java.awt

Class Rectangle

java.lang.Object

java.awt.Rectangle

All Implemented Interfaces:

Shape, Serializable, Cloneable

public class Rectangle
extends Object
implements Shape, Serializable, Cloneable

A Rectangle specifies an area in a coordinate space that is enclosed by the Rectangle object's top-left point (x, y) in the coordinate space, its width, and its height.

A Rectangle object's width and height are public fields. The constructors that create a Rectangle, and the methods that can modify one, do not prevent setting a negative value for width or height.

A Rectangle whose width or height is negative is considered empty. If the Rectangle is empty, then the isEmpty method returns true. No point can be contained by or inside an empty Rectangle. The values of width and height, however, are still valid. An empty Rectangle still has a location in the coordinate space, and methods that change its size or location remain valid. The behavior of methods that operate on more than one Rectangle is undefined if any of the participating Rectangle objects has a negative width or height. These methods include intersects, intersection, and union.

Since:

JDK1.0

Version:

1.65, 01/23/03

Author:

Sami Shaio

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
int	height The height of the Rectangle.
int	width The width of the Rectangle.
int	x The x coordinate of the Rectangle.
int	y The y coordinate of the Rectangle.

Constructor Summary

Constructors

Constructor and Description
Rectangle() Constructs a new Rectangle whose top-left corner is at (0, 0) in the coordinate space, and whose width and height are both zero.
Rectangle(Dimension d) Constructs a new Rectangle whose top left corner is (0, 0) and whose width and height are specified by the Dimension argument.
Rectangle(int width, int height) Constructs a new Rectangle whose top-left corner is at (0, 0) in the coordinate space, and whose width and height are specified by the arguments of the same name.
Rectangle(int x, int y, int width, int height) Constructs a new Rectangle whose top-left corner is specified as (x, y) and whose width and height are specified by the arguments of the same name.
Rectangle(Point p) Constructs a new Rectangle whose top-left corner is the specified Point, and whose width and height are both zero.
Rectangle(Point p, Dimension d) Constructs a new Rectangle whose top-left corner is specified by the Point argument, and whose width and height are specified by the Dimension argument.
Rectangle(Rectangle r) Constructs a new Rectangle, initialized to match the values of the specified Rectangle.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(int newx, int newy) Adds a point, specified by the integer arguments newx and newy, to this Rectangle.
void	add(Point pt) Adds the specified Point to this Rectangle.
void	add(Rectangle r) Adds a Rectangle to this Rectangle.
Object	clone() Creates a new object of the same class and with the same contents as this object.
boolean	contains(int x, int y) Checks whether or not this Rectangle contains the point at the specified location (x, y).
boolean	contains(int X, int Y, int W, int H) Checks whether this Rectangle entirely contains the Rectangle at the specified location (X, Y) with the specified dimensions (W, H).
boolean	contains(Point p) Checks whether or not this Rectangle contains the specified Point.
boolean	contains(Rectangle r) Checks whether or not this Rectangle entirely contains the specified Rectangle.
boolean	equals(Object obj) Checks whether two rectangles are equal.
Rectangle	getBounds() Gets the bounding Rectangle of this Rectangle.
Point	getLocation() Returns the location of this Rectangle.
Dimension	getSize() Gets the size of this Rectangle, represented by the returned Dimension.
void	grow(int h, int v) Resizes the Rectangle both horizontally and vertically.
int	hashCode() Returns the hashcode for this Rectangle.
Rectangle	intersection(Rectangle r) Computes the intersection of this Rectangle with the specified Rectangle.
boolean	intersects(Rectangle r) Determines whether or not this Rectangle and the specified Rectangle intersect.
boolean	isEmpty() Determines whether or not this Rectangle is empty.
void	setBounds(int x, int y, int width, int height) Sets the bounding Rectangle of this Rectangle to the specified x, y, width, and height.
void	setBounds(Rectangle r) Sets the bounding Rectangle of this Rectangle to match the specified Rectangle.
void	setLocation(int x, int y) Moves this Rectangle to the specified location.
void	setLocation(Point p) Moves this Rectangle to the specified location.
void	setSize(Dimension d) Sets the size of this Rectangle to match the specified Dimension.
void	setSize(int width, int height) Sets the size of this Rectangle to the specified width and height.
String	toString() Returns a String representing this Rectangle and its values.
void	translate(int x, int y) Translates this Rectangle the indicated distance, to the right along the x coordinate axis, and downward along the y coordinate axis.
Rectangle	union(Rectangle r) Computes the union of this Rectangle with the specified Rectangle.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

x

public int x

The x coordinate of the Rectangle.

See Also:

setLocation(int, int), getLocation()

y

public int y

The y coordinate of the Rectangle.

See Also:

setLocation(int, int), getLocation()

width

public int width

The width of the Rectangle.

Since:

JDK1.0.

See Also:

setSize(int, int), getSize()

height

public int height

The height of the Rectangle.

See Also:

setSize(int, int), getSize()

Constructor Detail

Rectangle

public Rectangle()

Constructs a new Rectangle whose top-left corner is at (0, 0) in the coordinate space, and whose width and height are both zero.

