barrenderer.java

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/* ======================================
 * JFreeChart : a free Java chart library
 * ======================================
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 * Project Lead:  David Gilbert ([e-mail]);
 *
 * (C) Copyright 2000-2003, by Object Refinery Limited and Contributors.
 *
 * 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., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * ----------------
 * BarRenderer.java
 * ----------------
 * (C) Copyright 2002, 2003 by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   Christian W. Zuckschwerdt;
 *
 * $Id: BarRenderer.java,v 1.19 2003/07/30 15:51:58 mungady Exp $
 *
 * Changes
 * -------
 * 14-Mar-2002 : Version 1 (DG);
 * 23-May-2002 : Added tooltip generator to renderer (DG);
 * 29-May-2002 : Moved tooltip generator to abstract super-class (DG);
 * 25-Jun-2002 : Changed constructor to protected and removed redundant code (DG);
 * 26-Jun-2002 : Added axis to initialise method, and record upper and lower clip values (DG);
 * 24-Sep-2002 : Added getLegendItem(...) method (DG);
 * 09-Oct-2002 : Modified constructor to include URL generator (DG);
 * 05-Nov-2002 : Base dataset is now TableDataset not CategoryDataset (DG);
 * 10-Jan-2003 : Moved get/setItemMargin() method up from subclasses (DG);
 * 17-Jan-2003 : Moved plot classes into a separate package (DG);
 * 25-Mar-2003 : Implemented Serializable (DG);
 * 01-May-2003 : Modified clipping to allow for dual axes and datasets (DG);
 * 12-May-2003 : Merged horizontal and vertical bar renderers (DG);
 * 12-Jun-2003 : Updates for item labels (DG);
 * 30-Jul-2003 : Modified entity constructor (CZ);
 * 
 */

package org.jfree.chart.renderer;

import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Stroke;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.io.Serializable;

import org.jfree.chart.ChartRenderingInfo;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.CategoryItemEntity;
import org.jfree.chart.entity.EntityCollection;
import org.jfree.chart.labels.CategoryItemLabelGenerator;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.CategoryDataset;
import org.jfree.ui.RectangleEdge;
import org.jfree.ui.RefineryUtilities;
import org.jfree.ui.TextAnchor;

/**
 * A {@link CategoryItemRenderer} that represents data using bars.
 *
 * @author David Gilbert
 */
public class BarRenderer extends AbstractCategoryItemRenderer implements Serializable {

    /** The default item margin percentage. */
    public static final double DEFAULT_ITEM_MARGIN = 0.20;

    /** Constant that controls the minimum width before a bar has an outline drawn. */
    public static final double BAR_OUTLINE_WIDTH_THRESHOLD = 3.0;

    /** The margin between items (bars) within a category. */
    private double itemMargin;

    /** A flag that controls whether or not bar outlines are drawn. */
    private boolean drawBarOutline;
    
    /** Temporary storage for the bar width. */
    private double barWidth;

    /** The upper clip (axis) value for the axis. */
    private double upperClip;

    /** The lower clip (axis) value for the axis. */
    private double lowerClip;

    /** The item label anchor offset (used to calculate the anchor point). */
    private double itemLabelAnchorOffset;

    /**
     * Default constructor.
     */
    public BarRenderer() {
        super();
        this.itemMargin = DEFAULT_ITEM_MARGIN;
        this.drawBarOutline = true;
        this.itemLabelAnchorOffset = 2.0;
    }

    /**
     * Returns the item margin.
     *
     * @return the margin.
     */
    public double getItemMargin() {
        return this.itemMargin;
    }

    /**
     * Sets the item margin.  The value is expressed as a percentage of the available width for
     * plotting all the bars, with the resulting amount to be distributed between all the bars
     * evenly.
     *
     * @param percent  the new margin.
     */
    public void setItemMargin(double percent) {
        this.itemMargin = percent;
        firePropertyChanged("ItemMargin", null, null);
    }

    /**
     * Returns a flag that controls whether or not bar outlines are drawn.
     * 
     * @return A boolean.
     */
    public boolean isDrawBarOutline() {
        return this.drawBarOutline;    
    }
    
