Source for org.jfree.chart.needle.ArrowNeedle

   1: /* ===========================================================
   2:  * JFreeChart : a free chart library for the Java(tm) platform
   3:  * ===========================================================
   4:  *
   5:  * (C) Copyright 2000-2007, 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:  * ArrowNeedle.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:  */
  43: 
  44: package org.jfree.chart.needle;
  45: 
  46: import java.awt.Graphics2D;
  47: import java.awt.Shape;
  48: import java.awt.geom.GeneralPath;
  49: import java.awt.geom.Line2D;
  50: import java.awt.geom.Point2D;
  51: import java.awt.geom.Rectangle2D;
  52: import java.io.Serializable;
  53: 
  54: /**
  55:  * A needle in the shape of an arrow.
  56:  */
  57: public class ArrowNeedle extends MeterNeedle 
  58:                          implements Cloneable, Serializable {
  59: 
  60:     /** For serialization. */
  61:     private static final long serialVersionUID = -5334056511213782357L;
  62:     
  63:     /** 
  64:      * A flag controlling whether or not there is an arrow at the top of the 
  65:      * needle. 
  66:      */
  67:     private boolean isArrowAtTop = true;
  68: 
  69:     /**
  70:      * Constructs a new arrow needle.
  71:      *
  72:      * @param isArrowAtTop  a flag that controls whether or not there is an 
  73:      *                      arrow at the top of the needle.
  74:      */
  75:     public ArrowNeedle(boolean isArrowAtTop) {
  76:         this.isArrowAtTop = isArrowAtTop;
  77:     }
  78: 
  79:     /**
  80:      * Draws the needle.
  81:      *
  82:      * @param g2  the graphics device.
  83:      * @param plotArea  the plot area.
  84:      * @param rotate  the rotation point.
  85:      * @param angle  the angle.
  86:      */
  87:     protected void drawNeedle(Graphics2D g2, Rectangle2D plotArea, 
  88:                               Point2D rotate, double angle) {
  89: 
  90:         Line2D shape = new Line2D.Float();
  91:         Shape d = null;
  92: 
  93:         float x = (float) (plotArea.getMinX() +  (plotArea.getWidth() / 2));
  94:         float minY = (float) plotArea.getMinY();
  95:         float maxY = (float) plotArea.getMaxY();
  96:         shape.setLine(x, minY, x, maxY);
  97: 
  98:         GeneralPath shape1 = new GeneralPath();
  99:         if (this.isArrowAtTop) {
 100:             shape1.moveTo(x, minY);
 101:             minY += 4 * getSize();
 102:         }
 103:         else {
 104:             shape1.moveTo(x, maxY);
 105:             minY = maxY - 4 * getSize();
 106:         }
 107:         shape1.lineTo(x + getSize(), minY);
 108:         shape1.lineTo(x - getSize(), minY);
 109:         shape1.closePath();
 110: 
 111:         if ((rotate != null) && (angle != 0)) {
 112:             getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
 113:             d = getTransform().createTransformedShape(shape);
 114:         }
 115:         else {
 116:             d = shape;
 117:         }
 118:         defaultDisplay(g2, d);
 119: 
 120:         if ((rotate != null) && (angle != 0)) {
 121:             d = getTransform().createTransformedShape(shape1);
 122:         }
 123:         else {
 124:             d = shape1;
 125:         }
 126:         defaultDisplay(g2, d);
 127: 
 128:     }
 129: 
 130:     /**
 131:      * Tests another object for equality with this object.
 132:      * 
 133:      * @param obj  the object to test (<code>null</code> permitted).
 134:      * 
 135:      * @return A boolean.
 136:      */
 137:     public boolean equals(Object obj) {
 138:         if (obj == this) {
 139:             return true;
 140:         }
 141:         if (!(obj instanceof ArrowNeedle)) {
 142:             return false; 
 143:         }
 144:         if (!super.equals(obj)) {
 145:             return false;
 146:         }
 147:         ArrowNeedle that = (ArrowNeedle) obj;
 148:         if (this.isArrowAtTop != that.isArrowAtTop) {
 149:             return false;
 150:         }
 151:         return true;
 152:     }
 153:     
 154:     /**
 155:      * Returns a clone of this needle.
 156:      * 
 157:      * @return A clone.
 158:      * 
 159:      * @throws CloneNotSupportedException if the <code>ArrowNeedle</code> 
 160:      *     cannot be cloned (in theory, this should not happen).
 161:      */
 162:     public Object clone() throws CloneNotSupportedException {
 163:         return super.clone();   
 164:     }
 165:     
 166: }