java.lang.Object | |
↳ | java.awt.geom.Area |
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
addition
, subtraction
,
intersection
, and 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:
Area
objects constructed from unclosed paths
are implicitly closed during construction as if those paths
had been filled by the Graphics2D.fill
method.
Area
resembles the path from which it was
constructed only in that it describes the same enclosed
2-dimensional area, but may use entirely different types
and ordering of the path segments to do so.
Area
include:
Area
from an unclosed (open)
Shape
results in a closed outline in the
Area
object.
Area
from a Shape
which encloses no area (even when "closed") produces an
empty Area
. A common example of this issue
is that producing an Area
from a line will
be empty since the line encloses no area. An empty
Area
will iterate no geometry in its
PathIterator
objects.
Shape
may be split into
two (or more) sub-paths each enclosing one of the
non-intersecting portions of the original path.
Area
may take more path segments to
describe the same geometry even when the original
outline is simple and obvious. The analysis that the
Area
class must perform on the path may
not reflect the same concepts of "simple and obvious"
as a human being perceives.
Public Constructors | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Default constructor which creates an empty area.
| |||||||||||
The
Area class creates an area geometry from the
specified Shape object. |
Public Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Adds the shape of the specified
Area to the
shape of this Area . | |||||||||||
Returns an exact copy of this
Area object. | |||||||||||
Tests if a specified
Point2D is inside the boundary
of the Shape . | |||||||||||
Tests if the specified coordinates are inside the boundary of the
Shape . | |||||||||||
Tests if the interior of the
Shape entirely contains
the specified rectangular area. | |||||||||||
Tests if the interior of the
Shape entirely contains the
specified Rectangle2D . | |||||||||||
Creates a new
Area object that contains the same
geometry as this Area transformed by the specified
AffineTransform . | |||||||||||
Tests whether the geometries of the two
Area objects
are equal. | |||||||||||
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. | |||||||||||
Returns a bounding
Rectangle that completely encloses
this Area . | |||||||||||
Returns a high precision bounding
Rectangle2D that
completely encloses this Area . | |||||||||||
Creates a
PathIterator for the outline of this
Area object. | |||||||||||
Creates a
PathIterator for the flattened outline of
this Area object. | |||||||||||
Sets the shape of this
Area to the intersection of
its current shape and the shape of the specified Area . | |||||||||||
Tests if the interior of the
Shape intersects the
interior of a specified rectangular area. | |||||||||||
Tests if the interior of the
Shape intersects the
interior of a specified Rectangle2D . | |||||||||||
Tests whether this
Area object encloses any area. | |||||||||||
Tests whether this
Area consists entirely of
straight edged polygonal geometry. | |||||||||||
Tests whether this
Area is rectangular in shape. | |||||||||||
Tests whether this
Area is comprised of a single
closed subpath. | |||||||||||
Removes all of the geometry from this
Area and
restores it to an empty area. | |||||||||||
Subtracts the shape of the specified
Area from the
shape of this Area . | |||||||||||
Transforms the geometry of this
Area using the specified
AffineTransform . |
[Expand]
Inherited Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
From class
java.lang.Object
| |||||||||||
From interface
java.awt.Shape
|
Default constructor which creates an empty area.
The Area
class creates an area geometry from the
specified 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.
s | the Shape from which the area is constructed |
---|
NullPointerException | if s is null |
---|
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) ################ ################ ################ ############## ############## ################ ############ ############ ################ ########## ########## ################ ######## ######## ################ ###### ###### ###### ###### #### #### #### #### ## ## ## ##
rhs | the Area to be added to the
current shape |
---|
NullPointerException | if rhs is null |
---|
Tests if a specified Point2D
is inside the boundary
of the Shape
.
p | the specified Point2D to be tested |
---|
true
if the specified Point2D
is
inside the boundary of the Shape
;
false
otherwise.Tests if the specified coordinates are inside the boundary of the
Shape
.
x | the specified X coordinate to be tested |
---|---|
y | the specified Y coordinate to be tested |
true
if the specified coordinates are inside
the Shape
boundary; false
otherwise.Tests if the interior of the Shape
entirely contains
the specified rectangular area. All coordinates that lie inside
the rectangular area must lie within the Shape
for the
entire rectanglar area to be considered contained within the
Shape
.
The Shape.contains()
method allows a Shape
implementation to conservatively return false
when:
intersect
method returns true
and
Shape
entirely contains the rectangular area are
prohibitively expensive.
Shapes
this method might
return false
even though the Shape
contains
the rectangular area.
The Area
class performs
more accurate geometric computations than most
Shape
objects and therefore can be used if a more precise
answer is required.x | the X coordinate of the upper-left corner of the specified rectangular area |
---|---|
y | the Y coordinate of the upper-left corner of the specified rectangular area |
w | the width of the specified rectangular area |
h | the height of the specified rectangular area |
true
if the interior of the Shape
entirely contains the specified rectangular area;
false
otherwise or, if the Shape
contains the rectangular area and the
intersects
method returns true
and the containment calculations would be too expensive to
perform.Tests if the interior of the Shape
entirely contains the
specified Rectangle2D
.
