jfreechart example source code file (CategoryStepRenderer.java)

This example jfreechart source code file (CategoryStepRenderer.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, categorydataset, categoryitemrendererstate, categoryplot, categorysteprenderer, categorysteprenderer, geometry, io, legenditem, legenditem, number, paint, stagger_width, state, state, string, string

The jfreechart CategoryStepRenderer.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.]
 *
 * -------------------------
 * CategoryStepRenderer.java
 * -------------------------
 *
 * (C) Copyright 2004-2008, by Brian Cole and Contributors.
 *
 * Original Author:  Brian Cole;
 * Contributor(s):   David Gilbert (for Object Refinery Limited);
 *
 * Changes
 * -------
 * 21-Apr-2004 : Version 1, contributed by Brian Cole (DG);
 * 22-Apr-2004 : Fixed Checkstyle complaints (DG);
 * 05-Nov-2004 : Modified drawItem() signature (DG);
 * 08-Mar-2005 : Added equals() method (DG);
 * ------------- JFREECHART 1.0.x ---------------------------------------------
 * 30-Nov-2006 : Added checks for series visibility (DG);
 * 22-Feb-2007 : Use new state object for reusable line, enable chart entities
 *               (for tooltips, URLs), added new getLegendItem() override (DG);
 * 20-Apr-2007 : Updated getLegendItem() for renderer change (DG);
 * 18-May-2007 : Set dataset and seriesKey for LegendItem (DG);
 * 17-Jun-2008 : Apply legend shape, font and paint attributes (DG);
 *
 */

package org.jfree.chart.renderer.category;

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

import org.jfree.chart.LegendItem;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.EntityCollection;
import org.jfree.chart.event.RendererChangeEvent;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.PlotRenderingInfo;
import org.jfree.chart.renderer.xy.XYStepRenderer;
import org.jfree.data.category.CategoryDataset;
import org.jfree.util.PublicCloneable;

/**
 * A "step" renderer similar to {@link XYStepRenderer} but
 * that can be used with the {@link CategoryPlot} class.  The example shown
 * here is generated by the <code>CategoryStepChartDemo1.java program
 * included in the JFreeChart Demo Collection:
 * <br>

 * <img src="../../../../../images/CategoryStepRendererSample.png"
 * alt="CategoryStepRendererSample.png" />
 */
public class CategoryStepRenderer extends AbstractCategoryItemRenderer
        implements Cloneable, PublicCloneable, Serializable {

    /**
     * State information for the renderer.
     */
    protected static class State extends CategoryItemRendererState {

        /**
         * A working line for re-use to avoid creating large numbers of
         * objects.
         */
        public Line2D line;

        /**
         * Creates a new state instance.
         *
         * @param info  collects plot rendering information (<code>null
         *              permitted).
         */
        public State(PlotRenderingInfo info) {
            super(info);
            this.line = new Line2D.Double();
        }

    }

    /** For serialization. */
    private static final long serialVersionUID = -5121079703118261470L;

    /** The stagger width. */
    public static final int STAGGER_WIDTH = 5; // could make this configurable

    /**
     * A flag that controls whether or not the steps for multiple series are
     * staggered.
     */
    private boolean stagger = false;

    /**
     * Creates a new renderer (stagger defaults to <code>false).
     */
    public CategoryStepRenderer() {
        this(false);
    }

    /**
     * Creates a new renderer.
     *
     * @param stagger  should the horizontal part of the step be staggered by
     *                 series?
     */
    public CategoryStepRenderer(boolean stagger) {
        this.stagger = stagger;
        setBaseLegendShape(new Rectangle2D.Double(-4.0, -3.0, 8.0, 6.0));
    }

    /**
     * Returns the flag that controls whether the series steps are staggered.
     *
     * @return A boolean.
     */
    public boolean getStagger() {
        return this.stagger;
    }

    /**
     * Sets the flag that controls whether or not the series steps are
     * staggered and sends a {@link RendererChangeEvent} to all registered
     * listeners.
     *
     * @param shouldStagger  a boolean.
     */
    public void setStagger(boolean shouldStagger) {
        this.stagger = shouldStagger;
        fireChangeEvent();
    }

    /**
     * Returns a legend item for a series.
     *
     * @param datasetIndex  the dataset index (zero-based).
     * @param series  the series index (zero-based).
     *
     * @return The legend item.
     */
    public LegendItem getLegendItem(int datasetIndex, int series) {

        CategoryPlot p = getPlot();
        if (p == null) {
            return null;
        }

        // check that a legend item needs to be displayed...
        if (!isSeriesVisible(series) || !isSeriesVisibleInLegend(series)) {
            return null;
        }

        CategoryDataset dataset = p.getDataset(datasetIndex);
        String label = getLegendItemLabelGenerator().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);
        }
        Shape shape = lookupLegendShape(series);
        Paint paint = lookupSeriesPaint(series);

        LegendItem item = new LegendItem(label, description, toolTipText,
                urlText, shape, paint);
        item.setLabelFont(lookupLegendTextFont(series));
        Paint labelPaint = lookupLegendTextPaint(series);
        if (labelPaint != null) {
            item.setLabelPaint(labelPaint);
        }
        item.setSeriesKey(dataset.getRowKey(series));
        item.setSeriesIndex(series);
        item.setDataset(dataset);
        item.setDatasetIndex(datasetIndex);
        return item;
    }

