Source for org.jfree.chart.needle.PlumNeedle

   1: /* ===========================================================
   2:  * JFreeChart : a free chart library for the Java(tm) platform
   3:  * ===========================================================
   4:  *
   5:  * (C) Copyright 2000-2006, 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:  * PlumNeedle.java
  29:  * ---------------
  30:  * (C) Copyright 2002-2006, by the Australian Antarctic Division and 
  31:  *                          Contributors.
  32:  *
  33:  * Original Author:  Bryan Scott (for the Australian Antarctic Division);
  34:  * Contributor(s):   David Gilbert (for Object Refinery Limited);
  35:  *
  36:  * $Id: PlumNeedle.java,v 1.4.2.3 2006/08/02 10:40:57 mungady Exp $
  37:  *
  38:  * Changes:
  39:  * --------
  40:  * 25-Sep-2002 : Version 1, contributed by Bryan Scott (DG);
  41:  * 27-Mar-2003 : Implemented Serializable (DG);
  42:  * 09-Sep-2003 : Added equals() method (DG);
  43:  * 08-Jun-2005 : Implemented Cloneable (DG);
  44:  *
  45:  */
  46: 
  47: package org.jfree.chart.needle;
  48: 
  49: import java.awt.Graphics2D;
  50: import java.awt.geom.Arc2D;
  51: import java.awt.geom.Area;
  52: import java.awt.geom.Point2D;
  53: import java.awt.geom.Rectangle2D;
  54: import java.io.Serializable;
  55: 
  56: /**
  57:  * A needle for use with the {@link org.jfree.chart.plot.CompassPlot} class.
  58:  */
  59: public class PlumNeedle extends MeterNeedle 
  60:                         implements Cloneable, Serializable {
  61: 
  62:     /** For serialization. */
  63:     private static final long serialVersionUID = -3082660488660600718L;
  64:     
  65:     /**
  66:      * Draws the needle.
  67:      *
  68:      * @param g2  the graphics device.
  69:      * @param plotArea  the plot area.
  70:      * @param rotate  the rotation point.
  71:      * @param angle  the angle.
  72:      */
  73:     protected void drawNeedle(Graphics2D g2, Rectangle2D plotArea, 
  74:                               Point2D rotate, double angle) {
  75: 
  76:         Arc2D shape = new Arc2D.Double(Arc2D.PIE);
  77:         double radius = plotArea.getHeight();
  78:         double halfX = plotArea.getWidth() / 2;
  79:         double diameter = 2 * radius;
  80: 
  81:         shape.setFrame(plotArea.getMinX() + halfX - radius ,
  82:                        plotArea.getMinY() - radius,
  83:                        diameter, diameter);
  84:         radius = Math.toDegrees(Math.asin(halfX / radius));
  85:         shape.setAngleStart(270 - radius);
  86:         shape.setAngleExtent(2 * radius);
  87: 
  88:         Area s = new Area(shape);
  89: 
  90:         if ((rotate != null) && (angle != 0)) {
  91:             /// we have rotation houston, please spin me
  92:             getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
  93:             s.transform(getTransform());
  94:         }
  95: 
  96:         defaultDisplay(g2, s);
  97:     }
  98:     
  99:     /**
 100:      * Tests another object for equality with this object.
 101:      * 
 102:      * @param obj  the object to test (<code>null</code> permitted).
 103:      * 
 104:      * @return A boolean.
 105:      */
 106:     public boolean equals(Object obj) {
 107:         if (obj == this) {
 108:             return true;
 109:         }
 110:         if (!(obj instanceof PlumNeedle)) {
 111:             return false;   
 112:         }
 113:         if (!super.equals(obj)) {
 114:             return false;
 115:         }
 116:         return true;
 117:     }
 118: 
 119:     /**
 120:      * Returns a clone of this needle.
 121:      * 
 122:      * @return A clone.
 123:      * 
 124:      * @throws CloneNotSupportedException if the <code>PlumNeedle</code> 
 125:      *     cannot be cloned (in theory, this should not happen).
 126:      */
 127:     public Object clone() throws CloneNotSupportedException {
 128:         return super.clone();   
 129:     }
 130: 
 131: }