The Shape.contains()
method allows a Shape
implementation to conservatively return false
when:
intersect
method returns true
and
Shape
entirely contains the Rectangle2D
are prohibitively expensive.
Shapes
this method might
return false
even though the Shape
contains
the Rectangle2D
.
The Area
class performs
more accurate geometric computations than most
Shape
objects and therefore can be used if a more precise
answer is required.r | The specified Rectangle2D |
---|
true
if the interior of the Shape
entirely contains the Rectangle2D
;
false
otherwise or, if the Shape
contains the Rectangle2D
and the
intersects
method returns true
and the containment calculations would be too expensive to
perform.Creates a new Area
object that contains the same
geometry as this Area
transformed by the specified
AffineTransform
. This Area
object
is unchanged.
t | the specified AffineTransform used to transform
the new Area |
---|
Area
object representing the transformed
geometry.NullPointerException | if t is null |
---|
Tests whether the geometries of the two Area
objects
are equal.
This method will return false if the argument is null.
other | the Area to be compared to this
Area |
---|
true
if the two geometries are equal;
false
otherwise.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) ################ ################ ############## ############## ## ## ############ ############ #### #### ########## ########## ###### ###### ######## ######## ################ ###### ###### ###### ###### #### #### #### #### ## ## ## ##
rhs | the Area to be exclusive ORed with this
Area . |
---|
NullPointerException | if rhs is null |
---|
Returns a bounding 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.
Rectangle
for the
Area
.Returns a high precision bounding 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.
Rectangle2D
for the
Area
.Creates a PathIterator
for the outline of this
Area
object. This Area
object is unchanged.
at | an optional AffineTransform to be applied to
the coordinates as they are returned in the iteration, or
null if untransformed coordinates are desired |
---|
PathIterator
object that returns the
geometry of the outline of this Area
, one
segment at a time.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.
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 |
PathIterator
object that returns the
geometry of the outline of this Area
, one segment
at a time.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) ################ ################ ################ ############## ############## ############ ############ ############ ######## ########## ########## #### ######## ######## ###### ###### #### #### ## ##
rhs | the Area to be intersected with this
Area |
---|
NullPointerException | if rhs is null |
---|
Tests if the interior of the Shape
intersects the
interior of a specified rectangular area.
The rectangular area is considered to intersect the Shape
if any point is contained in both the interior of the
Shape
and the specified rectangular area.
The Shape.intersects()
method allows a Shape
implementation to conservatively return true
when:
Shape
intersect, but
Shapes
this method might
return true
even though the rectangular area does not
intersect the Shape
.
The Area
class performs
more accurate computations of geometric intersection than most
Shape
objects and therefore can be used if a more precise
answer is required.x | the X coordinate of the upper-left corner of the specified rectangular area |
---|---|
y | the Y coordinate of the upper-left corner of the specified rectangular area |
w | the width of the specified rectangular area |
h | the height of the specified rectangular area |
true
if the interior of the Shape
and
the interior of the rectangular area intersect, or are
both highly likely to intersect and intersection calculations
would be too expensive to perform; false
otherwise.Tests if the interior of the Shape
intersects the
interior of a specified Rectangle2D
.
The Shape.intersects()
method allows a Shape
implementation to conservatively return true
when:
Rectangle2D
and the
Shape
intersect, but
Shapes
this method might
return true
even though the Rectangle2D
does not
intersect the Shape
.
The Area
class performs
more accurate computations of geometric intersection than most
Shape
objects and therefore can be used if a more precise
answer is required.r | the specified Rectangle2D |
---|
true
if the interior of the Shape
and
the interior of the specified Rectangle2D
intersect, or are both highly likely to intersect and intersection
calculations would be too expensive to perform; false
otherwise.Tests whether this Area
object encloses any area.
true
if this Area
object
represents an empty area; false
otherwise.Tests whether this Area
consists entirely of
straight edged polygonal geometry.
true
if the geometry of this
Area
consists entirely of line segments;
false
otherwise.Tests whether this Area
is rectangular in shape.
true
if the geometry of this
Area
is rectangular in shape; false
otherwise.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 SEG_MOVETO
segments
that appear in the path.
true
if the Area
is comprised
of a single basic geometry; false
otherwise.Removes all of the geometry from this Area
and
restores it to an empty area.
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) ################ ################ ############## ############## ## ############ ############ #### ########## ########## ###### ######## ######## ######## ###### ###### ###### #### #### #### ## ## ##
rhs | the Area to be subtracted from the
current shape |
---|
NullPointerException | if rhs is null |
---|
Transforms the geometry of this Area
using the specified
AffineTransform
. The geometry is transformed in place, which
permanently changes the enclosed area defined by this object.
t | the transformation used to transform the area |
---|
NullPointerException | if t is null |
---|