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Point (Java Platform SE 6) - JDK 5 Documentation v6.0, Java 2 SDK 英文文档


Java™ Platform
Standard Ed. 6

java.awt
Class Point

java.lang.Object
  extended by java.awt.geom.Point2D
      extended by java.awt.Point
All Implemented Interfaces:
Serializable, Cloneable

public class Point
extends Point2D
implements Serializable

A point representing a location in (x,y) coordinate space, specified in integer precision.

Since:
1.0
See Also:
Serialized Form

Nested Class Summary
 
Nested classes/interfaces inherited from class java.awt.geom.Point2D
Point2D.Double, Point2D.Float
 
Field Summary
 int x
          The X coordinate of this Point.
 int y
          The Y coordinate of this Point.
 
Constructor Summary
Point()
          Constructs and initializes a point at the origin (0, 0) of the coordinate space.
Point(int x, int y)
          Constructs and initializes a point at the specified (x,y) location in the coordinate space.
Point(Point p)
          Constructs and initializes a point with the same location as the specified Point object.
 
Method Summary
 boolean equals(Object obj)
          Determines whether or not two points are equal.
 Point getLocation()
          Returns the location of this point.
 double getX()
          Returns the X coordinate of this Point2D in double precision.
 double getY()
          Returns the Y coordinate of this Point2D in double precision.
 void move(int x, int y)
          Moves this point to the specified location in the (x,y) coordinate plane.
 void setLocation(double x, double y)
          Sets the location of this point to the specified double coordinates.
 void setLocation(int x, int y)
          Changes the point to have the specified location.
 void setLocation(Point p)
          Sets the location of the point to the specified location.
 String toString()
          Returns a string representation of this point and its location in the (x,y) coordinate space.
 void translate(int dx, int dy)
          Translates this point, at location (x,y), by dx along the x axis and dy along the y axis so that it now represents the point (x+dx,y+dy).
 
Methods inherited from class java.awt.geom.Point2D
clone, distance, distance, distance, distanceSq, distanceSq, distanceSq, hashCode, setLocation
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

x

public int x
The X coordinate of this Point. If no X coordinate is set it will default to 0.

Since:
1.0
See Also:
getLocation(), move(int, int)

y

public int y
The Y coordinate of this Point. If no Y coordinate is set it will default to 0.

Since:
1.0
See Also:
getLocation(), move(int, int)
Constructor Detail

Point

public Point()
Constructs and initializes a point at the origin (0, 0) of the coordinate space.

Since:
1.1

Point

public Point(Point p)
Constructs and initializes a point with the same location as the specified Point object.

Parameters:
p - a point
Since:
1.1

Point

public Point(int x,
             int y)
Constructs and initializes a point at the specified (x,y) location in the coordinate space.

Parameters:
x - the X coordinate of the newly constructed Point
y - the Y coordinate of the newly constructed Point
Since:
1.0
Method Detail

getX

public double getX()
Returns the X coordinate of this Point2D in double precision.

Specified by:
getX in class Point2D
Returns:
the X coordinate of this Point2D.
Since:
1.2

getY

public double getY()
Returns the Y coordinate of this Point2D in double precision.

Specified by:
getY in class Point2D
Returns:
the Y coordinate of this Point2D.
Since:
1.2

getLocation

public Point getLocation()
Returns the location of this point. This method is included for completeness, to parallel the getLocation method of Component.

Returns:
a copy of this point, at the same location
Since:
1.1
See Also:
Component.getLocation(), setLocation(java.awt.Point), setLocation(int, int)

setLocation

public void setLocation(Point p)
Sets the location of the point to the specified location. This method is included for completeness, to parallel the setLocation method of Component.

Parameters:
p - a point, the new location for this point
Since:
1.1
See Also:
Component.setLocation(java.awt.Point), getLocation()

setLocation

public void setLocation(int x,
                        int y)
Changes the point to have the specified location.

This method is included for completeness, to parallel the setLocation method of Component. Its behavior is identical with move(int, int).

Parameters:
x - the X coordinate of the new location
y - the Y coordinate of the new location
Since:
1.1
See Also:
Component.setLocation(int, int), getLocation(), move(int, int)

setLocation

public void setLocation(double x,
                        double y)
Sets the location of this point to the specified double coordinates. The double values will be rounded to integer values. Any number smaller than Integer.MIN_VALUE will be reset to MIN_VALUE, and any number larger than Integer.MAX_VALUE will be reset to MAX_VALUE.

Specified by:
setLocation in class Point2D
Parameters:
x - the X coordinate of the new location
y - the Y coordinate of the new location
See Also:
getLocation()

move

public void move(int x,
                 int y)
Moves this point to the specified location in the (x,y) coordinate plane. This method is identical with setLocation(int, int).

Parameters:
x - the X coordinate of the new location
y - the Y coordinate of the new location
See Also:
Component.setLocation(int, int)

translate

public void translate(int dx,
                      int dy)
Translates this point, at location (x,y), by dx along the x axis and dy along the y axis so that it now represents the point (x+dx,y+dy).

Parameters:
dx - the distance to move this point along the X axis
dy - the distance to move this point along the Y axis

equals

public boolean equals(Object obj)
Determines whether or not two points are equal. Two instances of Point2D are equal if the values of their x and y member fields, representing their position in the coordinate space, are the same.

Overrides:
equals in class Point2D
Parameters:
obj - an object to be compared with this Point2D
Returns:
true if the object to be compared is an instance of Point2D and has the same values; false otherwise.
See Also:
Object.hashCode(), Hashtable

toString

public String toString()
Returns a string representation of this point and its location in the (x,y) coordinate space. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be null.

Overrides:
toString in class Object
Returns:
a string representation of this point

Java™ Platform
Standard Ed. 6

Submit a bug or feature
For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright 2006 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.