jfreechart example source code file (XYAreaRenderer.java)

This example jfreechart source code file (XYAreaRenderer.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

area, area, awt, basicstroke, geometry, io, polygon, polygon, shape, string, xyarearenderer, xyarearenderer, xyarearendererstate, xyarearendererstate, xydataset, xyitemrendererstate, xyplot

The jfreechart XYAreaRenderer.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.]
 *
 * -------------------
 * XYAreaRenderer.java
 * -------------------
 * (C) Copyright 2002-2008, by Hari and Contributors.
 *
 * Original Author:  Hari (ourhari@hotmail.com);
 * Contributor(s):   David Gilbert (for Object Refinery Limited);
 *                   Richard Atkinson;
 *                   Christian W. Zuckschwerdt;
 *
 * Changes:
 * --------
 * 03-Apr-2002 : Version 1, contributed by Hari.  This class is based on the
 *               StandardXYItemRenderer class (DG);
 * 09-Apr-2002 : Removed the translated zero from the drawItem method -
 *               overridden the initialise() method to calculate it (DG);
 * 30-May-2002 : Added tool tip generator to constructor to match super
 *               class (DG);
 * 25-Jun-2002 : Removed unnecessary local variable (DG);
 * 05-Aug-2002 : Small modification to drawItem method to support URLs for HTML
 *               image maps (RA);
 * 01-Oct-2002 : Fixed errors reported by Checkstyle (DG);
 * 07-Nov-2002 : Renamed AreaXYItemRenderer --> XYAreaRenderer (DG);
 * 25-Mar-2003 : Implemented Serializable (DG);
 * 01-May-2003 : Modified drawItem() method signature (DG);
 * 27-Jul-2003 : Made line and polygon properties protected rather than
 *               private (RA);
 * 30-Jul-2003 : Modified entity constructor (CZ);
 * 20-Aug-2003 : Implemented Cloneable and PublicCloneable (DG);
 * 16-Sep-2003 : Changed ChartRenderingInfo --> PlotRenderingInfo (DG);
 * 07-Oct-2003 : Added renderer state (DG);
 * 08-Dec-2003 : Modified hotspot for chart entity (DG);
 * 10-Feb-2004 : Changed the drawItem() method to make cut-and-paste overriding
 *               easier.  Also moved state class into this class (DG);
 * 25-Feb-2004 : Replaced CrosshairInfo with CrosshairState.  Renamed
 *               XYToolTipGenerator --> XYItemLabelGenerator (DG);
 * 15-Jul-2004 : Switched getX() with getXValue() and getY() with
 *               getYValue() (DG);
 * 11-Nov-2004 : Now uses ShapeUtilities to translate shapes (DG);
 * 19-Jan-2005 : Now accesses primitives only from dataset (DG);
 * 21-Mar-2005 : Override getLegendItem() and equals() methods (DG);
 * 20-Apr-2005 : Use generators for legend tooltips and URLs (DG);
 * ------------- JFREECHART 1.0.x ---------------------------------------------
 * 06-Feb-2007 : Fixed bug 1086307, crosshairs with multiple axes (DG);
 * 14-Feb-2007 : Fixed bug in clone() (DG);
 * 20-Apr-2007 : Updated getLegendItem() for renderer change (DG);
 * 04-May-2007 : Set processVisibleItemsOnly flag to false (DG);
 * 17-May-2007 : Set datasetIndex and seriesIndex in getLegendItem() (DG);
 * 18-May-2007 : Set dataset and seriesKey for LegendItem (DG);
 * 17-Jun-2008 : Apply legend font and paint attributes (DG);
 * 31-Dec-2008 : Fix for bug 2471906 - dashed outlines performance issue (DG);
 *
 */

package org.jfree.chart.renderer.xy;

import java.awt.BasicStroke;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Polygon;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.geom.Area;
import java.awt.geom.GeneralPath;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

import org.jfree.chart.LegendItem;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.EntityCollection;
import org.jfree.chart.event.RendererChangeEvent;
import org.jfree.chart.labels.XYSeriesLabelGenerator;
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.io.SerialUtilities;
import org.jfree.util.PublicCloneable;
import org.jfree.util.ShapeUtilities;

