libjava/java/awt/Dimension.java

   1 /* Dimension.java -- represents a 2-dimensional span
   2    Copyright (C) 1999, 2000, 2002 Free Software Foundation
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.awt;
  40
  41 import java.awt.geom.Dimension2D;
  42 import java.io.Serializable;
  43
  44 /**
  45  * This class holds a width and height value pair. This is used in plenty
  46  * of windowing classes, but also has geometric meaning.
  47  *
  48  * <p>It is valid for a dimension to have negative width or height; but it
  49  * is considered to have no area. Therefore, the behavior in various methods
  50  * is undefined in such a case.
  51  *
  52  * <p>There are some public fields; if you mess with them in an inconsistent
  53  * manner, it is your own fault when you get invalid results. Also, this
  54  * class is not threadsafe.
  55  *
  56  * @author Per Bothner (bothner@cygnus.com)
  57  * @author Aaron M. Renn (arenn@urbanophile.com)
  58  * @author Eric Blake (ebb9@email.byu.edu)
  59  * @see Component
  60  * @see LayoutManager
  61  * @since 1.0
  62  * @status updated to 1.14
  63  */
  64 public class Dimension extends Dimension2D implements Serializable
  65 {
  66   /**
  67    * Compatible with JDK 1.0+.
  68    */
  69   private static final long serialVersionUID = 4723952579491349524L;
  70
  71   /**
  72    * The width of this object.
  73    *
  74    * @see #getSize()
  75    * @see #setSize(double, double)
  76    * @serial the width
  77    */
  78   public int width;
  79
  80   /**
  81    * The height of this object.
  82    *
  83    * @see #getSize()
  84    * @see #setSize(double, double)
  85    * @serial the height
  86    */
  87   public int height;
  88
  89   /**
  90    * Create a new Dimension with a width and height of zero.
  91    */
  92   public Dimension()
  93   {
  94   }
  95
  96   /**
  97    * Create a new Dimension with width and height identical to that of the
  98    * specified dimension.
  99    *
 100    * @param d the Dimension to copy
 101    * @throws NullPointerException if d is null
 102    */
 103   public Dimension(Dimension d)
 104   {
 105     width = d.width;
 106     height = d.height;
 107   }
 108
 109   /**
 110    * Create a new Dimension with the specified width and height.
 111    *
 112    * @param w the width of this object
 113    * @param h the height of this object
 114    */
 115   public Dimension(int w, int h)
 116   {
 117     width = w;
 118     height = h;
 119   }
 120
 121   /**
 122    * Gets the width of this dimension.
 123    *
 124    * @return the width, as a double
 125    */
 126   public double getWidth()
 127   {
 128     return width;
 129   }
 130
 131   /**
 132    * Gets the height of this dimension.
 133    *
 134    * @return the height, as a double
 135    */
 136   public double getHeight()
 137   {
 138     return height;
 139   }
 140
 141   /**
 142    * Sets the size of this dimension. The values are rounded to int.
 143    *
 144    * @param w the new width
 145    * @param h the new height
 146    * @since 1.2
 147    */
 148   public void setSize(double w, double h)
 149   {
 150     width = (int) w;
 151     height = (int) h;
 152   }
 153
 154   /**
 155    * Returns the size of this dimension. A pretty useless method, as this is
 156    * already a dimension.
 157    *
 158    * @return a copy of this dimension
 159    * @see #setSize(Dimension)
 160    * @since 1.1
 161    */
 162   public Dimension getSize()
 163   {
 164     return new Dimension(width, height);
 165   }
 166
 167   /**
 168    * Sets the width and height of this object to match that of the
 169    * specified object.
 170    *
 171    * @param d the Dimension to get the new width and height from
 172    * @throws NullPointerException if d is null
 173    * @see #getSize()
 174    * @since 1.1
 175    */
 176   public void setSize(Dimension d)
 177   {
 178     width = d.width;
 179     height = d.height;
 180   }
 181
 182   /**
 183    * Sets the width and height of this object to the specified values.
 184    *
 185    * @param w the new width value
 186    * @param h the new height value
 187    */
 188   public void setSize(int w, int h)
 189   {
 190     width = w;
 191     height = h;
 192   }
 193
 194   /**
 195    * Tests this object for equality against the specified object.  This will
 196    * be true if and only if the specified object is an instance of
 197    * Dimension2D, and has the same width and height.
 198    *
 199    * @param obj the object to test against
 200    * @return true if the object is equal to this
 201    */
 202   public boolean equals(Object obj)
 203   {
 204     if (! (obj instanceof Dimension))
 205       return false;
 206     Dimension dim = (Dimension) obj;
 207     return height == dim.height && width == dim.width;
 208   }
 209
 210   /**
 211    * Return the hashcode for this object. It is not documented, but appears
 212    * to be <code>((width + height) * (width + height + 1) / 2) + width</code>.
 213    *
 214    * @return the hashcode
 215    */
 216   public int hashCode()
 217   {
 218     // Reverse engineering this was fun!
 219     return (width + height) * (width + height + 1) / 2 + width;
 220   }
 221
 222   /**
 223    * Returns a string representation of this object. The format is:
 224    * <code>getClass().getName() + "[width=" + width + ",height=" + height
 225    * + ']'</code>.
 226    *
 227    * @return a string representation of this object
 228    */
 229   public String toString()
 230   {
 231     return getClass().getName()
 232       + "[width=" + width + ",height=" + height + ']';
 233   }
 234 } // class Dimension