Source for 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;
  48: import java.awt.geom.Rectangle2D;
  49: import java.io.Serializable;
  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, PublicCloneable,
  58:                                    Serializable {
  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 g2, Rectangle2D 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 draw(Graphics2D g2, Rectangle2D area, Object 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 clone() throws CloneNotSupportedException {
 106:         return super.clone();   
 107:     }
 108: 
 109: }