/**
 * Area item renderer for an {@link XYPlot}.  This class can draw (a) shapes at
 * each point, or (b) lines between points, or (c) both shapes and lines,
 * or (d) filled areas, or (e) filled areas and shapes. The example shown here
 * is generated by the <code>XYAreaRendererDemo1.java program included
 * in the JFreeChart demo collection:
 * <br>

 * <img src="../../../../../images/XYAreaRendererSample.png"
 * alt="XYAreaRendererSample.png" />
 */
public class XYAreaRenderer extends AbstractXYItemRenderer
        implements XYItemRenderer, PublicCloneable {

    /** For serialization. */
    private static final long serialVersionUID = -4481971353973876747L;

    /**
     * A state object used by this renderer.
     */
    static class XYAreaRendererState extends XYItemRendererState {

        /** Working storage for the area under one series. */
        public Polygon area;

        /** Working line that can be recycled. */
        public Line2D line;

        /**
         * Creates a new state.
         *
         * @param info  the plot rendering info.
         */
        public XYAreaRendererState(PlotRenderingInfo info) {
            super(info);
            this.area = new Polygon();
            this.line = new Line2D.Double();
        }

    }

    /** Useful constant for specifying the type of rendering (shapes only). */
    public static final int SHAPES = 1;

    /** Useful constant for specifying the type of rendering (lines only). */
    public static final int LINES = 2;

    /**
     * Useful constant for specifying the type of rendering (shapes and lines).
     */
    public static final int SHAPES_AND_LINES = 3;

    /** Useful constant for specifying the type of rendering (area only). */
    public static final int AREA = 4;

    /**
     * Useful constant for specifying the type of rendering (area and shapes).
     */
    public static final int AREA_AND_SHAPES = 5;

    /** A flag indicating whether or not shapes are drawn at each XY point. */
    private boolean plotShapes;

    /** A flag indicating whether or not lines are drawn between XY points. */
    private boolean plotLines;

    /** A flag indicating whether or not Area are drawn at each XY point. */
    private boolean plotArea;

    /** A flag that controls whether or not the outline is shown. */
    private boolean showOutline;

    /**
     * The shape used to represent an area in each legend item (this should
     * never be <code>null).
     */
    private transient Shape legendArea;

    /**
     * Constructs a new renderer.
     */
    public XYAreaRenderer() {
        this(AREA);
    }

    /**
     * Constructs a new renderer.
     *
     * @param type  the type of the renderer.
     */
    public XYAreaRenderer(int type) {
        this(type, null, null);
    }

    /**
     * Constructs a new renderer.  To specify the type of renderer, use one of
     * the constants: <code>SHAPES, LINES,
     * <code>SHAPES_AND_LINES, AREA or
     * <code>AREA_AND_SHAPES.
     *
     * @param type  the type of renderer.
     * @param toolTipGenerator  the tool tip generator to use
     *                          (<code>null permitted).
     * @param urlGenerator  the URL generator (<code>null permitted).
     */
    public XYAreaRenderer(int type, XYToolTipGenerator toolTipGenerator,
                          XYURLGenerator urlGenerator) {

        super();
        setBaseToolTipGenerator(toolTipGenerator);
        setURLGenerator(urlGenerator);

        if (type == SHAPES) {
            this.plotShapes = true;
        }
        if (type == LINES) {
            this.plotLines = true;
        }
        if (type == SHAPES_AND_LINES) {
            this.plotShapes = true;
            this.plotLines = true;
        }
        if (type == AREA) {
            this.plotArea = true;
        }
        if (type == AREA_AND_SHAPES) {
            this.plotArea = true;
            this.plotShapes = true;
        }
        this.showOutline = false;
        GeneralPath area = new GeneralPath();
        area.moveTo(0.0f, -4.0f);
        area.lineTo(3.0f, -2.0f);
        area.lineTo(4.0f, 4.0f);
        area.lineTo(-4.0f, 4.0f);
        area.lineTo(-3.0f, -2.0f);
        area.closePath();
        this.legendArea = area;

