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
043 package org.jfree.chart.block;
044
045 import java.awt.Graphics2D;
046 import java.awt.geom.Rectangle2D;
047 import java.io.Serializable;
048
049 import org.jfree.util.PublicCloneable;
050
051 /**
052 * An empty block with a fixed size.
053 */
054 public 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 }