Interface Shape
-
- All Known Implementing Classes:
- Arc2D, Arc2D.Double, Arc2D.Float, Area, BasicTextUI.BasicCaret, CubicCurve2D, CubicCurve2D.Double, CubicCurve2D.Float, DefaultCaret, Ellipse2D, Ellipse2D.Double, Ellipse2D.Float, GeneralPath, Line2D, Line2D.Double, Line2D.Float, Path2D, Path2D.Double, Path2D.Float, Polygon, QuadCurve2D, QuadCurve2D.Double, QuadCurve2D.Float, Rectangle, Rectangle2D, Rectangle2D.Double, Rectangle2D.Float, RectangularShape, RoundRectangle2D, RoundRectangle2D.Double, RoundRectangle2D.Float
public interface Shape
TheShape
interface provides definitions for objects that represent some form of geometric shape. TheShape
is described by aPathIterator
object, which can express the outline of theShape
as well as a rule for determining how the outline divides the 2D plane into interior and exterior points. EachShape
object provides callbacks to get the bounding box of the geometry, determine whether points or rectangles lie partly or entirely within the interior of theShape
, and retrieve aPathIterator
object that describes the trajectory path of theShape
outline.Definition of insideness: A point is considered to lie inside a
Shape
if and only if:- it lies completely inside the
Shape
boundary or - it lies exactly on the
Shape
boundary and the space immediately adjacent to the point in the increasingX
direction is entirely inside the boundary or - it lies exactly on a horizontal boundary segment and the space immediately adjacent to the point in the increasing
Y
direction is inside the boundary.
The
contains
andintersects
methods consider the interior of aShape
to be the area it encloses as if it were filled. This means that these methods consider unclosed shapes to be implicitly closed for the purpose of determining if a shape contains or intersects a rectangle or if a shape contains a point.- Since:
- 1.2
- See Also:
-
PathIterator
,AffineTransform
,FlatteningPathIterator
,GeneralPath
-
-
Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method and Description boolean
contains(double x, double y)
Tests if the specified coordinates are inside the boundary of theShape
, as described by the definition of insideness.boolean
contains(double x, double y, double w, double h)
Tests if the interior of theShape
entirely contains the specified rectangular area.boolean
contains(Point2D p)
Tests if a specifiedPoint2D
is inside the boundary of theShape
, as described by the definition of insideness.boolean
contains(Rectangle2D r)
Tests if the interior of theShape
entirely contains the specifiedRectangle2D
.Rectangle
getBounds()
Returns an integerRectangle
that completely encloses theShape
.Rectangle2D
getBounds2D()
Returns a high precision and more accurate bounding box of theShape
than thegetBounds
method.PathIterator
getPathIterator(AffineTransform at)
Returns an iterator object that iterates along theShape
boundary and provides access to the geometry of theShape
outline.PathIterator
getPathIterator(AffineTransform at, double flatness)
Returns an iterator object that iterates along theShape
boundary and provides access to a flattened view of theShape
outline geometry.boolean
intersects(double x, double y, double w, double h)
Tests if the interior of theShape
intersects the interior of a specified rectangular area.boolean
intersects(Rectangle2D r)
Tests if the interior of theShape
intersects the interior of a specifiedRectangle2D
.