    }

    /**
     * Returns true if shapes are being plotted by the renderer.
     *
     * @return <code>true if shapes are being plotted by the renderer.
     */
    public boolean getPlotShapes() {
        return this.plotShapes;
    }

    /**
     * Returns true if lines are being plotted by the renderer.
     *
     * @return <code>true if lines are being plotted by the renderer.
     */
    public boolean getPlotLines() {
        return this.plotLines;
    }

    /**
     * Returns true if Area is being plotted by the renderer.
     *
     * @return <code>true if Area is being plotted by the renderer.
     */
    public boolean getPlotArea() {
        return this.plotArea;
    }

    /**
     * Returns a flag that controls whether or not outlines of the areas are
     * drawn.
     *
     * @return The flag.
     *
     * @see #setOutline(boolean)
     */
    public boolean isOutline() {
        return this.showOutline;
    }

    /**
     * Sets a flag that controls whether or not outlines of the areas are drawn
     * and sends a {@link RendererChangeEvent} to all registered listeners.
     *
     * @param show  the flag.
     *
     * @see #isOutline()
     */
    public void setOutline(boolean show) {
        this.showOutline = show;
        fireChangeEvent();
    }

    /**
     * Returns the shape used to represent an area in the legend.
     *
     * @return The legend area (never <code>null).
     */
    public Shape getLegendArea() {
        return this.legendArea;
    }

    /**
     * Sets the shape used as an area in each legend item and sends a
     * {@link RendererChangeEvent} to all registered listeners.
     *
     * @param area  the area (<code>null not permitted).
     */
    public void setLegendArea(Shape area) {
        if (area == null) {
            throw new IllegalArgumentException("Null 'area' argument.");
        }
        this.legendArea = area;
        fireChangeEvent();
    }

    /**
     * Initialises the renderer and returns a state object that should be
     * passed to all subsequent calls to the drawItem() method.
     *
     * @param g2  the graphics device.
     * @param dataArea  the area inside the axes.
     * @param plot  the plot.
     * @param data  the data.
     * @param info  an optional info collection object to return data back to
     *              the caller.
     *
     * @return A state object for use by the renderer.
     */
    public XYItemRendererState initialise(Graphics2D g2, Rectangle2D dataArea,
            XYPlot plot, XYDataset data, PlotRenderingInfo info) {
        XYAreaRendererState state = new XYAreaRendererState(info);

        // in the rendering process, there is special handling for item
        // zero, so we can't support processing of visible data items only
        state.setProcessVisibleItemsOnly(false);
        return state;
    }

    /**
     * Returns a default legend item for the specified series.  Subclasses
     * should override this method to generate customised items.
     *
     * @param datasetIndex  the dataset index (zero-based).
     * @param series  the series index (zero-based).
     *
     * @return A legend item for the series.
     */
    public LegendItem getLegendItem(int datasetIndex, int series) {
        LegendItem result = null;
        XYPlot xyplot = getPlot();
        if (xyplot != null) {
            XYDataset dataset = xyplot.getDataset(datasetIndex);
            if (dataset != null) {
                XYSeriesLabelGenerator lg = getLegendItemLabelGenerator();
                String label = lg.generateLabel(dataset, series);
                String description = label;
                String toolTipText = null;
                if (getLegendItemToolTipGenerator() != null) {
                    toolTipText = getLegendItemToolTipGenerator().generateLabel(
                            dataset, series);
                }
                String urlText = null;
                if (getLegendItemURLGenerator() != null) {
                    urlText = getLegendItemURLGenerator().generateLabel(
                            dataset, series);
                }
                Paint paint = lookupSeriesPaint(series);
                result = new LegendItem(label, description, toolTipText,
                        urlText, this.legendArea, paint);
                result.setLabelFont(lookupLegendTextFont(series));
                Paint labelPaint = lookupLegendTextPaint(series);
                if (labelPaint != null) {
                    result.setLabelPaint(labelPaint);
                }
                result.setDataset(dataset);
                result.setDatasetIndex(datasetIndex);
                result.setSeriesKey(dataset.getSeriesKey(series));
                result.setSeriesIndex(series);
            }
        }
        return result;
    }

