QGIS API Documentation  2.99.0-Master (6c64c5a)
Public Member Functions | Friends | List of all members
QgsSpatialIndex Class Reference

A spatial index for QgsFeature objects. More...

#include <qgsspatialindex.h>

Public Member Functions

 QgsSpatialIndex ()
 Constructor for QgsSpatialIndex. More...
 
 QgsSpatialIndex (const QgsFeatureIterator &fi, QgsFeedback *feedback=nullptr)
 Constructor - creates R-tree and bulk loads it with features from the iterator. More...
 
 QgsSpatialIndex (const QgsFeatureSource &source, QgsFeedback *feedback=nullptr)
 Constructor - creates R-tree and bulk loads it with features from the source. More...
 
 QgsSpatialIndex (const QgsSpatialIndex &other)
 Copy constructor. More...
 
 ~QgsSpatialIndex ()
 Destructor finalizes work with spatial index. More...
 
bool deleteFeature (const QgsFeature &feature)
 Removes a feature from the index. More...
 
bool insertFeature (const QgsFeature &feature)
 Adds a feature to the index. More...
 
bool insertFeature (QgsFeatureId id, const QgsRectangle &bounds)
 Add a feature id to the index with a specified bounding box. More...
 
QList< QgsFeatureIdintersects (const QgsRectangle &rectangle) const
 Returns a list of features with a bounding box which intersects the specified rectangle. More...
 
QList< QgsFeatureIdnearestNeighbor (const QgsPointXY &point, int neighbors) const
 Returns nearest neighbors to a point. More...
 
QgsSpatialIndexoperator= (const QgsSpatialIndex &other)
 Implement assignment operator. More...
 
QAtomicInt refs () const
 get reference count - just for debugging! More...
 

Friends

class QgsFeatureIteratorDataStream
 

Detailed Description

A spatial index for QgsFeature objects.

QgsSpatialIndex objects are implicitly shared and can be inexpensively copied.

Note
While the underlying libspatialindex is not thread safe on some platforms, the QgsSpatialIndex class implements its own locks and accordingly, a single QgsSpatialIndex object can safely be used across multiple threads.

Definition at line 64 of file qgsspatialindex.h.

Constructor & Destructor Documentation

◆ QgsSpatialIndex() [1/4]

QgsSpatialIndex::QgsSpatialIndex ( )

Constructor for QgsSpatialIndex.

Creates an empty R-tree index.

Definition at line 244 of file qgsspatialindex.cpp.

◆ QgsSpatialIndex() [2/4]

QgsSpatialIndex::QgsSpatialIndex ( const QgsFeatureIterator fi,
QgsFeedback feedback = nullptr 
)
explicit

Constructor - creates R-tree and bulk loads it with features from the iterator.

This is much faster approach than creating an empty index and then inserting features one by one.

The optional feedback object can be used to allow cancelation of bulk feature loading. Ownership of feedback is not transferred, and callers must take care that the lifetime of feedback exceeds that of the spatial index construction.

Since
QGIS 2.8

Definition at line 249 of file qgsspatialindex.cpp.

◆ QgsSpatialIndex() [3/4]

QgsSpatialIndex::QgsSpatialIndex ( const QgsFeatureSource source,
QgsFeedback feedback = nullptr 
)
explicit

Constructor - creates R-tree and bulk loads it with features from the source.

This is much faster approach than creating an empty index and then inserting features one by one.

The optional feedback object can be used to allow cancelation of bulk feature loading. Ownership of feedback is not transferred, and callers must take care that the lifetime of feedback exceeds that of the spatial index construction.

Since
QGIS 3.0

Definition at line 254 of file qgsspatialindex.cpp.

◆ QgsSpatialIndex() [4/4]

QgsSpatialIndex::QgsSpatialIndex ( const QgsSpatialIndex other)

Copy constructor.

Definition at line 259 of file qgsspatialindex.cpp.

◆ ~QgsSpatialIndex()

QgsSpatialIndex::~QgsSpatialIndex ( )

Destructor finalizes work with spatial index.

Definition at line 264 of file qgsspatialindex.cpp.

Member Function Documentation

◆ deleteFeature()

bool QgsSpatialIndex::deleteFeature ( const QgsFeature feature)

Removes a feature from the index.

Definition at line 342 of file qgsspatialindex.cpp.

◆ insertFeature() [1/2]

bool QgsSpatialIndex::insertFeature ( const QgsFeature feature)

Adds a feature to the index.

Definition at line 302 of file qgsspatialindex.cpp.

◆ insertFeature() [2/2]

bool QgsSpatialIndex::insertFeature ( QgsFeatureId  id,
const QgsRectangle bounds 
)

Add a feature id to the index with a specified bounding box.

Returns
true if feature was successfully added to index.
Since
QGIS 3.0

Definition at line 312 of file qgsspatialindex.cpp.

◆ intersects()

QList< QgsFeatureId > QgsSpatialIndex::intersects ( const QgsRectangle rectangle) const

Returns a list of features with a bounding box which intersects the specified rectangle.

Note
The intersection test is performed based on the feature bounding boxes only, so for non-point geometry features it is necessary to manually test the returned features for exact geometry intersection when required.

Definition at line 354 of file qgsspatialindex.cpp.

◆ nearestNeighbor()

QList< QgsFeatureId > QgsSpatialIndex::nearestNeighbor ( const QgsPointXY point,
int  neighbors 
) const

Returns nearest neighbors to a point.

The number of neighbours returned is specified by the neighbours argument.

Note
The nearest neighbour test is performed based on the feature bounding boxes only, so for non-point geometry features this method is not guaranteed to return the actual closest neighbours.

Definition at line 367 of file qgsspatialindex.cpp.

◆ operator=()

QgsSpatialIndex & QgsSpatialIndex::operator= ( const QgsSpatialIndex other)

Implement assignment operator.

Definition at line 268 of file qgsspatialindex.cpp.

◆ refs()

QAtomicInt QgsSpatialIndex::refs ( ) const

get reference count - just for debugging!

Definition at line 381 of file qgsspatialindex.cpp.

Friends And Related Function Documentation

◆ QgsFeatureIteratorDataStream

friend class QgsFeatureIteratorDataStream
friend

Definition at line 180 of file qgsspatialindex.h.


The documentation for this class was generated from the following files: