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Java > Open Source Codes > org > jfree > chart > block > EmptyBlock


1 /* ===========================================================
2  * JFreeChart : a free chart library for the Java(tm) platform
3  * ===========================================================
4  *
5  * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
6  *
7  * Project Info: http://www.jfree.org/jfreechart/index.html
8  *
9  * This library is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU Lesser General Public License as published by
11  * the Free Software Foundation; either version 2.1 of the License, or
12  * (at your option) any later version.
13  *
14  * This library is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
17  * License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with this library; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
22  * USA.
23  *
24  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
25  * in the United States and other countries.]
26  *
27  * ---------------
28  * EmptyBlock.java
29  * ---------------
30  * (C) Copyright 2004, 2005, by Object Refinery Limited.
31  *
32  * Original Author: David Gilbert (for Object Refinery Limited);
33  * Contributor(s): -;
34  *
35  * $Id: EmptyBlock.java,v 1.4.2.1 2005/10/25 20:39:38 mungady Exp $
36  *
37  * Changes:
38  * --------
39  * 22-Oct-2004 : Version 1 (DG);
40  * 04-Feb-2005 : Now cloneable and serializable (DG);
41  * 20-Apr-2005 : Added new draw() method (DG);
42  *
43  */
44
45 package org.jfree.chart.block;
46
47 import java.awt.Graphics2D JavaDoc;
48 import java.awt.geom.Rectangle2D JavaDoc;
49 import java.io.Serializable JavaDoc;
50
51 import org.jfree.util.PublicCloneable;
52
53 /**
54  * An empty block with a fixed size.
55  */
56 public class EmptyBlock extends AbstractBlock
57                         implements Block, Cloneable JavaDoc, PublicCloneable,
58                                    Serializable JavaDoc {
59     
60     /** For serialization. */
61     private static final long serialVersionUID = -4083197869412648579L;
62     
63     /**
64      * Creates a new block with the specified width and height.
65      *
66      * @param width the width.
67      * @param height the height.
68      */
69     public EmptyBlock(double width, double height) {
70         setWidth(width);
71         setHeight(height);
72     }
73
74     /**
75      * Draws the block. Since the block is empty, this method does nothing.
76      *
77      * @param g2 the graphics device.
78      * @param area the area.
79      */
80     public void draw(Graphics2D JavaDoc g2, Rectangle2D JavaDoc area) {
81         // do nothing, we're empty
82 }
83     
84     /**
85      * Draws the block within the specified area. Since the block is empty,
86      * this method does nothing.
87      *
88      * @param g2 the graphics device.
89      * @param area the area.
90      * @param params ignored (<code>null</code> permitted).
91      *
92      * @return Always <code>null</code>.
93      */
94     public Object JavaDoc draw(Graphics2D JavaDoc g2, Rectangle2D JavaDoc area, Object JavaDoc params) {
95         return null;
96     }
97
98     /**
99      * Returns a clone of the block.
100      *
101      * @return A clone.
102      *
103      * @throws CloneNotSupportedException if there is a problem cloning.
104      */
105     public Object JavaDoc clone() throws CloneNotSupportedException JavaDoc {
106         return super.clone();
107     }
108
109 }
110
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