jfreechart example source code file (DeviationRenderer.java)

This example jfreechart source code file (DeviationRenderer.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, deviationrenderer, deviationrenderer, generalpath, generalpath, geometry, intervalxydataset, plotrenderinginfo, rectangle2d, state, state, util, valueaxis, xydataset, xyitemrendererstate, xyplot, xyplot

The jfreechart DeviationRenderer.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.]
 *
 * ----------------------
 * DeviationRenderer.java
 * ----------------------
 * (C) Copyright 2007-2009, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 21-Feb-2007 : Version 1 (DG);
 * 04-May-2007 : Set processVisibleItemsOnly flag to false (DG);
 * 11-Apr-2008 : New override for findRangeBounds() (DG);
 * 27-Mar-2009 : Updated findRangeBounds() to call new inherited method (DG);
 * 
 */

package org.jfree.chart.renderer.xy;

import java.awt.AlphaComposite;
import java.awt.Composite;
import java.awt.Graphics2D;
import java.awt.geom.GeneralPath;
import java.awt.geom.Rectangle2D;
import java.util.List;

import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.EntityCollection;
import org.jfree.chart.event.RendererChangeEvent;
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.general.DatasetUtilities;
import org.jfree.data.xy.IntervalXYDataset;
import org.jfree.data.xy.XYDataset;
import org.jfree.ui.RectangleEdge;

/**
 * A specialised subclass of the {@link XYLineAndShapeRenderer} that requires
 * an {@link IntervalXYDataset} and represents the y-interval by shading an
 * area behind the y-values on the chart.
 * The example shown here is generated by the
 * <code>DeviationRendererDemo1.java program included in the
 * JFreeChart demo collection:
 * <br>

 * <img src="../../../../../images/DeviationRendererSample.png"
 * alt="DeviationRendererSample.png" />
 *
 * @since 1.0.5
 */
public class DeviationRenderer extends XYLineAndShapeRenderer {

    /**
     * A state object that is passed to each call to <code>drawItem.
     */
    public static class State extends XYLineAndShapeRenderer.State {

        /**
         * A list of coordinates for the upper y-values in the current series
         * (after translation into Java2D space).
         */
        public List upperCoordinates;

        /**
         * A list of coordinates for the lower y-values in the current series
         * (after translation into Java2D space).
         */
        public List lowerCoordinates;

        /**
         * Creates a new state instance.
         *
         * @param info  the plot rendering info.
         */
        public State(PlotRenderingInfo info) {
            super(info);
            this.lowerCoordinates = new java.util.ArrayList();
            this.upperCoordinates = new java.util.ArrayList();
        }

    }

    /** The alpha transparency for the interval shading. */
    private float alpha;

    /**
     * Creates a new renderer that displays lines and shapes for the data
     * items, as well as the shaded area for the y-interval.
     */
    public DeviationRenderer() {
        this(true, true);
    }

    /**
     * Creates a new renderer.
     *
     * @param lines  show lines between data items?
     * @param shapes  show a shape for each data item?
     */
    public DeviationRenderer(boolean lines, boolean shapes) {
        super(lines, shapes);
        super.setDrawSeriesLineAsPath(true);
        this.alpha = 0.5f;
    }

    /**
     * Returns the alpha transparency for the background shading.
     *
     * @return The alpha transparency.
     *
     * @see #setAlpha(float)
     */
    public float getAlpha() {
        return this.alpha;
    }

    /**
     * Sets the alpha transparency for the background shading, and sends a
     * {@link RendererChangeEvent} to all registered listeners.
     *
     * @param alpha   the alpha (in the range 0.0f to 1.0f).
     *
     * @see #getAlpha()
     */
    public void setAlpha(float alpha) {
        if (alpha < 0.0f || alpha > 1.0f) {
            throw new IllegalArgumentException(
                    "Requires 'alpha' in the range 0.0 to 1.0.");
        }
        this.alpha = alpha;
        fireChangeEvent();
    }

    /**
     * This method is overridden so that this flag cannot be changed---it is
     * set to <code>true for this renderer.
     *
     * @param flag  ignored.
     */
    public void setDrawSeriesLineAsPath(boolean flag) {
        // ignore
    }

    /**
     * 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) {
        return findRangeBounds(dataset, true);
    }

    /**
     * Initialises and returns a state object that can be passed to each
     * invocation of the {@link #drawItem} method.
     *
     * @param g2  the graphics target.
     * @param dataArea  the data area.
     * @param plot  the plot.
     * @param dataset  the dataset.
     * @param info  the plot rendering info.
     *
     * @return A newly initialised state object.
     */
    public XYItemRendererState initialise(Graphics2D g2, Rectangle2D dataArea,
            XYPlot plot, XYDataset dataset, PlotRenderingInfo info) {
        State state = new State(info);
        state.seriesPath = new GeneralPath();
        state.setProcessVisibleItemsOnly(false);
        return state;
    }