-
-
-
Method Detail
getBounds
Rectangle getBounds()
Returns an integerRectangle
that completely encloses theShape
. Note that there is no guarantee that the returnedRectangle
is the smallest bounding box that encloses theShape
, only that theShape
lies entirely within the indicatedRectangle
. The returnedRectangle
might also fail to completely enclose theShape
if theShape
overflows the limited range of the integer data type. ThegetBounds2D
method generally returns a tighter bounding box due to its greater flexibility in representation.Note that the definition of insideness can lead to situations where points on the defining outline of the
shape
may not be considered contained in the returnedbounds
object, but only in cases where those points are also not considered contained in the originalshape
.If a
point
is inside theshape
according to thecontains(point)
method, then it must be inside the returnedRectangle
bounds object according to thecontains(point)
method of thebounds
. Specifically:shape.contains(x,y)
requiresbounds.contains(x,y)
If a
point
is not inside theshape
, then it might still be contained in thebounds
object:bounds.contains(x,y)
does not implyshape.contains(x,y)
- Returns:
-
an integer
Rectangle
that completely encloses theShape
. - Since:
- 1.2
- See Also:
-
getBounds2D()
getBounds2D
Rectangle2D getBounds2D()
Returns a high precision and more accurate bounding box of theShape
than thegetBounds
method. Note that there is no guarantee that the returnedRectangle2D
is the smallest bounding box that encloses theShape
, only that theShape
lies entirely within the indicatedRectangle2D
. The bounding box returned by this method is usually tighter than that returned by thegetBounds
method and never fails due to overflow problems since the return value can be an instance of theRectangle2D
that uses double precision values to store the dimensions.Note that the definition of insideness can lead to situations where points on the defining outline of the
shape
may not be considered contained in the returnedbounds
object, but only in cases where those points are also not considered contained in the originalshape
.If a
point
is inside theshape
according to thecontains(point)
method, then it must be inside the returnedRectangle2D
bounds object according to thecontains(point)
method of thebounds
. Specifically:shape.contains(p)
requiresbounds.contains(p)
If a
point
is not inside theshape
, then it might still be contained in thebounds
object:bounds.contains(p)
does not implyshape.contains(p)
- Returns:
-
an instance of
Rectangle2D
that is a high-precision bounding box of theShape
. - Since:
- 1.2
- See Also:
-
getBounds()
contains
boolean contains(double x, double y)
Tests if the specified coordinates are inside the boundary of theShape
, as described by the definition of insideness.- Parameters:
-
x
- the specified X coordinate to be tested -
y
- the specified Y coordinate to be tested - Returns:
-
true
if the specified coordinates are inside theShape
boundary;false
otherwise. - Since:
- 1.2
contains
boolean contains(Point2D p)
Tests if a specifiedPoint2D
is inside the boundary of theShape
, as described by the definition of insideness.- Parameters:
-
p
- the specifiedPoint2D
to be tested - Returns:
-
true
if the specifiedPoint2D
is inside the boundary of theShape
;false
otherwise. - Since:
- 1.2
intersects
boolean intersects(double x, double y, double w, double h)
Tests if the interior of theShape
intersects the interior of a specified rectangular area. The rectangular area is considered to intersect theShape
if any point is contained in both the interior of theShape
and the specified rectangular area.The
Shape.intersects()
method allows aShape
implementation to conservatively returntrue
when:- there is a high probability that the rectangular area and the
Shape
intersect, but - the calculations to accurately determine this intersection are prohibitively expensive.
Shapes
this method might returntrue
even though the rectangular area does not intersect theShape
. TheArea
class performs more accurate computations of geometric intersection than mostShape
objects and therefore can be used if a more precise answer is required.- Parameters:
-
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 - Returns:
-
true
if the interior of theShape
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. - Since:
- 1.2
- See Also:
-
Area
- there is a high probability that the rectangular area and the
intersects
boolean intersects(Rectangle2D r)
Tests if the interior of theShape
intersects the interior of a specifiedRectangle2D
. TheShape.intersects()
method allows aShape
implementation to conservatively returntrue
when:- there is a high probability that the
Rectangle2D
and theShape
intersect, but - the calculations to accurately determine this intersection are prohibitively expensive.
Shapes
this method might returntrue
even though theRectangle2D
does not intersect theShape
. TheArea
class performs more accurate computations of geometric intersection than mostShape
objects and therefore can be used if a more precise answer is required.- Parameters:
-
r
- the specifiedRectangle2D
- Returns:
-
true
if the interior of theShape
and the interior of the specifiedRectangle2D
intersect, or are both highly likely to intersect and intersection calculations would be too expensive to perform;false
otherwise. - Since:
- 1.2
- See Also:
-
intersects(double, double, double, double)
- there is a high probability that the
contains
boolean contains(double x, double y, double w, double h)
Tests if the interior of theShape
entirely contains the specified rectangular area. All coordinates that lie inside the rectangular area must lie within theShape
for the entire rectangular area to be considered contained within theShape
.The
Shape.contains()
method allows aShape
implementation to conservatively returnfalse
when:- the
intersect
method returnstrue
and - the calculations to determine whether or not the
Shape
entirely contains the rectangular area are prohibitively expensive.
