Class: QgsSnappingUtils¶
-
class
qgis.core.
QgsSnappingUtils
(parent: QObject = None, enableSnappingForInvisibleFeature: bool = True)¶ Bases:
PyQt5.QtCore.QObject
Constructor for QgsSnappingUtils
This class has all the configuration of snapping and can return answers to snapping queries. Internally, it keeps a cache of QgsPointLocator instances for multiple layers.
Currently it supports the following queries: - snapToMap() - has multiple modes of operation - snapToCurrentLayer() For more complex queries it is possible to use locatorForLayer() method that returns point locator instance with layer’s indexed data.
Indexing strategy determines how fast the queries will be and how much memory will be used.
When working with map canvas, it may be useful to use derived class QgsMapCanvasSnappingUtils which keeps the configuration in sync with map canvas (e.g. current view, active layer).
New in version 2.8: Enums
Methods
Deletes all existing locators (e.g.
The snapping configuration controls the behavior of this object
The current layer used if mode is SnapCurrentLayer
Gets extra information about the instance
Find out which strategy is used for indexing - by default hybrid indexing is used
Query layers used for snapping
Gets a point locator for the given layer.
Called when finished indexing a layer.
Called when starting to index - can be overridden and e.g.
The snapping configuration controls the behavior of this object
Sets current layer so that if mode is SnapCurrentLayer we know which layer to use
Set if invisible features must be snapped or not.
Sets a strategy for indexing geometry data - determines how fast and memory consuming the data structures will be
Assign current map settings to the utils - used for conversion between screen coords to map coords
Snap to current layer
Snap to map according to the current configuration.
Toggles the state of snapping
Signals
Emitted when the snapping settings object changes.
Attributes
-
IndexAlwaysFull
= 0¶
-
IndexExtent
= 3¶
-
IndexHybrid
= 2¶
-
IndexNeverFull
= 1¶
-
class
IndexingStrategy
¶ Bases:
int
-
class
LayerConfig
(l: QgsVectorLayer, t: Union[QgsPointLocator.Types, QgsPointLocator.Type], tol: float, u: QgsTolerance.UnitType)¶ Bases:
sip.wrapper
Create a new configuration for a snapping layer.
```py snapper = QgsMapCanvasSnappingUtils(mapCanvas)
snapping_layer1 = QgsSnappingUtils.LayerConfig(layer1, QgsPointLocator.Vertex, 10, QgsTolerance.Pixels) snapping_layer2 = QgsSnappingUtils.LayerConfig(layer2, QgsPointLocator.Vertex and QgsPointLocator.Edge, 10, QgsTolerance.Pixels)
snapper.setLayers([snapping_layer1, snapping_layer2]) ```
- Parameters
l – The vector layer for which this configuration is
t – Which parts of the geometry should be snappable
tol – The tolerance radius in which the snapping will trigger
u – The unit in which the tolerance is specified
QgsSnappingUtils.LayerConfig(QgsSnappingUtils.LayerConfig)
-
layer
¶
-
tolerance
¶
-
type
¶
-
unit
¶
-
childEvent
()¶
-
clearAllLocators
(self)¶ Deletes all existing locators (e.g. when destination CRS has changed and we need to reindex)
-
config
(self) → QgsSnappingConfig¶ The snapping configuration controls the behavior of this object
-
configChanged
¶ Emitted when the snapping settings object changes. [signal]
-
connectNotify
()¶
-
currentLayer
(self) → QgsVectorLayer¶ The current layer used if mode is SnapCurrentLayer
-
customEvent
()¶
-
disconnectNotify
()¶
-
dump
(self) → str¶ Gets extra information about the instance
New in version 2.14.
-
indexingStrategy
(self) → QgsSnappingUtils.IndexingStrategy¶ Find out which strategy is used for indexing - by default hybrid indexing is used
-
isSignalConnected
()¶
-
layers
(self) → object¶ Query layers used for snapping
-
locatorForLayer
(self, vl: QgsVectorLayer) → QgsPointLocator¶ Gets a point locator for the given layer. If such locator does not exist, it will be created
-
mapSettings
(self) → QgsMapSettings¶
-
prepareIndexProgress
(self, index: int)¶ Called when finished indexing a layer. When index == count the indexing is complete
-
prepareIndexStarting
(self, count: int)¶ Called when starting to index - can be overridden and e.g. progress dialog can be provided
-
receivers
()¶
-
sender
()¶
-
senderSignalIndex
()¶
-
setConfig
(self, snappingConfig: QgsSnappingConfig)¶ The snapping configuration controls the behavior of this object
-
setCurrentLayer
(self, layer: QgsVectorLayer)¶ Sets current layer so that if mode is SnapCurrentLayer we know which layer to use
-
setEnableSnappingForInvisibleFeature
(self, enable: bool)¶ Set if invisible features must be snapped or not.
- Parameters
enable – Enable or not this feature
New in version 3.2.
-
setIndexingStrategy
(self, strategy: QgsSnappingUtils.IndexingStrategy)¶ Sets a strategy for indexing geometry data - determines how fast and memory consuming the data structures will be
-
setMapSettings
(self, settings: QgsMapSettings)¶ Assign current map settings to the utils - used for conversion between screen coords to map coords
-
snapToCurrentLayer
(self, point: QPoint, type: Union[QgsPointLocator.Types, QgsPointLocator.Type], filter: QgsPointLocator.MatchFilter = None) → QgsPointLocator.Match¶ Snap to current layer
-
snapToMap
(self, point: QPoint, filter: QgsPointLocator.MatchFilter = None) → QgsPointLocator.Match¶ Snap to map according to the current configuration. Optional filter allows discarding unwanted matches.
snapToMap(self, pointMap: QgsPointXY, filter: QgsPointLocator.MatchFilter = None) -> QgsPointLocator.Match
-
timerEvent
()¶
-
toggleEnabled
(self)¶ Toggles the state of snapping
New in version 3.0.
-