This documentation differs from the official API. Jadeite adds extra features to the API including: variable font sizes, constructions examples, placeholders for classes and methods, and auto-generated “See Also” links. Additionally it is missing some items found in standard Javadoc documentation, including: generics type information, “Deprecated” tags and comments, “See Also” links, along with other minor differences. Please send any questions or feedback to bam@cs.cmu.edu.


java.awt.geom
class Area

java.lang.Object extended by java.awt.geom.Area
All Implemented Interfaces:
Shape, Cloneable

Most common ways to construct:

Shape moving = …;

Area movingArea = new Area(moving);

Based on 66 examples

 

Area total = new Area();

Based on 53 examples


public class Area
extends Object
implements Shape, Cloneable

An Area object stores and manipulates a resolution-independent description of an enclosed area of 2-dimensional space. Area objects can be transformed and can perform various Constructive Area Geometry (CAG) operations when combined with other Area objects. The CAG operations include area {@link #add addition}, {@link #subtract subtraction}, {@link #intersect intersection}, and {@link #exclusiveOr exclusive or}. See the linked method documentation for examples of the various operations.

The Area class implements the Shape interface and provides full support for all of its hit-testing and path iteration facilities, but an Area is more specific than a generalized path in a number of ways:

Interesting issues which are not always obvious when using the Area include:


Constructor Summary

          Default constructor which creates an empty area.

          The Area class creates an area geometry from the specified java.awt.Shape object.
 
Method Summary
 void
add(Area rhs)

          Adds the shape of the specified Area to the shape of this Area.
 Object

          Returns an exact copy of this Area object.
 boolean
contains(double x, double y)

          
 boolean
contains(double x, double y, double w, double h)

          
 boolean

          
 boolean

          
 Area

          Creates a new Area object that contains the same geometry as this Area transformed by the specified AffineTransform.
 boolean
equals(Area other)

          Tests whether the geometries of the two Area objects are equal.
 void

          Sets the shape of this Area to be the combined area of its current shape and the shape of the specified Area, minus their intersection.
 Rectangle

          Returns a bounding java.awt.Rectangle that completely encloses this Area.
 Rectangle2D

          Returns a high precision bounding java.awt.geom.Rectangle2D that completely encloses this Area.
 PathIterator

          Creates a java.awt.geom.PathIterator for the outline of this Area object.
 PathIterator
getPathIterator(AffineTransform at, double flatness)

          Creates a PathIterator for the flattened outline of this Area object.
 void

          Sets the shape of this Area to the intersection of its current shape and the shape of the specified Area.
 boolean
intersects(double x, double y, double w, double h)

          
 boolean

          
 boolean

          Tests whether this Area object encloses any area.
 boolean

          Tests whether this Area consists entirely of straight edged polygonal geometry.
 boolean

          Tests whether this Area is rectangular in shape.
 boolean

          Tests whether this Area is comprised of a single closed subpath.
 void

          Removes all of the geometry from this Area and restores it to an empty area.
 void

          Subtracts the shape of the specified Area from the shape of this Area.
 void

          Transforms the geometry of this Area using the specified java.awt.geom.AffineTransform.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Area

public Area()
Default constructor which creates an empty area.


Area

public Area(Shape s)
The Area class creates an area geometry from the specified {@link Shape} object. The geometry is explicitly closed, if the Shape is not already closed. The fill rule (even-odd or winding) specified by the geometry of the Shape is used to determine the resulting enclosed area.

