org.apache.lucene.spatial.prefix.tree
Class Cell

java.lang.Object
  org.apache.lucene.spatial.prefix.tree.Cell

All Implemented Interfaces:

Comparable<Cell>

public abstract class Cell
extends Object
implements Comparable<Cell>

Represents a grid cell. These are not necessarily thread-safe, although new Cell("") (world cell) must be.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

protected boolean	leaf Always false for points.
static byte	LEAF_BYTE
protected com.spatial4j.core.shape.SpatialRelation	shapeRel When set via getSubCells(filter), it is the relationship between this cell and the given shape filter.

Constructor Summary

protected	Cell(byte[] bytes, int off, int len)
protected	Cell(String token)

Method Summary

int	compareTo(Cell o)
boolean	equals(Object obj)
com.spatial4j.core.shape.Point	getCenter()
int	getLevel()
abstract com.spatial4j.core.shape.Shape	getShape()
com.spatial4j.core.shape.SpatialRelation	getShapeRel()
abstract Cell	getSubCell(com.spatial4j.core.shape.Point p) Performant implementations are expected to implement this efficiently by considering the current cell's boundary.
protected abstract Collection<Cell>	getSubCells() Gets the cells at the next grid cell level that cover this cell.
Collection<Cell>	getSubCells(com.spatial4j.core.shape.Shape shapeFilter) Like getSubCells() but with the results filtered by a shape.
abstract int	getSubCellsSize() getSubCells().size() -- usually a constant.
byte[]	getTokenBytes() Note: doesn't contain a trailing leaf byte.
String	getTokenString() Note: doesn't contain a trailing leaf byte.
int	hashCode()
boolean	isLeaf() For points, this is always false.
void	reset(byte[] bytes, int off, int len)
void	setLeaf() Note: not supported at level 0.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

LEAF_BYTE

public static final byte LEAF_BYTE

See Also:

Constant Field Values

shapeRel

protected com.spatial4j.core.shape.SpatialRelation shapeRel

When set via getSubCells(filter), it is the relationship between this cell and the given shape filter.

leaf

protected boolean leaf

Always false for points. Otherwise, indicate no further sub-cells are going to be provided because shapeRel is WITHIN or maxLevels or a detailLevel is hit.

Constructor Detail

Cell

protected Cell(String token)

Cell

protected Cell(byte[] bytes,
               int off,
               int len)

Method Detail

reset

public void reset(byte[] bytes,
                  int off,
                  int len)

getShapeRel

public com.spatial4j.core.shape.SpatialRelation getShapeRel()

isLeaf

public boolean isLeaf()

For points, this is always false. Otherwise this is true if there are no further cells with this prefix for the shape (always true at maxLevels).

setLeaf

public void setLeaf()

Note: not supported at level 0.

getTokenString

public String getTokenString()

Note: doesn't contain a trailing leaf byte.

getTokenBytes

public byte[] getTokenBytes()

Note: doesn't contain a trailing leaf byte.

getLevel

public int getLevel()

getSubCells

public Collection<Cell> getSubCells(com.spatial4j.core.shape.Shape shapeFilter)

Like getSubCells() but with the results filtered by a shape. If that shape is a Point then it must call getSubCell(com.spatial4j.core.shape.Point). The returned cells should have getShapeRel() set to their relation with shapeFilter. In addition, isLeaf() must be true when that relation is WITHIN.

Precondition: Never called when getLevel() == maxLevel.

Parameters:

shapeFilter - an optional filter for the returned cells.

Returns:

A set of cells (no dups), sorted. Not Modifiable.

getSubCell

public abstract Cell getSubCell(com.spatial4j.core.shape.Point p)

Performant implementations are expected to implement this efficiently by considering the current cell's boundary. Precondition: Never called when getLevel() == maxLevel.

Precondition: this.getShape().relate(p) != DISJOINT.

getSubCells

protected abstract Collection<Cell> getSubCells()

Gets the cells at the next grid cell level that cover this cell. Precondition: Never called when getLevel() == maxLevel.

Returns:

A set of cells (no dups), sorted, modifiable, not empty, not null.

getSubCellsSize

public abstract int getSubCellsSize()

getSubCells().size() -- usually a constant. Should be >=2

getShape

public abstract com.spatial4j.core.shape.Shape getShape()

getCenter

public com.spatial4j.core.shape.Point getCenter()

compareTo

public int compareTo(Cell o)

Specified by:

compareTo in interface Comparable<Cell>

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object