Shapes
this method might returnfalse
even though theShape
contains the rectangular area. TheArea
class performs more accurate geometric computations than mostShape
objects and therefore can be used if a more precise answer is required.- Parameters:
-
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 - Returns:
-
true
if the interior of theShape
entirely contains the specified rectangular area;false
otherwise or, if theShape
contains the rectangular area and theintersects
method returnstrue
and the containment calculations would be too expensive to perform. - Since:
- 1.2
- See Also:
-
Area
,intersects(double, double, double, double)
- the
contains
boolean contains(Rectangle2D r)
Tests if the interior of theShape
entirely contains the specifiedRectangle2D
. TheShape.contains()
method allows aShape
implementation to conservatively returnfalse
when:- the
intersect
method returnstrue
and - the calculations to determine whether or not the
Shape
entirely contains theRectangle2D
are prohibitively expensive.
Shapes
this method might returnfalse
even though theShape
contains theRectangle2D
. TheArea
class performs more accurate geometric computations than mostShape
objects and therefore can be used if a more precise answer is required.- Parameters:
-
r
- The specifiedRectangle2D
- Returns:
-
true
if the interior of theShape
entirely contains theRectangle2D
;false
otherwise or, if theShape
contains theRectangle2D
and theintersects
method returnstrue
and the containment calculations would be too expensive to perform. - Since:
- 1.2
- See Also:
-
contains(double, double, double, double)
- the
getPathIterator
PathIterator getPathIterator(AffineTransform at)
Returns an iterator object that iterates along theShape
boundary and provides access to the geometry of theShape
outline. If an optionalAffineTransform
is specified, the coordinates returned in the iteration are transformed accordingly.Each call to this method returns a fresh
PathIterator
object that traverses the geometry of theShape
object independently from any otherPathIterator
objects in use at the same time.It is recommended, but not guaranteed, that objects implementing the
Shape
interface isolate iterations that are in process from any changes that might occur to the original object's geometry during such iterations.- Parameters:
-
at
- an optionalAffineTransform
to be applied to the coordinates as they are returned in the iteration, ornull
if untransformed coordinates are desired - Returns:
-
a new
PathIterator
object, which independently traverses the geometry of theShape
. - Since:
- 1.2
getPathIterator
PathIterator getPathIterator(AffineTransform at, double flatness)
Returns an iterator object that iterates along theShape
boundary and provides access to a flattened view of theShape
outline geometry.Only SEG_MOVETO, SEG_LINETO, and SEG_CLOSE point types are returned by the iterator.
If an optional
AffineTransform
is specified, the coordinates returned in the iteration are transformed accordingly.The amount of subdivision of the curved segments is controlled by the
flatness
parameter, which specifies the maximum distance that any point on the unflattened transformed curve can deviate from the returned flattened path segments. Note that a limit on the accuracy of the flattened path might be silently imposed, causing very small flattening parameters to be treated as larger values. This limit, if there is one, is defined by the particular implementation that is used.Each call to this method returns a fresh
PathIterator
object that traverses theShape
object geometry independently from any otherPathIterator
objects in use at the same time.It is recommended, but not guaranteed, that objects implementing the
Shape
interface isolate iterations that are in process from any changes that might occur to the original object's geometry during such iterations.- Parameters:
-
at
- an optionalAffineTransform
to be applied to the coordinates as they are returned in the iteration, ornull
if untransformed coordinates are desired -
flatness
- the maximum distance that the line segments used to approximate the curved segments are allowed to deviate from any point on the original curve - Returns:
-
a new
PathIterator
that independently traverses a flattened view of the geometry of theShape
. - Since:
- 1.2
-
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