Subgroup: Point
Class: QgsPointLocator¶
-
class
qgis.core.
QgsPointLocator
(layer: QgsVectorLayer, destinationCrs: QgsCoordinateReferenceSystem = QgsCoordinateReferenceSystem(), transformContext: QgsCoordinateTransformContext = QgsCoordinateTransformContext(), extent: QgsRectangle = None)¶ Bases:
PyQt5.QtCore.QObject
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 correcttransformContext
if adestinationCrs
is specified. This is usually taken from the currentQgsProject.transformContext()
If
extent
is not null, the locator will index only a subset of the layer which falls within that extent.The class defines interface for querying point location:- query nearest vertices / edges to a point
- query vertices / edges in rectangle
- query areas covering a point
Works with one layer.
New in version 2.8: Methods
cachedGeometryCount
Return how many geometries are cached in the index childEvent
connectNotify
customEvent
destinationCrs
Get destination CRS - may be an invalid QgsCoordinateReferenceSystem if not doing OTF reprojection destroyIndex
disconnectNotify
edgesInRect
Find edges within a specified recangle Optional filter may discard unwanted matches. extent
Get extent of the area point locator covers - if null then it caches the whole layer hasIndex
Indicate whether the data have been already indexed init
Prepare the index for queries. isSignalConnected
layer
Get associated layer nearestArea
Find nearest area to the specified point - up to distance specified by tolerance Optional filter may discard unwanted matches. nearestEdge
Find nearest edge to the specified point - up to distance specified by tolerance Optional filter may discard unwanted matches. nearestVertex
Find nearest vertex to the specified point - up to distance specified by tolerance Optional filter may discard unwanted matches. pointInPolygon
find out if the point is in any polygons rebuildIndex
receivers
sender
senderSignalIndex
setExtent
Configure extent - if not null, it will index only that area timerEvent
Signals
Attributes
All
Area
Edge
Invalid
Vertex
-
All
= 7¶
-
Area
= 4¶
-
Edge
= 2¶
-
Invalid
= 0¶
-
class
Match
¶ Bases:
sip.wrapper
construct invalid match
QgsPointLocator.Match(t: QgsPointLocator.Type, vl: QgsVectorLayer, fid: int, dist: float, pt: QgsPointXY, vertexIndex: int = 0, edgePoints: QgsPointXY = None)
QgsPointLocator.Match(QgsPointLocator.Match)
-
distance
(self) → float¶ for vertex / edge match units depending on what class returns it (geom.cache: layer units, map canvas snapper: dest crs units)
-
edgePoints
(self) → Tuple[QgsPointXY, QgsPointXY]¶ Only for a valid edge match - obtain endpoints of the edge
-
featureId
(self) → int¶ The id of the feature to which the snapped geometry belongs.
-
hasArea
(self) → bool¶
-
hasEdge
(self) → bool¶
-
hasVertex
(self) → bool¶
-
isValid
(self) → bool¶
-
layer
(self) → QgsVectorLayer¶ The vector layer where the snap occurred. Will be null if the snap happened on an intersection.
-
point
(self) → QgsPointXY¶ for vertex / edge match coords depending on what class returns it (geom.cache: layer coords, map canvas snapper: dest coords)
-
type
(self) → QgsPointLocator.Type¶
-
vertexIndex
(self) → int¶ for vertex / edge match (first vertex of the edge)
-
-
class
MatchFilter
¶ Bases:
sip.wrapper
QgsPointLocator.MatchFilter(QgsPointLocator.MatchFilter)
-
acceptMatch
(self, match: QgsPointLocator.Match) → bool¶
-
-
class
Type
¶ Bases:
int
-
class
Types
¶ Bases:
sip.wrapper
QgsPointLocator.Types(Union[QgsPointLocator.Types, QgsPointLocator.Type]) QgsPointLocator.Types(QgsPointLocator.Types)
-
Vertex
= 1¶
-
cachedGeometryCount
(self) → int¶ Return how many geometries are cached in the index
New in version 2.14.
-
childEvent
()¶
-
connectNotify
()¶
-
customEvent
()¶
-
destinationCrs
(self) → QgsCoordinateReferenceSystem¶ Get destination CRS - may be an invalid QgsCoordinateReferenceSystem if not doing OTF reprojection
New in version 2.14.
-
destroyIndex
(self)¶
-
disconnectNotify
()¶
-
edgesInRect
(self, rect: QgsRectangle, filter: QgsPointLocator.MatchFilter = None) → object¶ Find edges within a specified recangle Optional filter may discard unwanted matches.
edgesInRect(self, point: QgsPointXY, tolerance: float, filter: QgsPointLocator.MatchFilter = None) -> object Override of edgesInRect that construct rectangle from a center point and tolerance
-
extent
(self) → QgsRectangle¶ Get extent of the area point locator covers - if null then it caches the whole layer
New in version 2.14.
-
hasIndex
(self) → bool¶ Indicate whether the data have been already indexed
-
init
(self, maxFeaturesToIndex: int = -1) → bool¶ 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 *
-
isSignalConnected
()¶
-
layer
(self) → QgsVectorLayer¶ Get associated layer
New in version 2.14.
-
nearestArea
(self, point: QgsPointXY, tolerance: float, filter: QgsPointLocator.MatchFilter = None) → QgsPointLocator.Match¶ 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.
New in version 3.0.
-
nearestEdge
(self, point: QgsPointXY, tolerance: float, filter: QgsPointLocator.MatchFilter = None) → QgsPointLocator.Match¶ Find nearest edge to the specified point - up to distance specified by tolerance Optional filter may discard unwanted matches.
-
nearestVertex
(self, point: QgsPointXY, tolerance: float, filter: QgsPointLocator.MatchFilter = None) → QgsPointLocator.Match¶ Find nearest vertex to the specified point - up to distance specified by tolerance Optional filter may discard unwanted matches.
-
pointInPolygon
(self, point: QgsPointXY) → object¶ find out if the point is in any polygons
-
rebuildIndex
(self, maxFeaturesToIndex: int = -1) → bool¶
-
receivers
()¶
-
sender
()¶
-
senderSignalIndex
()¶
-
setExtent
(self, extent: QgsRectangle)¶ Configure extent - if not null, it will index only that area
New in version 2.14.
-
timerEvent
()¶