Point


1   /*
2    * @(#)Point.java   1.38 03/12/19
3    *
4    * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
5    * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6    */
7   
8   package java.awt;
9   
10  import java.awt.geom.Point2D  ;
11  
12  /**
13   * A point representing a location in (x, y) coordinate space, specified
14   * in integer precision.
15   *
16   * @version     1.38, 12/19/03
17   * @author  Sami Shaio
18   * @since       JDK1.0
19   */
20  public class Point extends Point2D   implements java.io.Serializable   {
21      /**
22       * The <i>x</i> coordinate.
23       * If no <i>x</i> coordinate is set it will default to 0.
24       *
25       * @serial
26       * @see #getLocation()
27       * @see #move(int, int)
28       */
29      public int x;
30  
31      /**
32       * The <i>y</i> coordinate. 
33       * If no <i>y</i> coordinate is set it will default to 0.
34       *
35       * @serial
36       * @see #getLocation()
37       * @see #move(int, int)
38       */
39      public int y;
40  
41      /*
42       * JDK 1.1 serialVersionUID 
43       */
44      private static final long serialVersionUID = -5276940640259749850L;
45  
46      /**
47       * Constructs and initializes a point at the origin 
48       * (0,&nbsp;0) of the coordinate space. 
49       * @since       JDK1.1
50       */
51      public Point() {
52      this(0, 0);
53      }
54  
55      /**
56       * Constructs and initializes a point with the same location as
57       * the specified <code>Point</code> object.
58       * @param       p a point
59       * @since       JDK1.1
60       */
61      public Point(Point   p) {
62      this(p.x, p.y);
63      }
64  
65      /**
66       * Constructs and initializes a point at the specified 
67       * (<i>x</i>,&nbsp;<i>y</i>) location in the coordinate space. 
68       * @param       x   the <i>x</i> coordinate
69       * @param       y   the <i>y</i> coordinate
70       */
71      public Point(int x, int y) {
72      this.x = x;
73      this.y = y;
74      }
75  
76      /**
77       * Returns the X coordinate of the point in double precision.
78       * @return the X coordinate of the point in double precision
79       */
80      public double getX() {
81      return x;
82      }
83  
84      /**
85       * Returns the Y coordinate of the point in double precision.
86       * @return the Y coordinate of the point in double precision
87       */
88      public double getY() {
89      return y;
90      }
91  
92      /**
93       * Returns the location of this point.
94       * This method is included for completeness, to parallel the
95       * <code>getLocation</code> method of <code>Component</code>.
96       * @return      a copy of this point, at the same location
97       * @see         java.awt.Component#getLocation
98       * @see         java.awt.Point#setLocation(java.awt.Point)
99       * @see         java.awt.Point#setLocation(int, int)
100      * @since       JDK1.1
101      */
102     public Point   getLocation() {
103     return new Point  (x, y);
104     }   
105 
106     /**
107      * Sets the location of the point to the specified location.
108      * This method is included for completeness, to parallel the
109      * <code>setLocation</code> method of <code>Component</code>.
110      * @param       p  a point, the new location for this point
111      * @see         java.awt.Component#setLocation(java.awt.Point)
112      * @see         java.awt.Point#getLocation
113      * @since       JDK1.1
114      */
115     public void setLocation(Point   p) {
116     setLocation(p.x, p.y);
117     }   
118 
119     /**
120      * Changes the point to have the specified location.
121      * <p>
122      * This method is included for completeness, to parallel the
123      * <code>setLocation</code> method of <code>Component</code>.
124      * Its behavior is identical with <code>move(int,&nbsp;int)</code>.
125      * @param       x  the <i>x</i> coordinate of the new location
126      * @param       y  the <i>y</i> coordinate of the new location
127      * @see         java.awt.Component#setLocation(int, int)
128      * @see         java.awt.Point#getLocation
129      * @see         java.awt.Point#move(int, int)
130      * @since       JDK1.1
131      */
132     public void setLocation(int x, int y) {
133     move(x, y);
134     }   
135 
136     /**
137      * Sets the location of this point to the specified double coordinates.
138      * The double values will be rounded to integer values.
139      * Any number smaller than <code>Integer.MIN_VALUE</code>
140      * will be reset to <code>MIN_VALUE</code>, and any number
141      * larger than <code>Integer.MAX_VALUE</code> will be
142      * reset to <code>MAX_VALUE</code>.
143      *
144      * @param x the <i>x</i> coordinate of the new location
145      * @param y the <i>y</i> coordinate of the new location
146      * @see #getLocation
147      */
148     public void setLocation(double x, double y) {
149     this.x = (int) Math.floor(x+0.5);
150     this.y = (int) Math.floor(y+0.5);
151     }
152 
153     /**
154      * Moves this point to the specified location in the 
155      * (<i>x</i>,&nbsp;<i>y</i>) coordinate plane. This method
156      * is identical with <code>setLocation(int,&nbsp;int)</code>.
157      * @param       x  the <i>x</i> coordinate of the new location
158      * @param       y  the <i>y</i> coordinate of the new location
159      * @see         java.awt.Component#setLocation(int, int)
160      */
161     public void move(int x, int y) {
162     this.x = x;
163     this.y = y;
164     }   
165 
166     /**
167      * Translates this point, at location (<i>x</i>,&nbsp;<i>y</i>), 
168      * by <code>dx</code> along the <i>x</i> axis and <code>dy</code> 
169      * along the <i>y</i> axis so that it now represents the point 
170      * (<code>x</code>&nbsp;<code>+</code>&nbsp;<code>dx</code>, 
171      * <code>y</code>&nbsp;<code>+</code>&nbsp;<code>dy</code>). 
172      * @param       dx   the distance to move this point 
173      *                            along the <i>x</i> axis
174      * @param       dy    the distance to move this point 
175      *                            along the <i>y</i> axis
176      */
177     public void translate(int dx, int dy) {
178     this.x += dx;
179     this.y += dy;
180     }   
181 
182     /**
183      * Determines whether or not two points are equal. Two instances of
184      * <code>Point2D</code> are equal if the values of their 
185      * <code>x</code> and <code>y</code> member fields, representing
186      * their position in the coordinate space, are the same.
187      * @param obj an object to be compared with this <code>Point2D</code>
188      * @return <code>true</code> if the object to be compared is
189      *         an instance of <code>Point2D</code> and has
190      *         the same values; <code>false</code> otherwise.
191      */
192     public boolean equals(Object   obj) {
193     if (obj instanceof Point  ) {
194         Point   pt = (Point  )obj;
195         return (x == pt.x) && (y == pt.y);
196     }
197     return super.equals(obj);
198     }
199 
200     /**
201      * Returns a string representation of this point and its location 
202      * in the (<i>x</i>,&nbsp;<i>y</i>) coordinate space. This method is 
203      * intended to be used only for debugging purposes, and the content 
204      * and format of the returned string may vary between implementations. 
205      * The returned string may be empty but may not be <code>null</code>.
206      * 
207      * @return  a string representation of this point
208      */
209     public String   toString() {
210     return getClass().getName() + "[x=" + x + ",y=" + y + "]";
211     }
212 }
213
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags