Class Cell

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

Note

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

Inheritance

object

Cell

Implements

IComparable<Cell>

Inherited Members

object.Equals(object, object)

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: Lucene.Net.Spatial.Prefix.Tree

Assembly: Lucene.Net.Spatial.dll

Syntax

public abstract class Cell : IComparable<Cell>

Constructors

Cell(SpatialPrefixTree, byte[], int, int)

Initializes a new instance of Cell for the spatialPrefixTree with the specified bytes, offset and length.

Declaration

protected Cell(SpatialPrefixTree spatialPrefixTree, byte[] bytes, int offset, int length)

Parameters

Type	Name	Description
SpatialPrefixTree	spatialPrefixTree	The SpatialPrefixTree this instance belongs to.
byte[]	bytes	The representation of this Cell.
int	offset	The offset into bytes to use.
int	length	The count of bytes to use.

Exceptions

Type	Condition
ArgumentNullException	spatialPrefixTree or bytes is null.

Cell(SpatialPrefixTree, string)

Initializes a new instance of Cell for the spatialPrefixTree with the specified token.

Declaration

protected Cell(SpatialPrefixTree spatialPrefixTree, string token)

Parameters

Type	Name	Description
SpatialPrefixTree	spatialPrefixTree	The SpatialPrefixTree this instance belongs to.
string	token	The string representation of this Cell.

Exceptions

Type	Condition
ArgumentNullException	spatialPrefixTree or token is null.

Fields

LEAF_BYTE

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

Note

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

Declaration

public const byte LEAF_BYTE = 43

Field Value

Type	Description
byte

m_leaf

Always false for points.

Declaration

protected bool m_leaf

Field Value

Type	Description
bool

Remarks

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.

m_shapeRel

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

Declaration

protected SpatialRelation m_shapeRel

Field Value

Type	Description
SpatialRelation

m_spatialPrefixTree

LUCENENET specific - we need to set the SpatialPrefixTree before calling overridden members of this class, just in case those overridden members require it. This is not possible from the subclass because the constructor of the base class runs first. So we need to move the reference here and also set it before running the normal constructor logic.

Declaration

protected readonly SpatialPrefixTree m_spatialPrefixTree

Field Value

Type	Description
SpatialPrefixTree

Properties

Center

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

Note

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

Declaration

public virtual IPoint Center { get; }

Property Value

Type	Description
IPoint

IsLeaf

For points, this is always false.

Declaration

public virtual bool IsLeaf { get; }

Property Value

Type	Description
bool

Remarks

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).

Level

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

Note

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

Declaration

public virtual int Level { get; }

Property Value

Type	Description
int

Shape

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

Note

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

Declaration

public abstract IShape Shape { get; }

Property Value

Type	Description
IShape

ShapeRel

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

Note

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

Declaration

public virtual SpatialRelation ShapeRel { get; }

Property Value

Type	Description
SpatialRelation

SubCellsSize

GetSubCells().Count -- usually a constant. Should be >=2

Declaration

public abstract int SubCellsSize { get; }

Property Value

Type	Description
int

TokenString

Note: doesn't contain a trailing leaf byte.

Declaration

public virtual string TokenString { get; }

Property Value

Type	Description
string

Methods

CompareTo(Cell?)

Compares the current instance with another object of the same type and returns an integer that indicates whether the current instance precedes, follows, or occurs in the same position in the sort order as the other object.

Declaration

public virtual int CompareTo(Cell? other)

Parameters

Type	Name	Description
Cell	other	An object to compare with this instance.

Returns

Type	Description
int	A value that indicates the relative order of the objects being compared. The return value has these meanings: Value Meaning Less than zero This instance precedes other in the sort order. Zero This instance occurs in the same position in the sort order as other. Greater than zero This instance follows other in the sort order.

Equals(object?)

Determines whether the specified object is equal to the current object.

Declaration

public override bool Equals(object? obj)

Parameters

Type	Name	Description
object	obj	The object to compare with the current object.

Returns

Type	Description
bool	true if the specified object is equal to the current object; otherwise, false.

Overrides

object.Equals(object)

GetHashCode()

Serves as the default hash function.

Declaration

public override int GetHashCode()

Returns

Type	Description
int	A hash code for the current object.

Overrides

object.GetHashCode()

GetSubCell(IPoint)

Performant implementations are expected to implement this efficiently by considering the current cell's boundary.

Declaration

public abstract Cell GetSubCell(IPoint p)

Parameters

Type	Name	Description
IPoint	p

Returns

Type	Description
Cell

Remarks

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

Precondition: this.Shape.Relate(p) != SpatialRelation.DISJOINT.

GetSubCells()

Gets the cells at the next grid cell level that cover this cell.

Declaration

protected abstract ICollection<Cell> GetSubCells()

Returns

Type	Description
ICollection<Cell>	A set of cells (no dups), sorted, modifiable, not empty, not null.

Remarks

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

GetSubCells(IShape?)

Like GetSubCells() but with the results filtered by a shape. If that shape is a Spatial4n.Shapes.IPoint then it must call GetSubCell(IPoint). The returned cells should have ShapeRel set to their relation with shapeFilter. In addition, IsLeaf must be true when that relation is Spatial4n.Shapes.SpatialRelation.WITHIN.

Precondition: Never called when Level == maxLevel.

Declaration

public virtual ICollection<Cell> GetSubCells(IShape? shapeFilter)

Parameters

Type	Name	Description
IShape	shapeFilter	an optional filter for the returned cells.

Returns

Type	Description
ICollection<Cell>	A set of cells (no dups), sorted. Not Modifiable.

GetTokenBytes()

Note: doesn't contain a trailing leaf byte.

Declaration

public virtual byte[] GetTokenBytes()

Returns

Type	Description
byte[]

Reset(byte[], int, int)

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

Note

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

Declaration

public virtual void Reset(byte[] bytes, int offset, int length)

Parameters

Type	Name	Description
byte[]	bytes
int	offset
int	length

SetLeaf()

Note: not supported at level 0.

NOTE: When overriding this method, be aware that the constructor of this class calls 
a private method and not this virtual method. So if you need to override
the behavior during the initialization, call your own private method from the constructor
with whatever custom behavior you need.

Declaration

public virtual void SetLeaf()

ToString()

Returns a string that represents the current object.

Declaration

public override string ToString()

Returns

Type	Description
string	A string that represents the current object.

Overrides

object.ToString()

Implements

IComparable<T>