Parameters:
s - the Shape from which the area is constructed
Method Detail

add

public void add(Area rhs)
Adds the shape of the specified Area to the shape of this Area. The resulting shape of this Area will include the union of both shapes, or all areas that were contained in either this or the specified Area.
     // Example:
     Area a1 = new Area([triangle 0,0 => 8,0 => 0,8]);
     Area a2 = new Area([triangle 0,0 => 8,0 => 8,8]);
     a1.add(a2);

        a1(before)     +         a2         =     a1(after)

     ################     ################     ################
     ##############         ##############     ################
     ############             ############     ################
     ##########                 ##########     ################
     ########                     ########     ################
     ######                         ######     ######    ######
     ####                             ####     ####        ####
     ##                                 ##     ##            ##
 

Parameters:
rhs - the Area to be added to the current shape

clone

public Object clone()
Returns an exact copy of this Area object.

Overrides:
clone in class Object
Returns:
Created clone object

contains

public boolean contains(double x,
                        double y)
{@inheritDoc}

Parameters:
x
y

contains

public boolean contains(double x,
                        double y,
                        double w,
                        double h)
{@inheritDoc}

Parameters:
x
y
w
h

contains

public boolean contains(Point2D p)
{@inheritDoc}

Parameters:
p

contains

public boolean contains(Rectangle2D r)
{@inheritDoc}

Parameters:
r

createTransformedArea

public Area createTransformedArea(AffineTransform t)
Creates a new Area object that contains the same geometry as this Area transformed by the specified AffineTransform. This Area object is unchanged.

Parameters:
t - the specified AffineTransform used to transform the new Area
Returns:
a new Area object representing the transformed geometry.

equals

public boolean equals(Area other)
Tests whether the geometries of the two Area objects are equal. This method will return false if the argument is null.

Parameters:
other - the Area to be compared to this Area
Returns:
true if the two geometries are equal; false otherwise.

exclusiveOr

public void exclusiveOr(Area rhs)
Sets the shape of this Area to be the combined area of its current shape and the shape of the specified Area, minus their intersection. The resulting shape of this Area will include only areas that were contained in either this Area or in the specified Area, but not in both.
     // Example:
     Area a1 = new Area([triangle 0,0 => 8,0 => 0,8]);
     Area a2 = new Area([triangle 0,0 => 8,0 => 8,8]);
     a1.exclusiveOr(a2);

        a1(before)    xor        a2         =     a1(after)

     ################     ################
     ##############         ##############     ##            ##
     ############             ############     ####        ####
     ##########                 ##########     ######    ######
     ########                     ########     ################
     ######                         ######     ######    ######
     ####                             ####     ####        ####
     ##                                 ##     ##            ##
 

Parameters:
rhs - the Area to be exclusive ORed with this Area.

getBounds

public Rectangle getBounds()
Returns a bounding {@link Rectangle} that completely encloses this Area.

The Area class will attempt to return the tightest bounding box possible for the Shape. The bounding box will not be padded to include the control points of curves in the outline of the Shape, but should tightly fit the actual geometry of the outline itself. Since the returned object represents the bounding box with integers, the bounding box can only be as tight as the nearest integer coordinates that encompass the geometry of the Shape.

Returns:
the bounding Rectangle for the Area.

getBounds2D

public Rectangle2D getBounds2D()
Returns a high precision bounding {@link Rectangle2D} that completely encloses this Area.

The Area class will attempt to return the tightest bounding box possible for the Shape. The bounding box will not be padded to include the control points of curves in the outline of the Shape, but should tightly fit the actual geometry of the outline itself.

Returns:
the bounding Rectangle2D for the Area.

getPathIterator

public PathIterator getPathIterator(AffineTransform at)
Creates a {@link PathIterator} for the outline of this Area object. This Area object is unchanged.

Parameters:
at - an optional AffineTransform to be applied to the coordinates as they are returned in the iteration, or null if untransformed coordinates are desired
Returns:
the PathIterator object that returns the geometry of the outline of this Area, one segment at a time.

getPathIterator

public PathIterator getPathIterator(AffineTransform at,
                                    double flatness)
Creates a PathIterator for the flattened outline of this Area object. Only uncurved path segments represented by the SEG_MOVETO, SEG_LINETO, and SEG_CLOSE point types are returned by the iterator. This Area object is unchanged.

