Source for org.jfree.chart.needle.ArrowNeedle

   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:  * ArrowNeedle.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: ArrowNeedle.java,v 1.3.2.3 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: package org.jfree.chart.needle;
  47: 
  48: import java.awt.Graphics2D;
  49: import java.awt.Shape;
  50: import java.awt.geom.GeneralPath;
  51: import java.awt.geom.Line2D;
  52: import java.awt.geom.Point2D;
  53: import java.awt.geom.Rectangle2D;
  54: import java.io.Serializable;
  55: 
  56: /**
  57:  * A needle in the shape of an arrow.
  58:  */
  59: public class ArrowNeedle extends MeterNeedle 
  60:                          implements Cloneable, Serializable {
  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 g2, Rectangle2D plotArea, 
  90:                               Point2D rotate, double angle) {
  91: 
  92:         Line2D shape = new Line2D.Float();
  93:         Shape 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 shape1 = new GeneralPath();
 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 obj  the object to test (<code>null</code> permitted).
 136:      * 
 137:      * @return A boolean.
 138:      */
 139:     public boolean equals(Object obj) {
 140:         if (obj == this) {
 141:             return true;
 142:         }
 143:         if (!(obj instanceof ArrowNeedle)) {
 144:             return false; 
 145:         }
 146:         if (!super.equals(obj)) {
 147:             return false;
 148:         }
 149:         ArrowNeedle that = (ArrowNeedle) obj;
 150:         if (this.isArrowAtTop != that.isArrowAtTop) {
 151:             return false;
 152:         }
 153:         return true;
 154:     }
 155:     
 156:     /**
 157:      * Returns a clone of this needle.
 158:      * 
 159:      * @return A clone.
 160:      * 
 161:      * @throws CloneNotSupportedException if the <code>ArrowNeedle</code> 
 162:      *     cannot be cloned (in theory, this should not happen).
 163:      */
 164:     public Object clone() throws CloneNotSupportedException {
 165:         return super.clone();   
 166:     }
 167:     
 168: }