001 /* Dimension.java -- represents a 2-dimensional span
002 Copyright (C) 1999, 2000, 2002 Free Software Foundation
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package java.awt;
040
041 import java.awt.geom.Dimension2D;
042 import java.io.Serializable;
043
044 /**
045 * This class holds a width and height value pair. This is used in plenty
046 * of windowing classes, but also has geometric meaning.
047 *
048 * <p>It is valid for a dimension to have negative width or height; but it
049 * is considered to have no area. Therefore, the behavior in various methods
050 * is undefined in such a case.
051 *
052 * <p>There are some public fields; if you mess with them in an inconsistent
053 * manner, it is your own fault when you get invalid results. Also, this
054 * class is not threadsafe.
055 *
056 * @author Per Bothner (bothner@cygnus.com)
057 * @author Aaron M. Renn (arenn@urbanophile.com)
058 * @author Eric Blake (ebb9@email.byu.edu)
059 * @see Component
060 * @see LayoutManager
061 * @since 1.0
062 * @status updated to 1.14
063 */
064 public class Dimension extends Dimension2D implements Serializable
065 {
066 /**
067 * Compatible with JDK 1.0+.
068 */
069 private static final long serialVersionUID = 4723952579491349524L;
070
071 /**
072 * The width of this object.
073 *
074 * @see #getSize()
075 * @see #setSize(double, double)
076 * @serial the width
077 */
078 public int width;
079
080 /**
081 * The height of this object.
082 *
083 * @see #getSize()
084 * @see #setSize(double, double)
085 * @serial the height
086 */
087 public int height;
088
089 /**
090 * Create a new Dimension with a width and height of zero.
091 */
092 public Dimension()
093 {
094 }
095
096 /**
097 * Create a new Dimension with width and height identical to that of the
098 * specified dimension.
099 *
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