    /**
     * Creates a new state instance.  This method is called from
     * {@link #initialise(Graphics2D, Rectangle2D, CategoryPlot, int,
     * PlotRenderingInfo)}, and we override it to ensure that the state
     * contains a working Line2D instance.
     *
     * @param info  the plot rendering info (<code>null is permitted).
     *
     * @return A new state instance.
     */
    protected CategoryItemRendererState createState(PlotRenderingInfo info) {
        return new State(info);
    }

    /**
     * Draws a line taking into account the specified orientation.
     * <p>
     * In version 1.0.5, the signature of this method was changed by the
     * addition of the 'state' parameter.  This is an incompatible change, but
     * is considered a low risk because it is unlikely that anyone has
     * subclassed this renderer.  If this *does* cause trouble for you, please
     * report it as a bug.
     *
     * @param g2  the graphics device.
     * @param state  the renderer state.
     * @param orientation  the plot orientation.
     * @param x0  the x-coordinate for the start of the line.
     * @param y0  the y-coordinate for the start of the line.
     * @param x1  the x-coordinate for the end of the line.
     * @param y1  the y-coordinate for the end of the line.
     */
    protected void drawLine(Graphics2D g2, State state,
            PlotOrientation orientation, double x0, double y0, double x1,
            double y1) {

        if (orientation == PlotOrientation.VERTICAL) {
            state.line.setLine(x0, y0, x1, y1);
            g2.draw(state.line);
        }
        else if (orientation == PlotOrientation.HORIZONTAL) {
            state.line.setLine(y0, x0, y1, x1); // switch x and y
            g2.draw(state.line);
        }

    }

    /**
     * Draw a single data item.
     *
     * @param g2  the graphics device.
     * @param state  the renderer state.
     * @param dataArea  the area in which the data is drawn.
     * @param plot  the plot.
     * @param domainAxis  the domain axis.
     * @param rangeAxis  the range axis.
     * @param dataset  the dataset.
     * @param row  the row index (zero-based).
     * @param column  the column index (zero-based).
     * @param pass  the pass index.
     */
    public void drawItem(Graphics2D g2,
                         CategoryItemRendererState state,
                         Rectangle2D dataArea,
                         CategoryPlot plot,
                         CategoryAxis domainAxis,
                         ValueAxis rangeAxis,
                         CategoryDataset dataset,
                         int row,
                         int column,
                         int pass) {

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

        Number value = dataset.getValue(row, column);
        if (value == null) {
            return;
        }
        PlotOrientation orientation = plot.getOrientation();

        // current data point...
        double x1s = domainAxis.getCategoryStart(column, getColumnCount(),
                dataArea, plot.getDomainAxisEdge());
        double x1 = domainAxis.getCategoryMiddle(column, getColumnCount(),
                dataArea, plot.getDomainAxisEdge());
        double x1e = 2 * x1 - x1s; // or: x1s + 2*(x1-x1s)
        double y1 = rangeAxis.valueToJava2D(value.doubleValue(), dataArea,
                plot.getRangeAxisEdge());
        g2.setPaint(getItemPaint(row, column));
        g2.setStroke(getItemStroke(row, column));

        if (column != 0) {
            Number previousValue = dataset.getValue(row, column - 1);
            if (previousValue != null) {
                // previous data point...
                double previous = previousValue.doubleValue();
                double x0s = domainAxis.getCategoryStart(column - 1,
                        getColumnCount(), dataArea, plot.getDomainAxisEdge());
                double x0 = domainAxis.getCategoryMiddle(column - 1,
                        getColumnCount(), dataArea, plot.getDomainAxisEdge());
                double x0e = 2 * x0 - x0s; // or: x0s + 2*(x0-x0s)
                double y0 = rangeAxis.valueToJava2D(previous, dataArea,
                        plot.getRangeAxisEdge());
                if (getStagger()) {
                    int xStagger = row * STAGGER_WIDTH;
                    if (xStagger > (x1s - x0e)) {
                        xStagger = (int) (x1s - x0e);
                    }
                    x1s = x0e + xStagger;
                }
                drawLine(g2, (State) state, orientation, x0e, y0, x1s, y0);
                // extend x0's flat bar

                drawLine(g2, (State) state, orientation, x1s, y0, x1s, y1);
                // upright bar
           }
       }
       drawLine(g2, (State) state, orientation, x1s, y1, x1e, y1);
       // x1's flat bar

       // draw the item labels if there are any...
       if (isItemLabelVisible(row, column)) {
            drawItemLabel(g2, orientation, dataset, row, column, x1, y1,
                    (value.doubleValue() < 0.0));
       }

       // add an item entity, if this information is being collected
       EntityCollection entities = state.getEntityCollection();
       if (entities != null) {
           Rectangle2D hotspot = new Rectangle2D.Double();
           if (orientation == PlotOrientation.VERTICAL) {
               hotspot.setRect(x1s, y1, x1e - x1s, 4.0);
           }
           else {
               hotspot.setRect(y1 - 2.0, x1s, 4.0, x1e - x1s);
           }
           addItemEntity(entities, dataset, row, column, hotspot);
       }

    }

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

}