    /**
     * 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) {

        if (!getItemVisible(series, item)) {
            return;
        }
        XYAreaRendererState areaState = (XYAreaRendererState) state;

        // get the data point...
        double x1 = dataset.getXValue(series, item);
        double y1 = dataset.getYValue(series, item);
        if (Double.isNaN(y1)) {
            y1 = 0.0;
        }
        double transX1 = domainAxis.valueToJava2D(x1, dataArea,
                plot.getDomainAxisEdge());
        double transY1 = rangeAxis.valueToJava2D(y1, dataArea,
                plot.getRangeAxisEdge());

        // get the previous point and the next point so we can calculate a
        // "hot spot" for the area (used by the chart entity)...
        int itemCount = dataset.getItemCount(series);
        double x0 = dataset.getXValue(series, Math.max(item - 1, 0));
        double y0 = dataset.getYValue(series, Math.max(item - 1, 0));
        if (Double.isNaN(y0)) {
            y0 = 0.0;
        }
        double transX0 = domainAxis.valueToJava2D(x0, dataArea,
                plot.getDomainAxisEdge());
        double transY0 = rangeAxis.valueToJava2D(y0, dataArea,
                plot.getRangeAxisEdge());

        double x2 = dataset.getXValue(series, Math.min(item + 1,
                itemCount - 1));
        double y2 = dataset.getYValue(series, Math.min(item + 1,
                itemCount - 1));
        if (Double.isNaN(y2)) {
            y2 = 0.0;
        }
        double transX2 = domainAxis.valueToJava2D(x2, dataArea,
                plot.getDomainAxisEdge());
        double transY2 = rangeAxis.valueToJava2D(y2, dataArea,
                plot.getRangeAxisEdge());

        double transZero = rangeAxis.valueToJava2D(0.0, dataArea,
                plot.getRangeAxisEdge());
        Polygon hotspot = null;
        if (plot.getOrientation() == PlotOrientation.HORIZONTAL) {
            hotspot = new Polygon();
            hotspot.addPoint((int) transZero,
                    (int) ((transX0 + transX1) / 2.0));
            hotspot.addPoint((int) ((transY0 + transY1) / 2.0),
                    (int) ((transX0 + transX1) / 2.0));
            hotspot.addPoint((int) transY1, (int) transX1);
            hotspot.addPoint((int) ((transY1 + transY2) / 2.0),
                    (int) ((transX1 + transX2) / 2.0));
            hotspot.addPoint((int) transZero,
                    (int) ((transX1 + transX2) / 2.0));
        }
        else {  // vertical orientation
            hotspot = new Polygon();
            hotspot.addPoint((int) ((transX0 + transX1) / 2.0),
                    (int) transZero);
            hotspot.addPoint((int) ((transX0 + transX1) / 2.0),
                    (int) ((transY0 + transY1) / 2.0));
            hotspot.addPoint((int) transX1, (int) transY1);
            hotspot.addPoint((int) ((transX1 + transX2) / 2.0),
                    (int) ((transY1 + transY2) / 2.0));
            hotspot.addPoint((int) ((transX1 + transX2) / 2.0),
                    (int) transZero);
        }

        if (item == 0) {  // create a new area polygon for the series
            areaState.area = new Polygon();
            // the first point is (x, 0)
            double zero = rangeAxis.valueToJava2D(0.0, dataArea,
                    plot.getRangeAxisEdge());
            if (plot.getOrientation() == PlotOrientation.VERTICAL) {
                areaState.area.addPoint((int) transX1, (int) zero);
            }
            else if (plot.getOrientation() == PlotOrientation.HORIZONTAL) {
                areaState.area.addPoint((int) zero, (int) transX1);
            }
        }

        // Add each point to Area (x, y)
        if (plot.getOrientation() == PlotOrientation.VERTICAL) {
            areaState.area.addPoint((int) transX1, (int) transY1);
        }
        else if (plot.getOrientation() == PlotOrientation.HORIZONTAL) {
            areaState.area.addPoint((int) transY1, (int) transX1);
        }

        PlotOrientation orientation = plot.getOrientation();
        Paint paint = getItemPaint(series, item);
        Stroke stroke = getItemStroke(series, item);
        g2.setPaint(paint);
        g2.setStroke(stroke);

