com.spatial4j.core.shape.impl

Class PointImpl

java.lang.Object

com.spatial4j.core.shape.impl.PointImpl

All Implemented Interfaces:

Point, Shape

public class PointImpl
extends Object
implements Point

A basic 2D implementation of a Point.

Constructor Summary

Constructors

Constructor and Description
PointImpl(double x, double y, SpatialContext ctx) A simple constructor without normalization / validation.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object o) The sub-classes of Shape generally implement the same contract for Object.equals(Object) and Object.hashCode() amongst the same sub-interface type.
static boolean	equals(Point thiz, Object o) All Point implementations should use this definition of Object.equals(Object).
double	getArea(SpatialContext ctx) Calculates the area of the shape, in square-degrees.
Rectangle	getBoundingBox() Get the bounding box for this Shape.
Circle	getBuffered(double distance, SpatialContext ctx) Returns a buffered version of this shape.
PointImpl	getCenter() Returns the center point of this shape.
double	getX() The X coordinate, or Longitude in geospatial contexts.
double	getY() The Y coordinate, or Latitude in geospatial contexts.
boolean	hasArea() Does the shape have area? This will be false for points and lines.
int	hashCode()
static int	hashCode(Point thiz) All Point implementations should use this definition of Object.hashCode().
boolean	isEmpty() Shapes can be "empty", which is to say it exists nowhere.
SpatialRelation	relate(Shape other) Describe the relationship between the two objects.
void	reset(double x, double y) Expert: Resets the state of this shape given the arguments.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

PointImpl

public PointImpl(double x,
         double y,
         SpatialContext ctx)

A simple constructor without normalization / validation.

Method Detail

isEmpty

public boolean isEmpty()

Description copied from interface: Shape

Shapes can be "empty", which is to say it exists nowhere. The underlying coordinates are typically NaN.

Specified by:

isEmpty in interface Shape

reset

public void reset(double x,
         double y)

Description copied from interface: Point

Expert: Resets the state of this shape given the arguments. This is a performance feature to avoid excessive Shape object allocation as well as some argument error checking. Mutable shapes is error-prone so use with care.

Specified by:

reset in interface Point

getX

public double getX()

Description copied from interface: Point

The X coordinate, or Longitude in geospatial contexts.

Specified by:

getX in interface Point

getY

public double getY()

Description copied from interface: Point

The Y coordinate, or Latitude in geospatial contexts.

Specified by:

getY in interface Point

getBoundingBox

public Rectangle getBoundingBox()

Description copied from interface: Shape

Get the bounding box for this Shape. This means the shape is within the bounding box and that it touches each side of the rectangle.

Postcondition: this.getBoundingBox().relate(this) == CONTAINS

Specified by:

getBoundingBox in interface Shape

getCenter

public PointImpl getCenter()

Description copied from interface: Shape

Returns the center point of this shape. This is usually the same as getBoundingBox().getCenter() but it doesn't have to be.

Postcondition: this.relate(this.getCenter()) == CONTAINS

Specified by:

getCenter in interface Shape

getBuffered

public Circle getBuffered(double distance,
                 SpatialContext ctx)

Description copied from interface: Shape

Returns a buffered version of this shape. The buffer is usually a rounded-corner buffer, although some shapes might buffer differently. This is an optional operation.

Specified by:

getBuffered in interface Shape

Returns:

Not null, and the returned shape should contain the current shape.

relate

public SpatialRelation relate(Shape other)

Description copied from interface: Shape

Describe the relationship between the two objects. For example

• this is WITHIN other
• this CONTAINS other
• this is DISJOINT other
• this INTERSECTS other

Note that a Shape implementation may choose to return INTERSECTS when the true answer is WITHIN or CONTAINS for performance reasons. If a shape does this then it must document when it does. Ideally the shape will not do this approximation in all circumstances, just sometimes.

If the shapes are equal then the result is CONTAINS (preferred) or WITHIN.

Specified by:

relate in interface Shape

hasArea

public boolean hasArea()

Description copied from interface: Shape

Does the shape have area? This will be false for points and lines. It will also be false for shapes that normally have area but are constructed in a degenerate case as to not have area (e.g. a circle with 0 radius or rectangle with no height or no width).

Specified by:

hasArea in interface Shape

getArea

public double getArea(SpatialContext ctx)

Description copied from interface: Shape

Calculates the area of the shape, in square-degrees. If ctx is null then simple Euclidean calculations will be used. This figure can be an estimate.

Specified by:

getArea in interface Shape

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Description copied from interface: Shape

The sub-classes of Shape generally implement the same contract for Object.equals(Object) and Object.hashCode() amongst the same sub-interface type. This means, for example, that multiple Point implementations of different classes are equal if they share the same x & y.

Specified by:

equals in interface Shape

Overrides:

equals in class Object

equals

public static boolean equals(Point thiz,
             Object o)

All Point implementations should use this definition of Object.equals(Object).

hashCode

public int hashCode()

Overrides:

hashCode in class Object

hashCode

public static int hashCode(Point thiz)

All Point implementations should use this definition of Object.hashCode().