Package com.google.common.geometry
Class S2CellIndex.ContentsIterator
- java.lang.Object
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- com.google.common.geometry.S2CellIndex.ContentsIterator
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- Enclosing class:
- S2CellIndex
public class S2CellIndex.ContentsIterator extends java.lang.Object
An iterator that visits the (cellId, label) pairs that cover a set of leaf cell ranges (see RangeIterator). To use it, construct an instance orclear()
an existing instance, andstartUnion(com.google.common.geometry.S2CellIndex.RangeIterator)
to visit the contents of each desired leaf cell range.Note that when multiple leaf cell ranges are visited, this class only guarantees that each result will be reported at least once, i.e. duplicate values may be suppressed. If you want duplicate values to be reported again, be sure to call
clear()
first.In particular, the implementation guarantees that when multiple leaf cell ranges are visited in monotonically increasing order, then each (cellId, label) pair is reported exactly once.
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Field Summary
Fields Modifier and Type Field Description private static int
DONE
A special label indicating thatdone()
is true.private int
nextNodeCutoff
The maximum index withinS2CellIndex.cellNodes
visited during the current call to startUnion().private S2CellIndex.CellNode
node
A copy of the current node in the cell tree.private int
nodeCutoff
The maximum index withinS2CellIndex.cellNodes
visited during the previous call to startUnion().private S2CellId
prevStartId
The value of it.startId() from the previous call to startUnion().
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Constructor Summary
Constructors Modifier Constructor Description private
ContentsIterator()
Creates a new iterator.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description S2CellId
cellId()
Returns the S2CellId of the current (cellId, label) pair.void
clear()
Clears all state with respect to which range(s) have been visited.boolean
done()
Returns true if all (cellId, label) pairs have been visited.int
label()
Returns the label of the current (cellId, label) pair.void
next()
Advances the iterator to the next (cellId, label) pair covered by the current leaf cell range.private void
setDone()
Sets the current node label to DONE to indicate that iteration has finished.void
startUnion(S2CellIndex.RangeIterator range)
Positions the ContentsIterator at the first (cellId, label) pair that covers the given leaf cell range.
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Field Detail
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DONE
private static final int DONE
A special label indicating thatdone()
is true.- See Also:
- Constant Field Values
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prevStartId
private S2CellId prevStartId
The value of it.startId() from the previous call to startUnion(). This is used to check whether these values are monotonically increasing.
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nodeCutoff
private int nodeCutoff
The maximum index withinS2CellIndex.cellNodes
visited during the previous call to startUnion(). This is used to eliminate duplicate values when startUnion() is called multiple times.
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nextNodeCutoff
private int nextNodeCutoff
The maximum index withinS2CellIndex.cellNodes
visited during the current call to startUnion(). This is used to update nodeCutoff.
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node
private final S2CellIndex.CellNode node
A copy of the current node in the cell tree.
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Constructor Detail
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ContentsIterator
private ContentsIterator()
Creates a new iterator. CallstartUnion(com.google.common.geometry.S2CellIndex.RangeIterator)
next.
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Method Detail
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clear
public void clear()
Clears all state with respect to which range(s) have been visited.
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startUnion
public void startUnion(S2CellIndex.RangeIterator range)
Positions the ContentsIterator at the first (cellId, label) pair that covers the given leaf cell range. Note that when multiple leaf cell ranges are visited using the same ContentsIterator, duplicate values may be suppressed. If you don't want this behavior, call clear() first.
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cellId
public S2CellId cellId()
Returns the S2CellId of the current (cellId, label) pair.
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label
public int label()
Returns the label of the current (cellId, label) pair.
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done
public boolean done()
Returns true if all (cellId, label) pairs have been visited.
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next
public void next()
Advances the iterator to the next (cellId, label) pair covered by the current leaf cell range.
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setDone
private void setDone()
Sets the current node label to DONE to indicate that iteration has finished.
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