1 /* Point.java -- represents a point in 2-D space
2 Copyright (C) 1999, 2002 Free Software Foundation
4 This file is part of GNU Classpath.
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)
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.
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., 51 Franklin Street, Fifth Floor, Boston, MA
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
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. */
41 import java
.awt
.geom
.Point2D
;
42 import java
.io
.Serializable
;
45 * This class represents a point on the screen using cartesian coordinates.
46 * Remember that in screen coordinates, increasing x values go from left to
47 * right, and increasing y values go from top to bottom.
49 * <p>There are some public fields; if you mess with them in an inconsistent
50 * manner, it is your own fault when you get invalid results. Also, this
51 * class is not threadsafe.
53 * @author Per Bothner (bothner@cygnus.com)
54 * @author Aaron M. Renn (arenn@urbanophile.com)
55 * @author Eric Blake (ebb9@email.byu.edu)
57 * @status updated to 1.4
59 public class Point
extends Point2D
implements Serializable
62 * Compatible with JDK 1.0+.
64 private static final long serialVersionUID
= -5276940640259749850L;
70 * @see #move(int, int)
71 * @serial the X coordinate of the point
79 * @see #move(int, int)
80 * @serial The Y coordinate of the point
85 * Initializes a new instance of <code>Point</code> representing the
95 * Initializes a new instance of <code>Point</code> with coordinates
96 * identical to the coordinates of the specified points.
98 * @param p the point to copy the coordinates from
99 * @throws NullPointerException if p is null
101 public Point(Point p
)
108 * Initializes a new instance of <code>Point</code> with the specified
111 * @param x the X coordinate
112 * @param y the Y coordinate
114 public Point(int x
, int y
)
121 * Get the x coordinate.
123 * @return the value of x, as a double
131 * Get the y coordinate.
133 * @return the value of y, as a double
141 * Returns the location of this point. A pretty useless method, as this
142 * is already a point.
144 * @return a copy of this point
145 * @see #setLocation(Point)
148 public Point
getLocation()
150 return new Point(x
, y
);
154 * Sets this object's coordinates to match those of the specified point.
156 * @param p the point to copy the coordinates from
157 * @throws NullPointerException if p is null
160 public void setLocation(Point p
)
167 * Sets this object's coordinates to the specified values. This method
168 * is identical to the <code>move()</code> method.
170 * @param x the new X coordinate
171 * @param y the new Y coordinate
173 public void setLocation(int x
, int y
)
180 * Sets this object's coordinates to the specified values. This method
181 * performs normal casting from double to int, so you may lose precision.
183 * @param x the new X coordinate
184 * @param y the new Y coordinate
186 public void setLocation(double x
, double y
)
193 * Sets this object's coordinates to the specified values. This method
194 * is identical to the <code>setLocation(int, int)</code> method.
196 * @param x the new X coordinate
197 * @param y the new Y coordinate
199 public void move(int x
, int y
)
206 * Changes the coordinates of this point such that the specified
207 * <code>dx</code> parameter is added to the existing X coordinate and
208 * <code>dy</code> is added to the existing Y coordinate.
210 * @param dx the amount to add to the X coordinate
211 * @param dy the amount to add to the Y coordinate
213 public void translate(int dx
, int dy
)
220 * Tests whether or not this object is equal to the specified object.
221 * This will be true if and only if the specified object is an instance
222 * of Point2D and has the same X and Y coordinates.
224 * @param obj the object to test against for equality
225 * @return true if the specified object is equal
227 public boolean equals(Object obj
)
229 // NOTE: No special hashCode() method is required for this class,
230 // as this equals() implementation is functionally equivalent to
231 // super.equals(), which does define a proper hashCode().
233 if (! (obj
instanceof Point2D
))
235 Point2D p
= (Point2D
) obj
;
236 return x
== p
.getX() && y
== p
.getY();
240 * Returns a string representation of this object. The format is:
241 * <code>getClass().getName() + "[x=" + x + ",y=" + y + ']'</code>.
243 * @return a string representation of this object
245 public String
toString()
247 return getClass().getName() + "[x=" + x
+ ",y=" + y
+ ']';