Rectangle

public Rectangle(Rectangle r)

Constructs a new Rectangle, initialized to match the values of the specified Rectangle.

Parameters:

r - the Rectangle from which to copy initial values to a newly constructed Rectangle

Since:

JDK1.1

Rectangle

public Rectangle(int x,
         int y,
         int width,
         int height)

Constructs a new Rectangle whose top-left corner is specified as (x, y) and whose width and height are specified by the arguments of the same name.

Parameters:

x - the specified x coordinate

y - the specified y coordinate

width - the width of the Rectangle

height - the height of the Rectangle

Rectangle

public Rectangle(int width,
         int height)

Constructs a new Rectangle whose top-left corner is at (0, 0) in the coordinate space, and whose width and height are specified by the arguments of the same name.

Parameters:

width - the width of the Rectangle

height - the height of the Rectangle

Rectangle

public Rectangle(Point p,
         Dimension d)

Constructs a new Rectangle whose top-left corner is specified by the Point argument, and whose width and height are specified by the Dimension argument.

Parameters:

p - a Point that is the top-left corner of the Rectangle

d - a Dimension, representing the width and height of the Rectangle

Rectangle

public Rectangle(Point p)

Constructs a new Rectangle whose top-left corner is the specified Point, and whose width and height are both zero.

Parameters:

p - a Point that is the top left corner of the Rectangle

Rectangle

public Rectangle(Dimension d)

Constructs a new Rectangle whose top left corner is (0, 0) and whose width and height are specified by the Dimension argument.

Parameters:

d - a Dimension, specifying width and height

Method Detail

getBounds

public Rectangle getBounds()

Gets the bounding Rectangle of this Rectangle.

This method is included for completeness, to parallel the getBounds method of Component.

Specified by:

getBounds in interface Shape

Returns:

a new Rectangle, equal to the bounding Rectangle for this Rectangle.

Since:

JDK1.1

See Also:

Component.getBounds(), setBounds(Rectangle), setBounds(int, int, int, int)

setBounds

public void setBounds(Rectangle r)

Sets the bounding Rectangle of this Rectangle to match the specified Rectangle.

This method is included for completeness, to parallel the setBounds method of Component.

Parameters:

r - the specified Rectangle

Since:

JDK1.1

See Also:

getBounds(), Component.setBounds(java.awt.Rectangle)

setBounds

public void setBounds(int x,
             int y,
             int width,
             int height)

Sets the bounding Rectangle of this Rectangle to the specified x, y, width, and height.

This method is included for completeness, to parallel the setBounds method of Component.

Parameters:

x - the new x coordinate for the top-left corner of this Rectangle

y - the new y coordinate for the top-left corner of this Rectangle

width - the new width for this Rectangle

height - the new height for this Rectangle

Since:

JDK1.1

See Also:

getBounds(), Component.setBounds(int, int, int, int)

getLocation

public Point getLocation()

Returns the location of this Rectangle.

This method is included for completeness, to parallel the getLocation method of Component.

Returns:

the Point that is the top-left corner of this Rectangle.

Since:

JDK1.1

See Also:

Component.getLocation(), setLocation(Point), setLocation(int, int)

setLocation

public void setLocation(Point p)

Moves this Rectangle to the specified location.

This method is included for completeness, to parallel the setLocation method of Component.

Parameters:

p - the Point specifying the new location for this Rectangle

Since:

JDK1.1

See Also:

Component.setLocation(java.awt.Point), getLocation()

setLocation

public void setLocation(int x,
               int y)

Moves this Rectangle to the specified location.

This method is included for completeness, to parallel the setLocation method of Component.

Parameters:

x - the x coordinate of the new location

y - the y coordinate of the new location

Since:

JDK1.1

See Also:

getLocation(), Component.setLocation(int, int)

translate

public void translate(int x,
             int y)

Translates this Rectangle the indicated distance, to the right along the x coordinate axis, and downward along the y coordinate axis.

Parameters:

x - the distance to move this Rectangle along the x axis

y - the distance to move this Rectangle along the y axis

See Also:

setLocation(int, int), setLocation(java.awt.Point)

getSize

public Dimension getSize()

Gets the size of this Rectangle, represented by the returned Dimension.

This method is included for completeness, to parallel the getSize method of Component.

Returns:

a Dimension, representing the size of this Rectangle.

Since:

JDK1.1

See Also:

Component.getSize(), setSize(Dimension), setSize(int, int)

setSize

public void setSize(Dimension d)

Sets the size of this Rectangle to match the specified Dimension.

This method is included for completeness, to parallel the setSize method of Component.

Parameters:

d - the new size for the Dimension object

Since:

JDK1.1

See Also:

Component.setSize(java.awt.Dimension), getSize()

setSize

public void setSize(int width,
           int height)

Sets the size of this Rectangle to the specified width and height.

This method is included for completeness, to parallel the setSize method of Component.

Parameters:

width - the new width for this Rectangle

height - the new height for this Rectangle

Since:

JDK1.1

See Also:

Component.setSize(int, int), getSize()

contains

public boolean contains(Point p)

Checks whether or not this Rectangle contains the specified Point.

