Module java.desktop

Package java.awt.geom

Class Ellipse2D

java.lang.Object

java.awt.geom.RectangularShape

java.awt.geom.Ellipse2D

All Implemented Interfaces:

Shape, Cloneable

Direct Known Subclasses:

Ellipse2D.Double, Ellipse2D.Float

public abstract class Ellipse2D
extends RectangularShape

The Ellipse2D class describes an ellipse that is defined by a framing rectangle.

This class is only the abstract superclass for all objects which store a 2D ellipse. The actual storage representation of the coordinates is left to the subclass.

Since:

1.2

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Ellipse2D.Double	The Double class defines an ellipse specified in double precision.
static class	Ellipse2D.Float	The Float class defines an ellipse specified in float precision.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Ellipse2D()	This is an abstract class that cannot be instantiated directly.

Method Summary

Modifier and Type	Method	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	equals(Object obj)	Determines whether or not the specified Object is equal to this Ellipse2D.
PathIterator	getPathIterator(AffineTransform at)	Returns an iteration object that defines the boundary of this Ellipse2D.
int	hashCode()	Returns the hashcode for this Ellipse2D.
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.

Methods inherited from class java.lang.Object

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

Methods inherited from class java.awt.geom.RectangularShape

clone, contains, contains, getBounds, getCenterX, getCenterY, getFrame, getHeight, getMaxX, getMaxY, getMinX, getMinY, getPathIterator, getWidth, getX, getY, intersects, isEmpty, setFrame, setFrame, setFrame, setFrameFromCenter, setFrameFromCenter, setFrameFromDiagonal, setFrameFromDiagonal

Methods inherited from interface java.awt.Shape

getBounds2D

Constructor Detail

Ellipse2D

protected Ellipse2D()

This is an abstract class that cannot be instantiated directly. Type-specific implementation subclasses are available for instantiation and provide a number of formats for storing the information necessary to satisfy the various accessor methods below.

Since:

1.2

See Also:

Ellipse2D.Float, Ellipse2D.Double

Method Detail

contains

public 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.

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 the Shape boundary; false otherwise.

Since:

1.2

intersects

public 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. 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:

• there is a high probability that the rectangular area and the Shape intersect, but
• the calculations to accurately determine this intersection are prohibitively expensive.

This means that for some 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.

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 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.

Since:

1.2

See Also:

Area

contains

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

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 rectangular area to be considered contained within the Shape.

The Shape.contains() method allows a Shape implementation to conservatively return false when:

• the intersect method returns true and
• the calculations to determine whether or not the Shape entirely contains the rectangular area are prohibitively expensive.

This means that for some 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.

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 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.

Since:

1.2

See Also:

Area, Shape.intersects(double, double, double, double)

getPathIterator

public PathIterator getPathIterator(AffineTransform at)

Returns an iteration object that defines the boundary of this Ellipse2D. The iterator for this class is multi-threaded safe, which means that this Ellipse2D class guarantees that modifications to the geometry of this Ellipse2D object do not affect any iterations of that geometry that are already in process.

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 Ellipse2D, one segment at a time.

Since:

1.2

hashCode

public int hashCode()

Returns the hashcode for this Ellipse2D.

Overrides:

hashCode in class Object

Returns:

the hashcode for this Ellipse2D.

Since:

1.6

See Also:

Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

equals

public boolean equals(Object obj)

Determines whether or not the specified Object is equal to this Ellipse2D. The specified Object is equal to this Ellipse2D if it is an instance of Ellipse2D and if its location and size are the same as this Ellipse2D.

Overrides:

equals in class Object

Parameters:

obj - an Object to be compared with this Ellipse2D.

Returns:

true if obj is an instance of Ellipse2D and has the same values; false otherwise.

Since:

1.6

See Also:

Object.hashCode(), HashMap