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Java > Open Source Codes > org > jfree > chart > needle > PlumNeedle


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 License
20  * along with this library; if not, write to the Free Software Foundation,
21  * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
22  *
23  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
24  * in the United States and other countries.]
25  *
26  * ---------------
27  * PlumNeedle.java
28  * ---------------
29  * (C) Copyright 2002-2005, by the Australian Antarctic Division and
30  * Contributors.
31  *
32  * Original Author: Bryan Scott (for the Australian Antarctic Division);
33  * Contributor(s): David Gilbert (for Object Refinery Limited);
34  *
35  * $Id: PlumNeedle.java,v 1.4 2005/05/19 15:42:54 mungady Exp $
36  *
37  * Changes:
38  * --------
39  * 25-Sep-2002 : Version 1, contributed by Bryan Scott (DG);
40  * 27-Mar-2003 : Implemented Serializable (DG);
41  * 09-Sep-2003 : Added equals() method (DG);
42  *
43  */
44
45 package org.jfree.chart.needle;
46
47 import java.awt.Graphics2D JavaDoc;
48 import java.awt.geom.Arc2D JavaDoc;
49 import java.awt.geom.Area JavaDoc;
50 import java.awt.geom.Point2D JavaDoc;
51 import java.awt.geom.Rectangle2D JavaDoc;
52 import java.io.Serializable JavaDoc;
53
54 /**
55  * A needle for use with the {@link org.jfree.chart.plot.CompassPlot} class.
56  *
57  * @author Bryan Scott
58  */
59 public class PlumNeedle extends MeterNeedle implements Serializable JavaDoc {
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 JavaDoc g2, Rectangle2D JavaDoc plotArea,
73                               Point2D JavaDoc rotate, double angle) {
74
75         Arc2D JavaDoc shape = new Arc2D.Double JavaDoc(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 JavaDoc s = new Area JavaDoc(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 object the object to test.
102      *
103      * @return A boolean.
104      */
105     public boolean equals(Object JavaDoc object) {
106         if (object == null) {
107             return false;
108         }
109         if (object == this) {
110             return true;
111         }
112         if (super.equals(object) && object instanceof PlumNeedle) {
113             return true;
114         }
115         return false;
116     }
117
118 }
119
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