levelrenderer.java

jfreechart-1.0.12.zip 可以用来作图

/* ===========================================================
 * 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.]
 *
 * ------------------
 * LevelRenderer.java
 * ------------------
 * (C) Copyright 2004-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 09-Jan-2004 : Version 1 (DG);
 * 05-Nov-2004 : Modified drawItem() signature (DG);
 * 20-Apr-2005 : Renamed CategoryLabelGenerator
 *               --> CategoryItemLabelGenerator (DG);
 * ------------- JFREECHART 1.0.x ---------------------------------------------
 * 23-Jan-2006 : Renamed getMaxItemWidth() --> getMaximumItemWidth() (DG);
 * 13-May-2008 : Code clean-up (DG);
 * 26-Jun-2008 : Added crosshair support (DG);
 *
 */

package org.jfree.chart.renderer.category;

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.axis.CategoryAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.EntityCollection;
import org.jfree.chart.event.RendererChangeEvent;
import org.jfree.chart.labels.CategoryItemLabelGenerator;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.PlotRenderingInfo;
import org.jfree.data.category.CategoryDataset;
import org.jfree.ui.RectangleEdge;
import org.jfree.util.PublicCloneable;

/**
 * A {@link CategoryItemRenderer} that draws individual data items as
 * horizontal lines, spaced in the same way as bars in a bar chart.  The
 * example shown here is generated by the
 * <code>OverlaidBarChartDemo2.java</code> program included in the JFreeChart
 * Demo Collection:
 * <br><br>
 * <img src="../../../../../images/LevelRendererSample.png"
 * alt="LevelRendererSample.png" />
 */
public class LevelRenderer extends AbstractCategoryItemRenderer
        implements Cloneable, PublicCloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -8204856624355025117L;

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

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

    /** The maximum item width as a percentage of the available space. */
    private double maxItemWidth;

    /**
     * Creates a new renderer with default settings.
     */
    public LevelRenderer() {
        super();
        this.itemMargin = DEFAULT_ITEM_MARGIN;
        this.maxItemWidth = 1.0;  // 100 percent, so it will not apply unless
                                  // changed
    }

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

    /**
     * Sets the item margin and sends a {@link RendererChangeEvent} to all
     * registered listeners.  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.
     *
     * @see #getItemMargin()
     */
    public void setItemMargin(double percent) {
        this.itemMargin = percent;
        fireChangeEvent();
    }

    /**
     * Returns the maximum width, as a percentage of the available drawing
     * space.
     *
     * @return The maximum width.
     *
     * @see #setMaximumItemWidth(double)
     */
    public double getMaximumItemWidth() {
        return getMaxItemWidth();
    }

    /**
     * Sets the maximum item width, which is specified as a percentage of the
     * available space for all items, and sends a {@link RendererChangeEvent}
     * to all registered listeners.
     *
     * @param percent  the percent.
     *
     * @see #getMaximumItemWidth()
     */
    public void setMaximumItemWidth(double percent) {
        setMaxItemWidth(percent);
    }

    /**
     * Initialises the renderer and returns a state object that will be passed
     * to subsequent calls to the drawItem method.
     * <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 rendererIndex  the renderer index.
     * @param info  collects chart rendering information for return to caller.
     *
     * @return The renderer state.
     */
    public CategoryItemRendererState initialise(Graphics2D g2,
            Rectangle2D dataArea, CategoryPlot plot, int rendererIndex,
            PlotRenderingInfo info) {

        CategoryItemRendererState state = super.initialise(g2, dataArea, plot,
                rendererIndex, info);
        calculateItemWidth(plot, dataArea, rendererIndex, state);
        return state;

    }

    /**
     * Calculates the bar width and stores it in the renderer state.
     *
     * @param plot  the plot.
     * @param dataArea  the data area.
     * @param rendererIndex  the renderer index.
     * @param state  the renderer state.
     */
    protected void calculateItemWidth(CategoryPlot plot,
            Rectangle2D dataArea, int rendererIndex,
            CategoryItemRendererState state) {

        CategoryAxis domainAxis = getDomainAxis(plot, rendererIndex);
        CategoryDataset dataset = plot.getDataset(rendererIndex);
        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 maxWidth = space * getMaximumItemWidth();
            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) {
                state.setBarWidth(Math.min(used / (rows * columns), maxWidth));
            }
            else {
                state.setBarWidth(Math.min(used, maxWidth));
            }