Parameters:
at - an optional AffineTransform to be applied to the coordinates as they are returned in the iteration, or null if untransformed coordinates are desired
flatness - the maximum amount that the control points for a given curve can vary from colinear before a subdivided curve is replaced by a straight line connecting the end points
Returns:
the PathIterator object that returns the geometry of the outline of this Area, one segment at a time.

intersect

public void intersect(Area rhs)
Sets the shape of this Area to the intersection of its current shape and the shape of the specified Area. The resulting shape of this Area will include only areas that were contained in both this Area and also in the specified Area.
     // Example:
     Area a1 = new Area([triangle 0,0 => 8,0 => 0,8]);
     Area a2 = new Area([triangle 0,0 => 8,0 => 8,8]);
     a1.intersect(a2);

      a1(before)   intersect     a2         =     a1(after)

     ################     ################     ################
     ##############         ##############       ############
     ############             ############         ########
     ##########                 ##########           ####
     ########                     ########
     ######                         ######
     ####                             ####
     ##                                 ##
 

Parameters:
rhs - the Area to be intersected with this Area

intersects

public boolean intersects(double x,
                          double y,
                          double w,
                          double h)
{@inheritDoc}

Parameters:
x
y
w
h

intersects

public boolean intersects(Rectangle2D r)
{@inheritDoc}

Parameters:
r

isEmpty

public boolean isEmpty()
Tests whether this Area object encloses any area.

Returns:
true if this Area object represents an empty area; false otherwise.

isPolygonal

public boolean isPolygonal()
Tests whether this Area consists entirely of straight edged polygonal geometry.

Returns:
true if the geometry of this Area consists entirely of line segments; false otherwise.

isRectangular

public boolean isRectangular()
Tests whether this Area is rectangular in shape.

Returns:
true if the geometry of this Area is rectangular in shape; false otherwise.

isSingular

public boolean isSingular()
Tests whether this Area is comprised of a single closed subpath. This method returns true if the path contains 0 or 1 subpaths, or false if the path contains more than 1 subpath. The subpaths are counted by the number of {@link PathIterator#SEG_MOVETO SEG_MOVETO} segments that appear in the path.

Returns:
true if the Area is comprised of a single basic geometry; false otherwise.

reset

public void reset()
Removes all of the geometry from this Area and restores it to an empty area.


subtract

public void subtract(Area rhs)
Subtracts the shape of the specified Area from the shape of this Area. The resulting shape of this Area will include areas that were contained only in this Area and not in the specified Area.
     // Example:
     Area a1 = new Area([triangle 0,0 => 8,0 => 0,8]);
     Area a2 = new Area([triangle 0,0 => 8,0 => 8,8]);
     a1.subtract(a2);

        a1(before)     -         a2         =     a1(after)

     ################     ################
     ##############         ##############     ##
     ############             ############     ####
     ##########                 ##########     ######
     ########                     ########     ########
     ######                         ######     ######
     ####                             ####     ####
     ##                                 ##     ##
 

Parameters:
rhs - the Area to be subtracted from the current shape

transform

public void transform(AffineTransform t)
Transforms the geometry of this Area using the specified {@link AffineTransform}. The geometry is transformed in place, which permanently changes the enclosed area defined by this object.

Parameters:
t - the transformation used to transform the area


This documentation differs from the official API. Jadeite adds extra features to the API including: variable font sizes, constructions examples, placeholders for classes and methods, and auto-generated “See Also” links. Additionally it is missing some items found in standard Javadoc documentation, including: generics type information, “Deprecated” tags and comments, “See Also” links, along with other minor differences. Please send any questions or feedback to bam@cs.cmu.edu.
This page displays the Jadeite version of the documention, which is derived from the offical documentation that contains this copyright notice:
Copyright 2008 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.
The official Sun™ documentation can be found here at http://java.sun.com/javase/6/docs/api/.