jfreechart example source code file (DialBackground.java)

This example jfreechart source code file (DialBackground.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, clonenotsupportedexception, dialbackground, dialbackground, diallayer, diallayerchangeevent, geometry, gradientpainttransformer, illegalargumentexception, illegalargumentexception, io, ioexception, null, null, paint, paint, rectangle2d

The jfreechart DialBackground.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.]
 *
 * -------------------
 * DialBackground.java
 * -------------------
 * (C) Copyright 2006-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 03-Nov-2006 : Version 1 (DG);
 * 16-Oct-2007 : The equals() method needs to call super.equals() (DG);
 *
 */

package org.jfree.chart.plot.dial;

import java.awt.Color;
import java.awt.GradientPaint;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.geom.Rectangle2D;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

import org.jfree.chart.HashUtilities;
import org.jfree.io.SerialUtilities;
import org.jfree.ui.GradientPaintTransformer;
import org.jfree.ui.StandardGradientPaintTransformer;
import org.jfree.util.PaintUtilities;
import org.jfree.util.PublicCloneable;

/**
 * A regular dial layer that can be used to draw the background for a dial.
 *
 * @since 1.0.7
 */
public class DialBackground extends AbstractDialLayer implements DialLayer,
        Cloneable, PublicCloneable, Serializable {

    /** For serialization. */
    static final long serialVersionUID = -9019069533317612375L;

    /**
     * The background paint.  This field is transient because serialization
     * requires special handling.
     */
    private transient Paint paint;

    /**
     * The transformer used when the background paint is an instance of
     * <code>GradientPaint.
     */
    private GradientPaintTransformer gradientPaintTransformer;

    /**
     * Creates a new instance of <code>DialBackground.  The
     * default background paint is <code>Color.white.
     */
    public DialBackground() {
        this(Color.white);
    }

    /**
     * Creates a new instance of <code>DialBackground.  The
     *
     * @param paint  the paint (<code>null not permitted).
     *
     * @throws IllegalArgumentException if <code>paint is
     *     <code>null.
     */
    public DialBackground(Paint paint) {
        if (paint == null) {
            throw new IllegalArgumentException("Null 'paint' argument.");
        }
        this.paint = paint;
        this.gradientPaintTransformer = new StandardGradientPaintTransformer();
    }

    /**
     * Returns the paint used to fill the background.
     *
     * @return The paint (never <code>null).
     *
     * @see #setPaint(Paint)
     */
    public Paint getPaint() {
        return this.paint;
    }

    /**
     * Sets the paint for the dial background and sends a
     * {@link DialLayerChangeEvent} to all registered listeners.
     *
     * @param paint  the paint (<code>null not permitted).
     *
     * @see #getPaint()
     */
    public void setPaint(Paint paint) {
        if (paint == null) {
            throw new IllegalArgumentException("Null 'paint' argument.");
        }
        this.paint = paint;
        notifyListeners(new DialLayerChangeEvent(this));
    }

    /**
     * Returns the transformer used to adjust the coordinates of any
     * <code>GradientPaint instance used for the background paint.
     *
     * @return The transformer (never <code>null).
     *
     * @see #setGradientPaintTransformer(GradientPaintTransformer)
     */
    public GradientPaintTransformer getGradientPaintTransformer() {
        return this.gradientPaintTransformer;
    }

    /**
     * Sets the transformer used to adjust the coordinates of any
     * <code>GradientPaint instance used for the background paint, and
     * sends a {@link DialLayerChangeEvent} to all registered listeners.
     *
     * @param t  the transformer (<code>null not permitted).
     *
     * @see #getGradientPaintTransformer()
     */
    public void setGradientPaintTransformer(GradientPaintTransformer t) {
        if (t == null) {
            throw new IllegalArgumentException("Null 't' argument.");
        }
        this.gradientPaintTransformer = t;
        notifyListeners(new DialLayerChangeEvent(this));
    }

    /**
     * Returns <code>true to indicate that this layer should be
     * clipped within the dial window.
     *
     * @return <code>true.
     */
    public boolean isClippedToWindow() {
        return true;
    }

    /**
     * Draws the background to the specified graphics device.  If the dial
     * frame specifies a window, the clipping region will already have been
     * set to this window before this method is called.
     *
     * @param g2  the graphics device (<code>null not permitted).
     * @param plot  the plot (ignored here).
     * @param frame  the dial frame (ignored here).
     * @param view  the view rectangle (<code>null not permitted).
     */
    public void draw(Graphics2D g2, DialPlot plot, Rectangle2D frame,
            Rectangle2D view) {

        Paint p = this.paint;
        if (p instanceof GradientPaint) {
            p = this.gradientPaintTransformer.transform((GradientPaint) p,
                    view);
        }
        g2.setPaint(p);
        g2.fill(view);
    }

    /**
     * Tests this instance 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 DialBackground)) {
            return false;
        }
        DialBackground that = (DialBackground) obj;
        if (!PaintUtilities.equal(this.paint, that.paint)) {
            return false;
        }
        if (!this.gradientPaintTransformer.equals(
                that.gradientPaintTransformer)) {
            return false;
        }
        return super.equals(obj);
    }

    /**
     * Returns a hash code for this instance.
     *
     * @return The hash code.
     */
    public int hashCode() {
        int result = 193;
        result = 37 * result + HashUtilities.hashCodeForPaint(this.paint);
        result = 37 * result + this.gradientPaintTransformer.hashCode();
        return result;
    }

    /**
     * Returns a clone of this instance.
     *
     * @return The clone.
     *
     * @throws CloneNotSupportedException if some attribute of this instance
     *     cannot be cloned.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }

    /**
     * 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.writePaint(this.paint, stream);
    }

    /**
     * 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.paint = SerialUtilities.readPaint(stream);
    }

}