Source for org.jfree.chart.block.EmptyBlock

   1: /* ===========================================================
   2:  * JFreeChart : a free chart library for the Java(tm) platform
   3:  * ===========================================================
   4:  *
   5:  * (C) Copyright 2000-2007, 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 2004-2007, by Object Refinery Limited.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   -;
  34:  *
  35:  * Changes:
  36:  * --------
  37:  * 22-Oct-2004 : Version 1 (DG);
  38:  * 04-Feb-2005 : Now cloneable and serializable (DG);
  39:  * 20-Apr-2005 : Added new draw() method (DG);
  40:  * 
  41:  */
  42: 
  43: package org.jfree.chart.block;
  44: 
  45: import java.awt.Graphics2D;
  46: import java.awt.geom.Rectangle2D;
  47: import java.io.Serializable;
  48: 
  49: import org.jfree.util.PublicCloneable;
  50: 
  51: /**
  52:  * An empty block with a fixed size.
  53:  */
  54: public class EmptyBlock extends AbstractBlock 
  55:                         implements Block, Cloneable, PublicCloneable,
  56:                                    Serializable {
  57:     
  58:     /** For serialization. */
  59:     private static final long serialVersionUID = -4083197869412648579L;
  60:     
  61:     /**
  62:      * Creates a new block with the specified width and height.
  63:      * 
  64:      * @param width  the width.
  65:      * @param height  the height.
  66:      */
  67:     public EmptyBlock(double width, double height) {
  68:         setWidth(width);
  69:         setHeight(height);
  70:     }
  71: 
  72:     /**
  73:      * Draws the block.  Since the block is empty, this method does nothing.
  74:      * 
  75:      * @param g2  the graphics device.
  76:      * @param area  the area.
  77:      */
  78:     public void draw(Graphics2D g2, Rectangle2D area) {
  79:         // do nothing, we're empty
  80:     }
  81:     
  82:     /**
  83:      * Draws the block within the specified area.  Since the block is empty, 
  84:      * this method does nothing.
  85:      * 
  86:      * @param g2  the graphics device.
  87:      * @param area  the area.
  88:      * @param params  ignored (<code>null</code> permitted).
  89:      * 
  90:      * @return Always <code>null</code>.
  91:      */
  92:     public Object draw(Graphics2D g2, Rectangle2D area, Object params) {
  93:         return null;
  94:     }
  95: 
  96:     /**
  97:      * Returns a clone of the block.
  98:      * 
  99:      * @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: }