001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
006 *
007 * Project Info:  http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it 
010 * under the terms of the GNU Lesser General Public License as published by 
011 * the Free Software Foundation; either version 2.1 of the License, or 
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but 
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
022 * USA.  
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
025 * in the United States and other countries.]
026 *
027 * ---------------
028 * EmptyBlock.java
029 * ---------------
030 * (C) Copyright 2004-2007, by Object Refinery Limited.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * Changes:
036 * --------
037 * 22-Oct-2004 : Version 1 (DG);
038 * 04-Feb-2005 : Now cloneable and serializable (DG);
039 * 20-Apr-2005 : Added new draw() method (DG);
040 * 
041 */
042
043package org.jfree.chart.block;
044
045import java.awt.Graphics2D;
046import java.awt.geom.Rectangle2D;
047import java.io.Serializable;
048
049import org.jfree.util.PublicCloneable;
050
051/**
052 * An empty block with a fixed size.
053 */
054public class EmptyBlock extends AbstractBlock 
055                        implements Block, Cloneable, PublicCloneable,
056                                   Serializable {
057    
058    /** For serialization. */
059    private static final long serialVersionUID = -4083197869412648579L;
060    
061    /**
062     * Creates a new block with the specified width and height.
063     * 
064     * @param width  the width.
065     * @param height  the height.
066     */
067    public EmptyBlock(double width, double height) {
068        setWidth(width);
069        setHeight(height);
070    }
071
072    /**
073     * Draws the block.  Since the block is empty, this method does nothing.
074     * 
075     * @param g2  the graphics device.
076     * @param area  the area.
077     */
078    public void draw(Graphics2D g2, Rectangle2D area) {
079        // do nothing, we're empty
080    }
081    
082    /**
083     * Draws the block within the specified area.  Since the block is empty, 
084     * this method does nothing.
085     * 
086     * @param g2  the graphics device.
087     * @param area  the area.
088     * @param params  ignored (<code>null</code> permitted).
089     * 
090     * @return Always <code>null</code>.
091     */
092    public Object draw(Graphics2D g2, Rectangle2D area, Object params) {
093        return null;
094    }
095
096    /**
097     * Returns a clone of the block.
098     * 
099     * @return A clone.
100     * 
101     * @throws CloneNotSupportedException if there is a problem cloning.
102     */
103    public Object clone() throws CloneNotSupportedException {
104        return super.clone();   
105    }
106
107}