jfreechart example source code file (MarkerAxisBand.java)

This example jfreechart source code file (MarkerAxisBand.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, font, font, fontmetrics, geometry, intervalmarker, intervalmarker, io, iterator, linemetrics, markeraxisband, markeraxisband, numberaxis, rectangle2d, rectangle2d, serializable, string, util

The jfreechart MarkerAxisBand.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.]
 *
 * -------------------
 * MarkerAxisBand.java
 * -------------------
 * (C) Copyright 2000-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 03-Sep-2002 : Updated Javadoc comments (DG);
 * 01-Oct-2002 : Fixed errors reported by Checkstyle (DG);
 * 08-Nov-2002 : Moved to new package com.jrefinery.chart.axis (DG);
 * 26-Mar-2003 : Implemented Serializable (DG);
 * 13-May-2003 : Renamed HorizontalMarkerAxisBand --> MarkerAxisBand (DG);
 * 29-Oct-2003 : Added workaround for font alignment in PDF output (DG);
 * 21-Jan-2004 : Update for renamed method in ValueAxis (DG);
 * 07-Apr-2004 : Changed text bounds calculation (DG);
 *
 */

package org.jfree.chart.axis;

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Composite;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.font.LineMetrics;
import java.awt.geom.Rectangle2D;
import java.io.Serializable;
import java.util.Iterator;
import java.util.List;

import org.jfree.chart.plot.IntervalMarker;
import org.jfree.text.TextUtilities;
import org.jfree.ui.RectangleEdge;
import org.jfree.util.ObjectUtilities;

/**
 * A band that can be added to a number axis to display regions.
 */
public class MarkerAxisBand implements Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -1729482413886398919L;

    /** The axis that the band belongs to. */
    private NumberAxis axis;

    /** The top outer gap. */
    private double topOuterGap;

    /** The top inner gap. */
    private double topInnerGap;

    /** The bottom outer gap. */
    private double bottomOuterGap;

    /** The bottom inner gap. */
    private double bottomInnerGap;

    /** The font. */
    private Font font;

    /** Storage for the markers. */
    private List markers;

    /**
     * Constructs a new axis band.
     *
     * @param axis  the owner.
     * @param topOuterGap  the top outer gap.
     * @param topInnerGap  the top inner gap.
     * @param bottomOuterGap  the bottom outer gap.
     * @param bottomInnerGap  the bottom inner gap.
     * @param font  the font.
     */
    public MarkerAxisBand(NumberAxis axis,
                          double topOuterGap, double topInnerGap,
                          double bottomOuterGap, double bottomInnerGap,
                          Font font) {
        this.axis = axis;
        this.topOuterGap = topOuterGap;
        this.topInnerGap = topInnerGap;
        this.bottomOuterGap = bottomOuterGap;
        this.bottomInnerGap = bottomInnerGap;
        this.font = font;
        this.markers = new java.util.ArrayList();
    }

    /**
     * Adds a marker to the band.
     *
     * @param marker  the marker.
     */
    public void addMarker(IntervalMarker marker) {
        this.markers.add(marker);
    }

    /**
     * Returns the height of the band.
     *
     * @param g2  the graphics device.
     *
     * @return The height of the band.
     */
    public double getHeight(Graphics2D g2) {

        double result = 0.0;
        if (this.markers.size() > 0) {
            LineMetrics metrics = this.font.getLineMetrics(
                "123g", g2.getFontRenderContext()
            );
            result = this.topOuterGap + this.topInnerGap + metrics.getHeight()
                     + this.bottomInnerGap + this.bottomOuterGap;
        }
        return result;

    }

    /**
     * A utility method that draws a string inside a rectangle.
     *
     * @param g2  the graphics device.
     * @param bounds  the rectangle.
     * @param font  the font.
     * @param text  the text.
     */
    private void drawStringInRect(Graphics2D g2, Rectangle2D bounds, Font font,
                                  String text) {

        g2.setFont(font);
        FontMetrics fm = g2.getFontMetrics(font);
        Rectangle2D r = TextUtilities.getTextBounds(text, g2, fm);
        double x = bounds.getX();
        if (r.getWidth() < bounds.getWidth()) {
            x = x + (bounds.getWidth() - r.getWidth()) / 2;
        }
        LineMetrics metrics = font.getLineMetrics(
            text, g2.getFontRenderContext()
        );
        g2.drawString(
            text, (float) x, (float) (bounds.getMaxY()
                - this.bottomInnerGap - metrics.getDescent())
        );
    }

    /**
     * Draws the band.
     *
     * @param g2  the graphics device.
     * @param plotArea  the plot area.
     * @param dataArea  the data area.
     * @param x  the x-coordinate.
     * @param y  the y-coordinate.
     */
    public void draw(Graphics2D g2, Rectangle2D plotArea, Rectangle2D dataArea,
                     double x, double y) {

        double h = getHeight(g2);
        Iterator iterator = this.markers.iterator();
        while (iterator.hasNext()) {
            IntervalMarker marker = (IntervalMarker) iterator.next();
            double start =  Math.max(
                marker.getStartValue(), this.axis.getRange().getLowerBound()
            );
            double end = Math.min(
                marker.getEndValue(), this.axis.getRange().getUpperBound()
            );
            double s = this.axis.valueToJava2D(
                start, dataArea, RectangleEdge.BOTTOM
            );
            double e = this.axis.valueToJava2D(
                end, dataArea, RectangleEdge.BOTTOM
            );
            Rectangle2D r = new Rectangle2D.Double(
                s, y + this.topOuterGap, e - s,
                h - this.topOuterGap - this.bottomOuterGap
            );

            Composite originalComposite = g2.getComposite();
            g2.setComposite(AlphaComposite.getInstance(
                AlphaComposite.SRC_OVER, marker.getAlpha())
            );
            g2.setPaint(marker.getPaint());
            g2.fill(r);
            g2.setPaint(marker.getOutlinePaint());
            g2.draw(r);
            g2.setComposite(originalComposite);

            g2.setPaint(Color.black);
            drawStringInRect(g2, r, this.font, marker.getLabel());
        }

    }

    /**
     * Tests this axis for equality with another object.  Note that the axis
     * that the band belongs to is ignored in the test.
     *
     * @param obj  the object (<code>null permitted).
     *
     * @return <code>true or false.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof MarkerAxisBand)) {
            return false;
        }
        MarkerAxisBand that = (MarkerAxisBand) obj;
        if (this.topOuterGap != that.topOuterGap) {
            return false;
        }
        if (this.topInnerGap != that.topInnerGap) {
            return false;
        }
        if (this.bottomInnerGap != that.bottomInnerGap) {
            return false;
        }
        if (this.bottomOuterGap != that.bottomOuterGap) {
            return false;
        }
        if (!ObjectUtilities.equal(this.font, that.font)) {
            return false;
        }
        if (!ObjectUtilities.equal(this.markers, that.markers)) {
            return false;
        }
        return true;
    }

    /**
     * Returns a hash code for the object.
     *
     * @return A hash code.
     */
    public int hashCode() {
        int result = 37;
        result = 19 * result + this.font.hashCode();
        result = 19 * result + this.markers.hashCode();
        return result;
    }

}