Parameters:

p - the Point to test

Returns:

true if the Point (x, y) is inside this Rectangle; false otherwise.

Since:

JDK1.1

contains

public boolean contains(int x,
               int y)

Checks whether or not this Rectangle contains the point at the specified location (x, y).

Parameters:

x - the specified x coordinate

y - the specified y coordinate

Returns:

true if the point (x, y) is inside this Rectangle; false otherwise.

Since:

JDK1.1

contains

public boolean contains(Rectangle r)

Checks whether or not this Rectangle entirely contains the specified Rectangle.

Parameters:

r - the specified Rectangle

Returns:

true if the Rectangle is contained entirely inside this Rectangle; false otherwise.

Since:

JDK1.1

contains

public boolean contains(int X,
               int Y,
               int W,
               int H)

Checks whether this Rectangle entirely contains the Rectangle at the specified location (X, Y) with the specified dimensions (W, H).

Parameters:

X - the specified x coordinate

Y - the specified y coordinate

W - the width of the Rectangle

H - the height of the Rectangle

Returns:

true if the Rectangle specified by (X, Y, W, H) is entirely enclosed inside this Rectangle; false otherwise.

Since:

JDK1.1

intersects

public boolean intersects(Rectangle r)

Determines whether or not this Rectangle and the specified Rectangle intersect. Two rectangles intersect if their intersection is nonempty.

Parameters:

r - the specified Rectangle

Returns:

true if the specified Rectangle and this Rectangle intersect; false otherwise.

intersection

public Rectangle intersection(Rectangle r)

Computes the intersection of this Rectangle with the specified Rectangle. Returns a new Rectangle that represents the intersection of the two rectangles. If the two rectangles do not intersect, the result will be an empty rectangle.

Parameters:

r - the specified Rectangle

Returns:

the largest Rectangle contained in both the specified Rectangle and in this Rectangle; or if the rectangles do not intersect, an empty rectangle.

union

public Rectangle union(Rectangle r)

Computes the union of this Rectangle with the specified Rectangle. Returns a new Rectangle that represents the union of the two rectangles

Parameters:

r - the specified Rectangle

Returns:

the smallest Rectangle containing both the specified Rectangle and this Rectangle.

add

public void add(int newx,
       int newy)

Adds a point, specified by the integer arguments newx and newy, to this Rectangle. The resulting Rectangle is the smallest Rectangle that contains both the original Rectangle and the specified point.

After adding a point, a call to contains with the added point as an argument does not necessarily return true. The contains method does not return true for points on the right or bottom edges of a Rectangle. Therefore, if the added point falls on the right or bottom edge of the enlarged Rectangle, contains returns false for that point.

Parameters:

newx - the x coordinate of the new point

newy - the y coordinate of the new point

add

public void add(Point pt)

Adds the specified Point to this Rectangle. The resulting Rectangle is the smallest Rectangle that contains both the original Rectangle and the specified Point.

After adding a Point, a call to contains with the added Point as an argument does not necessarily return true. The contains method does not return true for points on the right or bottom edges of a Rectangle. Therefore if the added Point falls on the right or bottom edge of the enlarged Rectangle, contains returns false for that Point.

Parameters:

pt - the new Point to add to this Rectangle

add

public void add(Rectangle r)

Adds a Rectangle to this Rectangle. The resulting Rectangle is the union of the two rectangles.

Parameters:

r - the specified Rectangle

grow

public void grow(int h,
        int v)

Resizes the Rectangle both horizontally and vertically.

This method modifies the Rectangle so that it is h units larger on both the left and right side, and v units larger at both the top and bottom.

The new Rectangle has (x - h, y - v) as its top-left corner, a width of width + 2h, and a height of height + 2v.

If negative values are supplied for h and v, the size of the Rectangle decreases accordingly. The grow method does not check whether the resulting values of width and height are non-negative.

Parameters:

h - the horizontal expansion

v - the vertical expansion

isEmpty

public boolean isEmpty()

Determines whether or not this Rectangle is empty. A Rectangle is empty if its width or its height is less than or equal to zero.

Returns:

true if this Rectangle is empty; false otherwise.

equals

public boolean equals(Object obj)

Checks whether two rectangles are equal.

The result is true if and only if the argument is not null and is a Rectangle object that has the same top-left corner, width, and height as this Rectangle.

Overrides:

equals in class Object

Parameters:

obj - the Object to compare with this Rectangle

Returns:

true if the objects are equal; false otherwise.

See Also:

Object.hashCode(), Hashtable

toString

public String toString()

Returns a String representing this Rectangle and its values.

Overrides:

toString in class Object

Returns:

a String representing this Rectangle object's coordinate and size values.

clone

public Object clone()

Creates a new object of the same class and with the same contents as this object.

Overrides:

clone in class Object

Returns:

a clone of this instance.

Throws:

OutOfMemoryError - if there is not enough memory.

Since:

1.2

See Also:

Cloneable

hashCode

public int hashCode()

Returns the hashcode for this Rectangle.

Overrides:

hashCode in class Object

Returns:

a hash code for this Rectangle.

See Also:

Object.equals(java.lang.Object), Hashtable