        Shape shape = null;
        if (getPlotShapes()) {
            shape = getItemShape(series, item);
            if (orientation == PlotOrientation.VERTICAL) {
                shape = ShapeUtilities.createTranslatedShape(shape, transX1,
                        transY1);
            }
            else if (orientation == PlotOrientation.HORIZONTAL) {
                shape = ShapeUtilities.createTranslatedShape(shape, transY1,
                        transX1);
            }
            g2.draw(shape);
        }

        if (getPlotLines()) {
            if (item > 0) {
                if (plot.getOrientation() == PlotOrientation.VERTICAL) {
                    areaState.line.setLine(transX0, transY0, transX1, transY1);
                }
                else if (plot.getOrientation() == PlotOrientation.HORIZONTAL) {
                    areaState.line.setLine(transY0, transX0, transY1, transX1);
                }
                g2.draw(areaState.line);
            }
        }

        // Check if the item is the last item for the series.
        // and number of items > 0.  We can't draw an area for a single point.
        if (getPlotArea() && item > 0 && item == (itemCount - 1)) {

            if (orientation == PlotOrientation.VERTICAL) {
                // Add the last point (x,0)
                areaState.area.addPoint((int) transX1, (int) transZero);
            }
            else if (orientation == PlotOrientation.HORIZONTAL) {
                // Add the last point (x,0)
                areaState.area.addPoint((int) transZero, (int) transX1);
            }

            g2.fill(areaState.area);

            // draw an outline around the Area.
            if (isOutline()) {
                Shape area = areaState.area;

                // Java2D has some issues drawing dashed lines around "large"
                // geometrical shapes - for example, see bug 6620013 in the
                // Java bug database.  So, we'll check if the outline is
                // dashed and, if it is, do our own clipping before drawing
                // the outline...
                Stroke outlineStroke = lookupSeriesOutlineStroke(series);
                if (outlineStroke instanceof BasicStroke) {
                    BasicStroke bs = (BasicStroke) outlineStroke;
                    if (bs.getDashArray() != null) {
                        Area poly = new Area(areaState.area);
                        // we make the clip region slightly larger than the
                        // dataArea so that the clipped edges don't show lines
                        // on the chart
                        Area clip = new Area(new Rectangle2D.Double(
                                dataArea.getX() - 5.0, dataArea.getY() - 5.0,
                                dataArea.getWidth() + 10.0,
                                dataArea.getHeight() + 10.0));
                        poly.intersect(clip);
                        area = poly;
                    }
                } // end of workaround

                g2.setStroke(outlineStroke);
                g2.setPaint(lookupSeriesOutlinePaint(series));
                g2.draw(area);
            }
        }

        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 && hotspot != null) {
            addEntity(entities, hotspot, dataset, series, item, 0.0, 0.0);
        }

    }

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

    /**
     * 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 XYAreaRenderer)) {
            return false;
        }
        XYAreaRenderer that = (XYAreaRenderer) obj;
        if (this.plotArea != that.plotArea) {
            return false;
        }
        if (this.plotLines != that.plotLines) {
            return false;
        }
        if (this.plotShapes != that.plotShapes) {
            return false;
        }
        if (this.showOutline != that.showOutline) {
            return false;
        }
        if (!ShapeUtilities.equal(this.legendArea, that.legendArea)) {
            return false;
        }
        return true;
    }

    /**
     * Provides serialization support.
     *
     * @param stream  the input stream.
     *
     * @throws IOException  if there is an I/O error.
     * @throws ClassNotFoundException  if there is a classpath problem.
     */
    private void readObject(ObjectInputStream stream)
            throws IOException, ClassNotFoundException {
        stream.defaultReadObject();
        this.legendArea = SerialUtilities.readShape(stream);
    }

    /**
     * Provides serialization support.
     *
     * @param stream  the output stream.
     *
     * @throws IOException  if there is an I/O error.
     */
    private void writeObject(ObjectOutputStream stream) throws IOException {
        stream.defaultWriteObject();
        SerialUtilities.writeShape(this.legendArea, stream);
    }
}