QGIS API Documentation
3.10.0-A Coruña (6c816b4204)
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The class defines interface for querying point location: More...
#include <qgspointlocator.h>
Classes | |
struct | Match |
struct | MatchFilter |
Interface that allows rejection of some matches in intersection queries (e.g. More... | |
Public Types | |
typedef class QList< QgsPointLocator::Match > | MatchList |
enum | Type { Invalid = 0, Vertex = 1, Edge = 2, Area = 4, All = Vertex | Edge | Area } |
The type of a snap result or the filter type for a snap request. More... | |
Public Member Functions | |
QgsPointLocator (QgsVectorLayer *layer, const QgsCoordinateReferenceSystem &destinationCrs=QgsCoordinateReferenceSystem(), const QgsCoordinateTransformContext &transformContext=QgsCoordinateTransformContext(), const QgsRectangle *extent=nullptr) | |
Construct point locator for a layer. More... | |
~QgsPointLocator () override | |
int | cachedGeometryCount () const |
Returns how many geometries are cached in the index. More... | |
QgsCoordinateReferenceSystem | destinationCrs () const |
Gets destination CRS - may be an invalid QgsCoordinateReferenceSystem if not doing OTF reprojection. More... | |
MatchList | edgesInRect (const QgsRectangle &rect, QgsPointLocator::MatchFilter *filter=nullptr) |
Find edges within a specified recangle Optional filter may discard unwanted matches. More... | |
MatchList | edgesInRect (const QgsPointXY &point, double tolerance, QgsPointLocator::MatchFilter *filter=nullptr) |
Override of edgesInRect that construct rectangle from a center point and tolerance. More... | |
const QgsRectangle * | extent () const |
Gets extent of the area point locator covers - if nullptr then it caches the whole layer. More... | |
bool | hasIndex () const |
Indicate whether the data have been already indexed. More... | |
bool | init (int maxFeaturesToIndex=-1) |
Prepare the index for queries. More... | |
QgsVectorLayer * | layer () const |
Gets associated layer. More... | |
Match | nearestArea (const QgsPointXY &point, double tolerance, QgsPointLocator::MatchFilter *filter=nullptr) |
Find nearest area to the specified point - up to distance specified by tolerance Optional filter may discard unwanted matches. More... | |
Match | nearestEdge (const QgsPointXY &point, double tolerance, QgsPointLocator::MatchFilter *filter=nullptr) |
Find nearest edge to the specified point - up to distance specified by tolerance Optional filter may discard unwanted matches. More... | |
Match | nearestVertex (const QgsPointXY &point, double tolerance, QgsPointLocator::MatchFilter *filter=nullptr) |
Find nearest vertex to the specified point - up to distance specified by tolerance Optional filter may discard unwanted matches. More... | |
MatchList | pointInPolygon (const QgsPointXY &point) |
find out if the point is in any polygons More... | |
void | setExtent (const QgsRectangle *extent) |
Configure extent - if not nullptr , it will index only that area. More... | |
void | setRenderContext (const QgsRenderContext *context) |
Configure render context - if not nullptr , it will use to index only visible feature. More... | |
MatchList | verticesInRect (const QgsRectangle &rect, QgsPointLocator::MatchFilter *filter=nullptr) |
Find vertices within a specified recangle Optional filter may discard unwanted matches. More... | |
MatchList | verticesInRect (const QgsPointXY &point, double tolerance, QgsPointLocator::MatchFilter *filter=nullptr) |
Override of verticesInRect that construct rectangle from a center point and tolerance. More... | |
Protected Slots | |
void | destroyIndex () |
Protected Member Functions | |
bool | rebuildIndex (int maxFeaturesToIndex=-1) |
Friends | |
class | QgsPointLocator_VisitorArea |
class | QgsPointLocator_VisitorEdgesInRect |
class | QgsPointLocator_VisitorNearestEdge |
class | QgsPointLocator_VisitorNearestVertex |
class | QgsPointLocator_VisitorVerticesInRect |
The class defines interface for querying point location:
Works with one layer.
Definition at line 55 of file qgspointlocator.h.
typedef class QList< QgsPointLocator::Match > QgsPointLocator::MatchList |
Definition at line 213 of file qgspointlocator.h.
The type of a snap result or the filter type for a snap request.
Enumerator | |
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Invalid | Invalid. |
Vertex | Snapped to a vertex. Can be a vertex of the geometry or an intersection. |
Edge | Snapped to an edge. |
Area | Snapped to an area. |
All | Combination of vertex, edge and area. |
Definition at line 109 of file qgspointlocator.h.
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explicit |
Construct point locator for a layer.
If a valid QgsCoordinateReferenceSystem is passed for destinationCrs then the locator will do the searches on data reprojected to the given CRS. For accurate reprojection it is important to set the correct transformContext if a destinationCrs is specified. This is usually taken from the current QgsProject::transformContext().
If extent is not nullptr
, the locator will index only a subset of the layer which falls within that extent.
