public interface Shape
Shape interface provides definitions for objects that represent some form of geometric shape. The
Shape is described by a
PathIterator object, which can express the outline of the
Shape as well as a rule for determining how the outline divides the 2D plane into interior and exterior points. Each
Shape object provides callbacks to get the bounding box of the geometry, determine whether points or rectangles lie partly or entirely within the interior of the
Shape, and retrieve a
PathIterator object that describes the trajectory path of the
Shape outline.
Definition of insideness: A point is considered to lie inside a Shape if and only if:
Shape boundary or Shape boundary and the space immediately adjacent to the point in the increasing X direction is entirely inside the boundary or Y direction is inside the boundary. The contains and intersects methods consider the interior of a Shape 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.
PathIterator,
AffineTransform,
FlatteningPathIterator,
GeneralPath
| Modifier and Type | Method and Description |
|---|---|
boolean |
contains(double x, double y)
Tests if the specified coordinates are inside the boundary of the
Shape, as described by the
definition of insideness.
|
boolean |
contains(double x, double y, double w, double h)
Tests if the interior of the
Shape entirely contains the specified rectangular area.
|
boolean |
contains(Point2D
Tests if a specified
Point2D is inside the boundary of the
Shape, as described by the
definition of insideness.
|
boolean |
contains(Rectangle2D
Tests if the interior of the
Shape entirely contains the specified
Rectangle2D.
|
Rectangle |
getBounds()
Returns an integer
Rectangle that completely encloses the
Shape.
|
Rectangle2D |
getBounds2D()
Returns a high precision and more accurate bounding box of the
Shape than the
getBounds method.
|
PathIterator |
getPathIterator(AffineTransform
Returns an iterator object that iterates along the
Shape boundary and provides access to the geometry of the
Shape outline.
|
PathIterator |
getPathIterator(AffineTransform
Returns an iterator object that iterates along the
Shape boundary and provides access to a flattened view of the
Shape outline geometry.
|
boolean |
intersects(double x, double y, double w, double h)
Tests if the interior of the
Shape intersects the interior of a specified rectangular area.
|
boolean |
intersects(Rectangle2D
Tests if the interior of the
Shape intersects the interior of a specified
Rectangle2D.
|
RectanglegetBounds()
Rectangle that completely encloses the
Shape. Note that there is no guarantee that the returned
Rectangle is the smallest bounding box that encloses the
Shape, only that the
Shape lies entirely within the indicated
Rectangle. The returned
Rectangle might also fail to completely enclose the
Shape if the
Shape overflows the limited range of the integer data type. The
getBounds2D 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 returned bounds object, but only in cases where those points are also not considered contained in the original shape.
If a point is inside the shape according to the contains(point) method, then it must be inside the returned Rectangle bounds object according to the contains(point) method of the bounds. Specifically:
shape.contains(x,y) requires bounds.contains(x,y)
If a point is not inside the shape, then it might still be contained in the bounds object:
bounds.contains(x,y) does not imply shape.contains(x,y)
Rectangle that completely encloses the
Shape.
getBounds2D()
Rectangle2DgetBounds2D()
Shape than the
getBounds method. Note that there is no guarantee that the returned
Rectangle2D is the smallest bounding box that encloses the
Shape, only that the
Shape lies entirely within the indicated
Rectangle2D. The bounding box returned by this method is usually tighter than that returned by the
getBounds method and never fails due to overflow problems since the return value can be an instance of the
Rectangle2D 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 returned bounds object, but only in cases where those points are also not considered contained in the original shape.
If a point is inside the shape according to the contains(point) method, then it must be inside the returned Rectangle2D bounds object according to the contains(point) method of the bounds. Specifically:
shape.contains(p) requires bounds.contains(p)
If a point is not inside the shape, then it might still be contained in the bounds object:
bounds.contains(p) does not imply shape.contains(p)
Rectangle2D that is a high-precision bounding box of the
Shape.
getBounds()
boolean contains(double x,
double y)
Shape, as described by the
definition of insideness.
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.
boolean contains(Point2Dp)
Point2D is inside the boundary of the
Shape, as described by the
definition of insideness.
p - the specified
Point2D to be tested
true if the specified
Point2D is inside the boundary of the
Shape;
false otherwise.
boolean intersects(double x,
double y,
double w,
double h)
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.
Area
boolean intersects(Rectangle2Dr)
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.
intersects(double, double, double, double)
boolean contains(double x,
double y,
double w,
double h)
Shape entirely contains the specified rectangular area. All coordinates that lie inside the rectangular area must lie within the
Shape for the entire rectangular 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.
Area,
intersects(double, double, double, double)
boolean contains(Rectangle2Dr)
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.
contains(double, double, double, double)
PathIteratorgetPathIterator(AffineTransform at)
Shape boundary and provides access to the geometry of the
Shape outline. If an optional
AffineTransform 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 the Shape object independently from any other PathIterator 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.
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, which independently traverses the geometry of the
Shape.
PathIteratorgetPathIterator(AffineTransform at, double flatness)
Shape boundary and provides access to a flattened view of the
Shape 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 the Shape object geometry independently from any other PathIterator 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.
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 distance that the line segments used to approximate the curved segments are allowed to deviate from any point on the original curve
PathIterator that independently traverses a flattened view of the geometry of the
Shape.