jfreechart example source code file (DialLayer.java)

This example jfreechart source code file (DialLayer.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, diallayer, diallayer, dialplot, dialplot, geometry, io, rectangle2d, rectangle2d, util

The jfreechart DialLayer.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.]
 *
 * --------------
 * DialLayer.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);
 *
 */

package org.jfree.chart.plot.dial;

import java.awt.Graphics2D;
import java.awt.geom.Rectangle2D;
import java.io.Serializable;
import java.util.EventListener;

/**
 * A dial layer draws itself within a reference frame.  The view frame is a
 * subset of the reference frame, and defines the area that is actually
 * visible.
 * <br>

 * Classes that implement this interface should be {@link Serializable},
 * otherwise chart serialization may fail.
 *
 * @since 1.0.7
 */
public interface DialLayer {

    /**
     * Returns a flag that indicates whether or not the layer is visible.
     *
     * @return A boolean.
     */
    public boolean isVisible();

    /**
     * Registers a listener with this layer, so that it receives notification
     * of changes to this layer.
     *
     * @param listener  the listener.
     */
    public void addChangeListener(DialLayerChangeListener listener);

    /**
     * Deregisters a listener, so that it no longer receives notification of
     * changes to this layer.
     *
     * @param listener  the listener.
     */
    public void removeChangeListener(DialLayerChangeListener listener);

    /**
     * Returns <code>true if the specified listener is currently
     * registered with the this layer.
     *
     * @param listener  the listener.
     *
     * @return A boolean.
     */
    public boolean hasListener(EventListener listener);

    /**
     * Returns <code>true if the drawing should be clipped to the
     * dial window (which is defined by the {@link DialFrame}), and
     * <code>false otherwise.
     *
     * @return A boolean.
     */
    public boolean isClippedToWindow();

    /**
     * Draws the content of this layer.
     *
     * @param g2  the graphics target (<code>null not permitted).
     * @param plot  the plot (typically this should not be <code>null,
     *     but for a layer that doesn't need to reference the plot, it may
     *     be permitted).
     * @param frame  the reference frame for the dial's geometry
     *     (<code>null not permitted).  This is typically larger than
     *     the visible area of the dial (see the next parameter).
     * @param view  the visible area for the dial (<code>null not
     *     permitted).
     */
    public void draw(Graphics2D g2, DialPlot plot, Rectangle2D frame,
            Rectangle2D view);

}