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


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  * ArrowNeedle.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: ArrowNeedle.java,v 1.3 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.Shape JavaDoc;
49 import java.awt.geom.GeneralPath JavaDoc;
50 import java.awt.geom.Line2D JavaDoc;
51 import java.awt.geom.Point2D JavaDoc;
52 import java.awt.geom.Rectangle2D JavaDoc;
53 import java.io.Serializable JavaDoc;
54
55 /**
56  * A needle in the shape of an arrow.
57  *
58  * @author Bryan Scott
59  */
60 public class ArrowNeedle extends MeterNeedle implements Serializable JavaDoc {
61
62     /** For serialization. */
63     private static final long serialVersionUID = -5334056511213782357L;
64     
65     /**
66      * A flag controlling whether or not there is an arrow at the top of the
67      * needle.
68      */
69     private boolean isArrowAtTop = true;
70
71     /**
72      * Constructs a new arrow needle.
73      *
74      * @param isArrowAtTop a flag that controls whether or not there is an
75      * arrow at the top of the needle.
76      */
77     public ArrowNeedle(boolean isArrowAtTop) {
78         this.isArrowAtTop = isArrowAtTop;
79     }
80
81     /**
82      * Draws the needle.
83      *
84      * @param g2 the graphics device.
85      * @param plotArea the plot area.
86      * @param rotate the rotation point.
87      * @param angle the angle.
88      */
89     protected void drawNeedle(Graphics2D JavaDoc g2, Rectangle2D JavaDoc plotArea,
90                               Point2D JavaDoc rotate, double angle) {
91
92         Line2D JavaDoc shape = new Line2D.Float JavaDoc();
93         Shape JavaDoc d = null;
94
95         float x = (float) (plotArea.getMinX() + (plotArea.getWidth() / 2));
96         float minY = (float) plotArea.getMinY();
97         float maxY = (float) plotArea.getMaxY();
98         shape.setLine(x, minY, x, maxY);
99
100         GeneralPath JavaDoc shape1 = new GeneralPath JavaDoc();
101         if (this.isArrowAtTop) {
102             shape1.moveTo(x, minY);
103             minY += 4 * getSize();
104         }
105         else {
106             shape1.moveTo(x, maxY);
107             minY = maxY - 4 * getSize();
108         }
109         shape1.lineTo(x + getSize(), minY);
110         shape1.lineTo(x - getSize(), minY);
111         shape1.closePath();
112
113         if ((rotate != null) && (angle != 0)) {
114             getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
115             d = getTransform().createTransformedShape(shape);
116         }
117         else {
118             d = shape;
119         }
120         defaultDisplay(g2, d);
121
122         if ((rotate != null) && (angle != 0)) {
123             d = getTransform().createTransformedShape(shape1);
124         }
125         else {
126             d = shape1;
127         }
128         defaultDisplay(g2, d);
129
130     }
131
132     /**
133      * Tests another object for equality with this object.
134      *
135      * @param object the object to test.
136      *
137      * @return A boolean.
138      */
139     public boolean equals(Object JavaDoc object) {
140         if (object == null) {
141             return false;
142         }
143         if (object == this) {
144             return true;
145         }
146         if (super.equals(object) && object instanceof ArrowNeedle) {
147             ArrowNeedle an = (ArrowNeedle) object;
148             return this.isArrowAtTop == an.isArrowAtTop;
149         }
150         return false;
151     }
152     
153 }
154
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