    /**
     * Sets the flag that controls whether or not bar outlines are drawn.
     * 
     * @param draw  the new flag value.
     */
    public void setDrawBarOutline(boolean draw) {
        this.drawBarOutline = draw;
        firePropertyChanged("DrawBarOutline", null, null);
    }
    
    /**
     * Returns the item label anchor offset.
     *
     * @return The offset.
     */
    public double getItemLabelAnchorOffset() {
        return this.itemLabelAnchorOffset;
    }

    /**
     * Sets the item label anchor offset.
     *
     * @param offset  the offset.
     */
    public void setItemLabelAnchorOffset(double offset) {
        this.itemLabelAnchorOffset = offset;
        firePropertyChanged("ItemLabelAnchorOffset", null, null);
    }

    /**
     * Returns the bar width.
     *
     * @return the bar width.
     */
    public double getBarWidth() {
        return this.barWidth;
    }

    /**
     * Updates the calculated bar width.
     *
     * @param width  the new width.
     */
    protected void setBarWidth(double width) {
        this.barWidth = width;
    }

    /**
     * Returns the lower clip value.
     * <P>
     * This value is recalculated in the initialise() method.
     *
     * @return the value.
     */
    public double getLowerClip() {
        return this.lowerClip;
    }

    /**
     * Returns the upper clip value.
     * <P>
     * This value is recalculated in the initialise() method.
     *
     * @return the value.
     */
    public double getUpperClip() {
        return this.upperClip;
    }

    /**
     * Initialises the renderer.
     * <p>
     * This method gets called once at the start of the process of drawing a chart.
     *
     * @param g2  the graphics device.
     * @param dataArea  the area in which the data is to be plotted.
     * @param plot  the plot.
     * @param info  collects chart rendering information for return to caller.
     *
     */
    public void initialise(Graphics2D g2,
                           Rectangle2D dataArea,
                           CategoryPlot plot,
                           ChartRenderingInfo info) {

        super.initialise(g2, dataArea, plot, info);

        ValueAxis rangeAxis = plot.getRangeAxis();
        this.lowerClip = rangeAxis.getRange().getLowerBound();
        this.upperClip = rangeAxis.getRange().getUpperBound();

        // calculate the bar width
        CategoryAxis domainAxis = plot.getDomainAxis();
        CategoryDataset dataset = plot.getDataset();
        if (dataset != null) {
            int columns = dataset.getColumnCount();
            int rows = dataset.getRowCount();
            double space = 0.0;
            PlotOrientation orientation = plot.getOrientation();
            if (orientation == PlotOrientation.HORIZONTAL) {
                space = dataArea.getHeight();
            }
            else if (orientation == PlotOrientation.VERTICAL) {
                space = dataArea.getWidth();
            }
            double categoryMargin = 0.0;
            double currentItemMargin = 0.0;
            if (columns > 1) {
                categoryMargin = domainAxis.getCategoryMargin();
            }
            if (rows > 1) {
                currentItemMargin = getItemMargin();
            }
            double used = space * (1 - domainAxis.getLowerMargin() - domainAxis.getUpperMargin()
                                     - categoryMargin - currentItemMargin);
            if ((rows * columns) > 0) {
                setBarWidth(used / (dataset.getColumnCount() * dataset.getRowCount()));
            }
            else {
                setBarWidth(used);
            }
        }

    }

    /**
     * Draws the bar for a single (series, category) data item.
     *
     * @param g2  the graphics device.
     * @param dataArea  the data area.
     * @param plot  the plot.
     * @param domainAxis  the domain axis.
     * @param rangeAxis  the range axis.
     * @param data  the data.
     * @param row  the row index (zero-based).
     * @param column  the column index (zero-based).
     */
    public void drawItem(Graphics2D g2,
                         Rectangle2D dataArea,
                         CategoryPlot plot,
                         CategoryAxis domainAxis,
                         ValueAxis rangeAxis,
                         CategoryDataset data,
                         int row,
                         int column) {