    /**
     * Returns the number of passes (through the dataset) used by this
     * renderer.
     *
     * @return <code>3.
     */
    public int getPassCount() {
        return 3;
    }

    /**
     * Returns <code>true if this is the pass where the shapes are
     * drawn.
     *
     * @param pass  the pass index.
     *
     * @return A boolean.
     *
     * @see #isLinePass(int)
     */
    protected boolean isItemPass(int pass) {
        return (pass == 2);
    }

    /**
     * Returns <code>true if this is the pass where the lines are
     * drawn.
     *
     * @param pass  the pass index.
     *
     * @return A boolean.
     *
     * @see #isItemPass(int)
     */
    protected boolean isLinePass(int pass) {
        return (pass == 1);
    }

    /**
     * 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 range 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;
        }

        // first pass draws the shading
        if (pass == 0) {
            IntervalXYDataset intervalDataset = (IntervalXYDataset) dataset;
            State drState = (State) state;

            double x = intervalDataset.getXValue(series, item);
            double yLow = intervalDataset.getStartYValue(series, item);
            double yHigh  = intervalDataset.getEndYValue(series, item);

            RectangleEdge xAxisLocation = plot.getDomainAxisEdge();
            RectangleEdge yAxisLocation = plot.getRangeAxisEdge();

            double xx = domainAxis.valueToJava2D(x, dataArea, xAxisLocation);
            double yyLow = rangeAxis.valueToJava2D(yLow, dataArea,
                    yAxisLocation);
            double yyHigh = rangeAxis.valueToJava2D(yHigh, dataArea,
                    yAxisLocation);

            PlotOrientation orientation = plot.getOrientation();
            if (orientation == PlotOrientation.HORIZONTAL) {
                drState.lowerCoordinates.add(new double[] {yyLow, xx});
                drState.upperCoordinates.add(new double[] {yyHigh, xx});
            }
            else if (orientation == PlotOrientation.VERTICAL) {
                drState.lowerCoordinates.add(new double[] {xx, yyLow});
                drState.upperCoordinates.add(new double[] {xx, yyHigh});
            }

            if (item == (dataset.getItemCount(series) - 1)) {
                // last item in series, draw the lot...
                // set up the alpha-transparency...
                Composite originalComposite = g2.getComposite();
                g2.setComposite(AlphaComposite.getInstance(
                        AlphaComposite.SRC_OVER, this.alpha));
                g2.setPaint(getItemFillPaint(series, item));
                GeneralPath area = new GeneralPath();
                double[] coords = (double[]) drState.lowerCoordinates.get(0);
                area.moveTo((float) coords[0], (float) coords[1]);
                for (int i = 1; i < drState.lowerCoordinates.size(); i++) {
                    coords = (double[]) drState.lowerCoordinates.get(i);
                    area.lineTo((float) coords[0], (float) coords[1]);
                }
                int count = drState.upperCoordinates.size();
                coords = (double[]) drState.upperCoordinates.get(count - 1);
                area.lineTo((float) coords[0], (float) coords[1]);
                for (int i = count - 2; i >= 0; i--) {
                    coords = (double[]) drState.upperCoordinates.get(i);
                    area.lineTo((float) coords[0], (float) coords[1]);
                }
                area.closePath();
                g2.fill(area);
                g2.setComposite(originalComposite);

                drState.lowerCoordinates.clear();
                drState.upperCoordinates.clear();
            }
        }
        if (isLinePass(pass)) {

            // the following code handles the line for the y-values...it's
            // all done by code in the super class
            if (item == 0) {
                State s = (State) state;
                s.seriesPath.reset();
                s.setLastPointGood(false);
            }

            if (getItemLineVisible(series, item)) {
                drawPrimaryLineAsPath(state, g2, plot, dataset, pass,
                        series, item, domainAxis, rangeAxis, dataArea);
            }
        }

        // second pass adds shapes where the items are ..
        else if (isItemPass(pass)) {

            // setup for collecting optional entity info...
            EntityCollection entities = null;
            if (info != null) {
                entities = info.getOwner().getEntityCollection();
            }

            drawSecondaryPass(g2, plot, dataset, pass, series, item,
                    domainAxis, dataArea, rangeAxis, crosshairState, entities);
        }
    }

    /**
     * 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 DeviationRenderer)) {
            return false;
        }
        DeviationRenderer that = (DeviationRenderer) obj;
        if (this.alpha != that.alpha) {
            return false;
        }
        return super.equals(obj);
    }

}