint;
    }

    /**
     * Sets the step point and sends a {@link RendererChangeEvent} to all
     * registered listeners.
     *
     * @param stepPoint  the step point (in the range 0.0 to 1.0)
     *
     * @see #getStepPoint()
     *
     * @since 1.0.10
     */
    public void setStepPoint(double stepPoint) {
        if (stepPoint < 0.0d || stepPoint > 1.0d) {
            throw new IllegalArgumentException(
                    "Requires stepPoint in [0.0;1.0]");
        }
        this.stepPoint = stepPoint;
        fireChangeEvent();
    }

    /**
     * Draws the visual representation of a single data item.
     *
     * @param g2  the graphics device.
     * @param state  the renderer state.
     * @param dataArea  the area within which the data is being drawn.
     * @param info  collects information about the drawing.
     * @param plot  the plot (can be used to obtain standard color
     *              information etc).
     * @param domainAxis  the domain axis.
     * @param rangeAxis  the vertical axis.
     * @param dataset  the dataset.
     * @param series  the series index (zero-based).
     * @param item  the item index (zero-based).
     * @param crosshairState  crosshair information for the plot
     *                        (<code>null permitted).
     * @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) {

        // do nothing if item is not visible
        if (!getItemVisible(series, item)) {
            return;
        }

        PlotOrientation orientation = plot.getOrientation();

        Paint seriesPaint = getItemPaint(series, item);
        Stroke seriesStroke = getItemStroke(series, item);
        g2.setPaint(seriesPaint);
        g2.setStroke(seriesStroke);

        // get the data point...
        double x1 = dataset.getXValue(series, item);
        double y1 = dataset.getYValue(series, item);

        RectangleEdge xAxisLocation = plot.getDomainAxisEdge();
        RectangleEdge yAxisLocation = plot.getRangeAxisEdge();
        double transX1 = domainAxis.valueToJava2D(x1, dataArea, xAxisLocation);
        double transY1 = (Double.isNaN(y1) ? Double.NaN
                : rangeAxis.valueToJava2D(y1, dataArea, yAxisLocation));

        if (pass == 0 && item > 0) {
            // get the previous data point...
            double x0 = dataset.getXValue(series, item - 1);
            double y0 = dataset.getYValue(series, item - 1);
            double transX0 = domainAxis.valueToJava2D(x0, dataArea,
                    xAxisLocation);
            double transY0 = (Double.isNaN(y0) ? Double.NaN
                    : rangeAxis.valueToJava2D(y0, dataArea, yAxisLocation));

            if (orientation == PlotOrientation.HORIZONTAL) {
                if (transY0 == transY1) {
                    // this represents the situation
                    // for drawing a horizontal bar.
                    drawLine(g2, state.workingLine, transY0, transX0, transY1,
                            transX1);
                }
                else {  //this handles the need to perform a 'step'.

                    // calculate the step point
                    double transXs = transX0 + (getStepPoint()
                            * (transX1 - transX0));
                    drawLine(g2, state.workingLine, transY0, transX0, transY0,
                            transXs);
                    drawLine(g2, state.workingLine, transY0, transXs, transY1,
                            transXs);
                    drawLine(g2, state.workingLine, transY1, transXs, transY1,
                            transX1);
                }
            }
            else if (orientation == PlotOrientation.VERTICAL) {
                if (transY0 == transY1) { // this represents the situation
                                          // for drawing a horizontal bar.
                    drawLine(g2, state.workingLine, transX0, transY0, transX1,
                            transY1);
                }
                else {  //this handles the need to perform a 'step'.
                    // calculate the step point
                    double transXs = transX0 + (getStepPoint()
                            * (transX1 - transX0));
                    drawLine(g2, state.workingLine, transX0, transY0, transXs,
                            transY0);
                    drawLine(g2, state.workingLine, transXs, transY0, transXs,
                            transY1);
                    drawLine(g2, state.workingLine, transXs, transY1, transX1,
                            transY1);
                }
            }

            // submit this data item as a candidate for the crosshair point
            int domainAxisIndex = plot.getDomainAxisIndex(domainAxis);
            int rangeAxisIndex = plot.getRangeAxisIndex(rangeAxis);
            updateCrosshairValues(crosshairState, x1, y1, domainAxisIndex,
                    rangeAxisIndex, transX1, transY1, orientation);

            // collect entity and tool tip information...
            EntityCollection entities = state.getEntityCollection();
            if (entities != null) {
                addEntity(entities, null, dataset, series, item, transX1,
                        transY1);
            }

        }

        if (pass == 1) {
            // draw the item label if there is one...
            if (isItemLabelVisible(series, item)) {
                double xx = transX1;
                double yy = transY1;
                if (orientation == PlotOrientation.HORIZONTAL) {
                    xx = transY1;
                    yy = transX1;
                }
                drawItemLabel(g2, orientation, dataset, series, item, xx, yy,
                        (y1 < 0.0));
            }
        }
    }

    /**
     * A utility method that draws a line but only if none of the coordinates
     * are NaN values.
     *
     * @param g2  the graphics target.
     * @param line  the line object.
     * @param x0  the x-coordinate for the starting point of the line.
     * @param y0  the y-coordinate for the starting point of the line.
     * @param x1  the x-coordinate for the ending point of the line.
     * @param y1  the y-coordinate for the ending point of the line.
     */
    private void drawLine(Graphics2D g2, Line2D line, double x0, double y0,
            double x1, double y1) {
        if (Double.isNaN(x0) || Double.isNaN(x1) || Double.isNaN(y0)
                || Double.isNaN(y1)) {
            return;
        }
        line.setLine(x0, y0, x1, y1);
        g2.draw(line);
    }

    /**
     * Tests this renderer for equality with an arbitrary object.
     *
     * @param obj  the object (<code>null permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof XYLineAndShapeRenderer)) {
            return false;
        }
        XYStepRenderer that = (XYStepRenderer) obj;
        if (this.stepPoint != that.stepPoint) {
            return false;
        }
        return super.equals(obj);
    }

    /**
     * Returns a hash code for this instance.
     *
     * @return A hash code.
     */
    public int hashCode() {
        return HashUtilities.hashCode(super.hashCode(), this.stepPoint);
    }

    /**
     * Returns a clone of the renderer.
     *
     * @return A clone.
     *
     * @throws CloneNotSupportedException  if the renderer cannot be cloned.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }

}