Source for org.jfree.chart.needle.PlumNeedle

   1: /* ===========================================================
   2:  * JFreeChart : a free chart library for the Java(tm) platform
   3:  * ===========================================================
   4:  *
   5:  * (C) Copyright 2000-2007, 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:  * PlumNeedle.java
  29:  * ---------------
  30:  * (C) Copyright 2002-2007, 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:  * Changes:
  37:  * --------
  38:  * 25-Sep-2002 : Version 1, contributed by Bryan Scott (DG);
  39:  * 27-Mar-2003 : Implemented Serializable (DG);
  40:  * 09-Sep-2003 : Added equals() method (DG);
  41:  * 08-Jun-2005 : Implemented Cloneable (DG);
  42:  * 22-Nov-2007 : Implemented hashCode() (DG);
  43:  *
  44:  */
  45: 
  46: package org.jfree.chart.needle;
  47: 
  48: import java.awt.Graphics2D;
  49: import java.awt.geom.Arc2D;
  50: import java.awt.geom.Area;
  51: import java.awt.geom.Point2D;
  52: import java.awt.geom.Rectangle2D;
  53: import java.io.Serializable;
  54: 
  55: /**
  56:  * A needle for use with the {@link org.jfree.chart.plot.CompassPlot} class.
  57:  */
  58: public class PlumNeedle extends MeterNeedle 
  59:                         implements Cloneable, Serializable {
  60: 
  61:     /** For serialization. */
  62:     private static final long serialVersionUID = -3082660488660600718L;
  63:     
  64:     /**
  65:      * Draws the needle.
  66:      *
  67:      * @param g2  the graphics device.
  68:      * @param plotArea  the plot area.
  69:      * @param rotate  the rotation point.
  70:      * @param angle  the angle.
  71:      */
  72:     protected void drawNeedle(Graphics2D g2, Rectangle2D plotArea, 
  73:                               Point2D rotate, double angle) {
  74: 
  75:         Arc2D shape = new Arc2D.Double(Arc2D.PIE);
  76:         double radius = plotArea.getHeight();
  77:         double halfX = plotArea.getWidth() / 2;
  78:         double diameter = 2 * radius;
  79: 
  80:         shape.setFrame(plotArea.getMinX() + halfX - radius ,
  81:                        plotArea.getMinY() - radius,
  82:                        diameter, diameter);
  83:         radius = Math.toDegrees(Math.asin(halfX / radius));
  84:         shape.setAngleStart(270 - radius);
  85:         shape.setAngleExtent(2 * radius);
  86: 
  87:         Area s = new Area(shape);
  88: 
  89:         if ((rotate != null) && (angle != 0)) {
  90:             /// we have rotation houston, please spin me
  91:             getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
  92:             s.transform(getTransform());
  93:         }
  94: 
  95:         defaultDisplay(g2, s);
  96:     }
  97:     
  98:     /**
  99:      * Tests another object for equality with this object.
 100:      * 
 101:      * @param obj  the object to test (<code>null</code> permitted).
 102:      * 
 103:      * @return A boolean.
 104:      */
 105:     public boolean equals(Object obj) {
 106:         if (obj == this) {
 107:             return true;
 108:         }
 109:         if (!(obj instanceof PlumNeedle)) {
 110:             return false;   
 111:         }
 112:         if (!super.equals(obj)) {
 113:             return false;
 114:         }
 115:         return true;
 116:     }
 117: 
 118:     /**
 119:      * Returns a hash code for this instance.
 120:      * 
 121:      * @return A hash code.
 122:      */
 123:     public int hashCode() {
 124:         return super.hashCode();
 125:     }
 126: 
 127:     /**
 128:      * Returns a clone of this needle.
 129:      * 
 130:      * @return A clone.
 131:      * 
 132:      * @throws CloneNotSupportedException if the <code>PlumNeedle</code> 
 133:      *     cannot be cloned (in theory, this should not happen).
 134:      */
 135:     public Object clone() throws CloneNotSupportedException {
 136:         return super.clone();   
 137:     }
 138: 
 139: }