Definition at line 525 of file qgspointlocator.cpp.
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override |
Definition at line 545 of file qgspointlocator.cpp.
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inline |
Returns how many geometries are cached in the index.
Definition at line 283 of file qgspointlocator.h.
QgsCoordinateReferenceSystem QgsPointLocator::destinationCrs | ( | ) | const |
Gets destination CRS - may be an invalid QgsCoordinateReferenceSystem if not doing OTF reprojection.
Definition at line 550 of file qgspointlocator.cpp.
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protectedslot |
Definition at line 717 of file qgspointlocator.cpp.
QgsPointLocator::MatchList QgsPointLocator::edgesInRect | ( | const QgsRectangle & | rect, |
QgsPointLocator::MatchFilter * | filter = nullptr |
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Find edges within a specified recangle Optional filter may discard unwanted matches.
Definition at line 903 of file qgspointlocator.cpp.
QgsPointLocator::MatchList QgsPointLocator::edgesInRect | ( | const QgsPointXY & | point, |
double | tolerance, | ||
QgsPointLocator::MatchFilter * | filter = nullptr |
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Override of edgesInRect that construct rectangle from a center point and tolerance.
Definition at line 923 of file qgspointlocator.cpp.
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inline |
Gets extent of the area point locator covers - if nullptr
then it caches the whole layer.
Definition at line 92 of file qgspointlocator.h.
bool QgsPointLocator::hasIndex | ( | ) | const |
Indicate whether the data have been already indexed.
Definition at line 583 of file qgspointlocator.cpp.
bool QgsPointLocator::init | ( | int | maxFeaturesToIndex = -1 | ) |
Prepare the index for queries.
Does nothing if the index already exists. If the number of features is greater than the value of maxFeaturesToIndex, creation of index is stopped to make sure we do not run out of memory. If maxFeaturesToIndex is -1, no limits are used. Returns false
if the creation of index has been prematurely stopped due to the limit of features, otherwise true
Definition at line 577 of file qgspointlocator.cpp.
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inline |
QgsPointLocator::Match QgsPointLocator::nearestArea | ( | const QgsPointXY & | point, |
double | tolerance, | ||
QgsPointLocator::MatchFilter * | filter = nullptr |
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Find nearest area to the specified point - up to distance specified by tolerance Optional filter may discard unwanted matches.
This will first perform a pointInPolygon and return first result. If no match is found and tolerance is not 0, it will return nearestEdge.
Definition at line 869 of file qgspointlocator.cpp.
QgsPointLocator::Match QgsPointLocator::nearestEdge | ( | const QgsPointXY & | point, |
double | tolerance, | ||
QgsPointLocator::MatchFilter * | filter = nullptr |
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Find nearest edge to the specified point - up to distance specified by tolerance Optional filter may discard unwanted matches.
Definition at line 847 of file qgspointlocator.cpp.
QgsPointLocator::Match QgsPointLocator::nearestVertex | ( | const QgsPointXY & | point, |
double | tolerance, | ||
QgsPointLocator::MatchFilter * | filter = nullptr |
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Find nearest vertex to the specified point - up to distance specified by tolerance Optional filter may discard unwanted matches.
Definition at line 829 of file qgspointlocator.cpp.
QgsPointLocator::MatchList QgsPointLocator::pointInPolygon | ( | const QgsPointXY & | point | ) |
find out if the point is in any polygons
Definition at line 952 of file qgspointlocator.cpp.
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protected |
Definition at line 589 of file qgspointlocator.cpp.
void QgsPointLocator::setExtent | ( | const QgsRectangle * | extent | ) |
Configure extent - if not nullptr
, it will index only that area.
Definition at line 555 of file qgspointlocator.cpp.
void QgsPointLocator::setRenderContext | ( | const QgsRenderContext * | context | ) |
Configure render context - if not nullptr
, it will use to index only visible feature.
Definition at line 562 of file qgspointlocator.cpp.
QgsPointLocator::MatchList QgsPointLocator::verticesInRect | ( | const QgsRectangle & | rect, |
QgsPointLocator::MatchFilter * | filter = nullptr |
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Find vertices within a specified recangle Optional filter may discard unwanted matches.
Definition at line 929 of file qgspointlocator.cpp.
QgsPointLocator::MatchList QgsPointLocator::verticesInRect | ( | const QgsPointXY & | point, |
double | tolerance, | ||
QgsPointLocator::MatchFilter * | filter = nullptr |
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Override of verticesInRect that construct rectangle from a center point and tolerance.
Definition at line 945 of file qgspointlocator.cpp.
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friend |
Definition at line 315 of file qgspointlocator.h.
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friend |
Definition at line 316 of file qgspointlocator.h.
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friend |
Definition at line 314 of file qgspointlocator.h.
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friend |
Definition at line 313 of file qgspointlocator.h.
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friend |
Definition at line 317 of file qgspointlocator.h.