org.kynosarges.tektosyne.subdivision

Class SubdivisionElement

java.lang.Object

org.kynosarges.tektosyne.subdivision.SubdivisionElement

public final class SubdivisionElement
extends java.lang.Object

Represents one element of a planar Subdivision. Immutable class containing either an Subdivision.edges(), Subdivision.faces(), Subdivision.vertices() element of a planar Subdivision. A SubdivisionElementType value indicates which element type is present.

Field Summary

Fields

Modifier and Type	Field and Description
java.lang.Object	content The actual Subdivision element stored in the SubdivisionElement.
static SubdivisionElement	NULL_FACE A SubdivisionElement of type SubdivisionElementType.FACE whose face() is null.
SubdivisionElementType	type The SubdivisionElementType of the SubdivisionElement.

Constructor Summary

Constructors

Constructor and Description
SubdivisionElement(PointD vertex) Creates a SubdivisionElement of type SubdivisionElementType.VERTEX with the specified PointD vertex.
SubdivisionElement(SubdivisionEdge edge) Creates a SubdivisionElement of type SubdivisionElementType.EDGE with the specified SubdivisionEdge.
SubdivisionElement(SubdivisionFace face) Creates a SubdivisionElement of type SubdivisionElementType.FACE with the specified SubdivisionFace.

Method Summary

Modifier and Type	Method and Description
SubdivisionEdge	edge() Gets the SubdivisionEdge stored in the SubdivisionElement.
boolean	equals(java.lang.Object obj) Compares the specified Object to this SubdivisionElement instance.
SubdivisionFace	face() Gets the SubdivisionFace stored in the SubdivisionElement.
int	hashCode() Returns a hash code for the SubdivisionElement.
boolean	isUnboundedFace() Indicates whether the SubdivisionElement represents an unbounded SubdivisionFace.
java.lang.String	toString() Returns a String representation of the SubdivisionElement.
PointD	vertex() Gets the PointD vertex stored in the SubdivisionElement.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

NULL_FACE

public static final SubdivisionElement NULL_FACE

A SubdivisionElement of type SubdivisionElementType.FACE whose face() is null. By convention, NULL_FACE represents the unbounded face of a planar Subdivision. Use isUnboundedFace() to test for this condition, as well as for the actual unbounded SubdivisionFace.

content

public final java.lang.Object content

The actual Subdivision element stored in the SubdivisionElement. Contains either a SubdivisionEdge, a SubdivisionFace, or a PointD vertex. Use edge(), face() and vertex() for type-safe access.

type

public final SubdivisionElementType type

The SubdivisionElementType of the SubdivisionElement. Never null.

Constructor Detail

SubdivisionElement

public SubdivisionElement(SubdivisionEdge edge)

Creates a SubdivisionElement of type SubdivisionElementType.EDGE with the specified SubdivisionEdge.

Parameters:

edge - the SubdivisionEdge to store

Throws:

java.lang.NullPointerException - if edge is null

SubdivisionElement

public SubdivisionElement(SubdivisionFace face)

Creates a SubdivisionElement of type SubdivisionElementType.FACE with the specified SubdivisionFace. face may be null to represent an unbounded face, see NULL_FACE and isUnboundedFace().

Parameters:

face - the SubdivisionFace to store

SubdivisionElement

public SubdivisionElement(PointD vertex)

Creates a SubdivisionElement of type SubdivisionElementType.VERTEX with the specified PointD vertex.

Parameters:

vertex - the PointD vertex to store

Throws:

java.lang.NullPointerException - if vertex is null

Method Detail

edge

public SubdivisionEdge edge()

Gets the SubdivisionEdge stored in the SubdivisionElement. Never returns null.

Returns:

the SubdivisionEdge stored in the SubdivisionElement

Throws:

java.lang.IllegalStateException - if type does not equal SubdivisionElementType.EDGE

face

public SubdivisionFace face()

Gets the SubdivisionFace stored in the SubdivisionElement. May return null to represent an unbounded face, see NULL_FACE and isUnboundedFace().

Returns:

the SubdivisionFace stored in the SubdivisionElement

Throws:

java.lang.IllegalStateException - if type does not equal SubdivisionElementType.FACE

isUnboundedFace

public boolean isUnboundedFace()

Indicates whether the SubdivisionElement represents an unbounded SubdivisionFace. The unbounded face of a planar Subdivision may be represented by NULL_FACE or by a valid SubdivisionFace whose SubdivisionFace.key() is zero. isUnboundedFace() tests for both conditions.

Returns:

true if type is SubdivisionElementType.FACE and face() is null or its SubdivisionFace.key() is zero, else false

vertex

public PointD vertex()

Gets the PointD vertex stored in the SubdivisionElement. Never returns null.

Returns:

the PointD vertex stored in the SubdivisionElement

Throws:

java.lang.IllegalStateException - if type does not equal SubdivisionElementType.VERTEX

equals

public boolean equals(java.lang.Object obj)

Compares the specified Object to this SubdivisionElement instance.

Overrides:

equals in class java.lang.Object

Parameters:

obj - the Object to compare to this instance

Returns:

true if obj is not null and a SubdivisionElement instance whose type and content equal those of this instance, else false

hashCode

public int hashCode()

Returns a hash code for the SubdivisionElement.

Overrides:

hashCode in class java.lang.Object

Returns:

an Integer hash code for the SubdivisionElement

toString

public java.lang.String toString()

Returns a String representation of the SubdivisionElement.

Overrides:

toString in class java.lang.Object

Returns:

a String containing the values of type and content