java.lang.Object
- com.google.common.geometry.S2Iterator<T>

```
@GwtCompatible
public final class S2Iterator<T extends S2Iterator.Entry>
extends Object
```
A random access iterator that provides low-level access to entries sorted by cell ID. The behavior of this iterator is more like a database cursor, where accessing properties at the current position does not alter the position of the cursor. The cursor has a compareTo(com.google.common.geometry.S2CellId) method to compare the value at the current position of the iterator with a given S2CellId.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static interface S2Iterator.Entry
An interface to provide the cell ID for an element in a sorted list.

Field Summary

Fields
Modifier and Type Field Description

protected int pos

Constructor Summary

Constructors
Modifier	Constructor	Description
`protected`	`S2Iterator(List<T> entries)`	Create a new iterator based on the given list of entries.
`protected`	`S2Iterator(List<T> entries, com.google.common.base.Function<S2CellId,Integer> seekFunction)`	Same as `S2Iterator(List)`, but accepts `seekFunction`, which is used as the implementation of `seek(S2CellId)`.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`atBegin()`	Returns true if the iterator is positioned at the first index cell.
`S2Point`	`center()`	Returns the center of the cell (used as a reference point for shape interiors.)
`int`	`compareTo(S2CellId cellId)`	Returns the comparison from the current iterator cell to the given cell ID.
`S2Iterator<T>`	`copy()`	Returns a copy of this iterator, positioned as this iterator is.
`boolean`	`done()`	Returns true if the iterator is positioned past the last index cell.
`T`	`entry()`	Returns the current entry.
`<T extends S2Iterator.Entry> boolean`	`equalIterators(S2Iterator<T> it)`	Returns true if these iterators have the same entries and position.
`boolean`	`equals(Object o)`	Returns true if `o` is an `S2Iterator` with equal entries and position.
`void`	`finish()`	Positions the iterator so that `done()` is true.
`int`	`hashCode()`
`S2CellId`	`id()`	Returns the cell id for the current cell.
`S2ShapeIndex.CellRelation`	`locate(S2CellId target)`	Positions the iterator at the index cell containing the given cell, if possible, and returns the `S2ShapeIndex.CellRelation` that describes the relationship between the index and the given target cell: Returns `S2ShapeIndex.CellRelation.INDEXED` if the iterator was positioned at an index cell that is equal to or contains the given cell.
`boolean`	`locate(S2Point targetPoint)`	Positions the iterator at the index cell containing "target" and returns true, or if no such cell exists in the index, the iterator is positioned arbitrarily and this method returns false.
`void`	`next()`	Advances the iterator to the next cell in the index.
`void`	`position(S2Iterator<T> it)`	Set this iterator to the position given by the other iterator.
`void`	`prev()`	Positions the iterator at the previous cell in the index.
`void`	`restart()`	Positions the iterator so that `atBegin()` is true.
`void`	`seek(S2CellId target)`	Positions the iterator at the first cell with id() >= target, or at the end of the index if no such cell exists.
`void`	`seekForward(S2CellId target)`	Advances the iterator to the next cell with id() >= target.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - pos
```
protected int pos
```
- Constructor Detail
  - S2Iterator
```
protected S2Iterator(List<T> entries)
```
    Create a new iterator based on the given list of entries. Results are undefined if the entries are not in ascending sorted order.
    
    Parameters:
    
    entries - the list of entries which back this iterator.
  - S2Iterator
```
protected S2Iterator(List<T> entries,
                     com.google.common.base.Function<S2CellId,Integer> seekFunction)
```
    Same as S2Iterator(List), but accepts seekFunction, which is used as the implementation of seek(S2CellId).
    
    Parameters:
    
    entries - the list of entries which back this iterator.
    
    seekFunction - a function which takes a target S2CellId and returns an index to which this iterator will be repositioned.
- Method Detail
  - copy
```
public S2Iterator<T> copy()
```
    Returns a copy of this iterator, positioned as this iterator is.
  - restart
```
public void restart()
```
    Positions the iterator so that atBegin() is true.
  - compareTo
```
public int compareTo(S2CellId cellId)
```
    Returns the comparison from the current iterator cell to the given cell ID.
  - equals
```
public boolean equals(Object o)
```
    Returns true if o is an S2Iterator with equal entries and position.
    
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equalIterators
```
public <T extends S2Iterator.Entry> boolean equalIterators(S2Iterator<T> it)
```
    Returns true if these iterators have the same entries and position.
  - id
```
public S2CellId id()
```
    Returns the cell id for the current cell.
  - entry
```
public T entry()
```
    Returns the current entry.
  - center
```
public S2Point center()
```
    Returns the center of the cell (used as a reference point for shape interiors.)
  - next
```
public void next()
```
    Advances the iterator to the next cell in the index. Does not advance the iterator if pos is equal to the number of cells in the index.
  - prev
```
public void prev()
```
    Positions the iterator at the previous cell in the index. Does not move the iterator if pos is equal to 0.
  - done
```
public boolean done()
```
    Returns true if the iterator is positioned past the last index cell.
  - atBegin
```
public boolean atBegin()
```
    Returns true if the iterator is positioned at the first index cell.
  - seek
```
public void seek(S2CellId target)
```
    Positions the iterator at the first cell with id() >= target, or at the end of the index if no such cell exists.
  - seekForward
```
public void seekForward(S2CellId target)
```
    Advances the iterator to the next cell with id() >= target. If the iterator is done() or already satisfies id() >= target, there is no effect.
  - finish
```
public void finish()
```
    Positions the iterator so that done() is true.
  - locate
```
public boolean locate(S2Point targetPoint)
```
    Positions the iterator at the index cell containing "target" and returns true, or if no such cell exists in the index, the iterator is positioned arbitrarily and this method returns false.
    The resulting index position is guaranteed to contain all edges that might intersect the line segment between targetPoint and center().
  - locate
```
public S2ShapeIndex.CellRelation locate(S2CellId target)
```
    Positions the iterator at the index cell containing the given cell, if possible, and returns the S2ShapeIndex.CellRelation that describes the relationship between the index and the given target cell:
    
    Returns S2ShapeIndex.CellRelation.INDEXED if the iterator was positioned at an index cell that is equal to or contains the given cell. I.e. the given target exists in the index as a leaf cell.
    Returns S2ShapeIndex.CellRelation.SUBDIVIDED if the iterator was positioned at the first of one or more cells contained by the given target cell. I.e. the target does not exist in the index, but the first of its descendants was selected.
    Returns S2ShapeIndex.CellRelation.DISJOINT if the iterator had to be positioned arbitrarily because the given target cell does not intersect any of the index's cells.
  - position
```
public void position(S2Iterator<T> it)
```
    Set this iterator to the position given by the other iterator.

Class S2Iterator<T extends S2Iterator.Entry>

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

pos

Constructor Detail

S2Iterator

S2Iterator

Method Detail

copy

restart

compareTo

equals

hashCode

equalIterators

id

entry

center

next

prev

done

atBegin

seek

seekForward

finish

locate

locate

position