This class has all the configuration of snapping and can return answers to snapping queries. More...

#include <qgssnappingutils.h>

Inheritance diagram for QgsSnappingUtils:

[legend]

Classes
struct	LayerConfig
	Configures how a certain layer should be handled in a snapping operation. More...

Public Types
enum	IndexingStrategy { IndexAlwaysFull , IndexNeverFull , IndexHybrid , IndexExtent }

Public Slots
void	setConfig (const QgsSnappingConfig &snappingConfig)
	The snapping configuration controls the behavior of this object.

void	toggleEnabled ()
	Toggles the state of snapping.

Signals
void	configChanged (const QgsSnappingConfig &snappingConfig)
	Emitted when the snapping settings object changes.

Public Member Functions
	QgsSnappingUtils (QObject *parent=nullptr, bool enableSnappingForInvisibleFeature=true)
	Constructor for QgsSnappingUtils.

	~QgsSnappingUtils () override

void	addExtraSnapLayer (QgsVectorLayer *vl)
	Supply an extra snapping layer (typically a memory layer).

QgsSnappingConfig	config () const
	The snapping configuration controls the behavior of this object.

QgsVectorLayer *	currentLayer () const
	The current layer used if mode is SnapCurrentLayer.

QString	dump ()
	Gets extra information about the instance.

QSet< QgsVectorLayer * >	getExtraSnapLayers ()
	Returns the list of extra snapping layers.

IndexingStrategy	indexingStrategy () const
	Find out which strategy is used for indexing - by default hybrid indexing is used.

QList< QgsSnappingUtils::LayerConfig >	layers () const
	Query layers used for snapping.

QgsPointLocator *	locatorForLayer (QgsVectorLayer *vl)
	Gets a point locator for the given layer.

QgsMapSettings	mapSettings () const

void	removeExtraSnapLayer (QgsVectorLayer *vl)
	Removes an extra snapping layer.

void	setCurrentLayer (QgsVectorLayer *layer)
	Sets current layer so that if mode is SnapCurrentLayer we know which layer to use.

void	setEnableSnappingForInvisibleFeature (bool enable)
	Set if invisible features must be snapped or not.

void	setIndexingStrategy (IndexingStrategy strategy)
	Sets a strategy for indexing geometry data - determines how fast and memory consuming the data structures will be.

void	setMapSettings (const QgsMapSettings &settings)
	Assign current map settings to the utils - used for conversion between screen coords to map coords.

QgsPointLocator::Match	snapToCurrentLayer (QPoint point, QgsPointLocator::Types type, QgsPointLocator::MatchFilter *filter=nullptr)
	Snap to current layer.

QgsPointLocator::Match	snapToMap (const QgsPointXY &pointMap, QgsPointLocator::MatchFilter *filter=nullptr, bool relaxed=false)
	Snap to map according to the current configuration.

QgsPointLocator::Match	snapToMap (QPoint point, QgsPointLocator::MatchFilter *filter=nullptr, bool relaxed=false)
	Snap to map according to the current configuration.

Protected Member Functions
void	clearAllLocators ()
	Deletes all existing locators (e.g. when destination CRS has changed and we need to reindex)

virtual void	prepareIndexProgress (int index)
	Called when finished indexing a layer with snapToMap. When index == count the indexing is complete.

virtual void	prepareIndexStarting (int count)
	Called when starting to index with snapToMap - can be overridden and e.g. progress dialog can be provided.

Properties
QgsSnappingConfig	config

Detailed Description

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).

Definition at line 49 of file qgssnappingutils.h.

Member Enumeration Documentation

◆ IndexingStrategy

enum QgsSnappingUtils::IndexingStrategy

Enumerator
IndexAlwaysFull	For all layers build index of full extent. Uses more memory, but queries are faster.
IndexNeverFull	For all layers only create temporary indexes of small extent. Low memory usage, slower queries.
IndexHybrid	For "big" layers using IndexNeverFull, for the rest IndexAlwaysFull. Compromise between speed and memory usage.
IndexExtent	For all layer build index of extent given in map settings.

Definition at line 105 of file qgssnappingutils.h.

Constructor & Destructor Documentation

◆ QgsSnappingUtils()

QgsSnappingUtils::QgsSnappingUtils	(	QObject *	parent = `nullptr`,
		bool	enableSnappingForInvisibleFeature = `true`
	)

Constructor for QgsSnappingUtils.

Parameters

parent	parent object
enableSnappingForInvisibleFeature	`true` if we want to snap feature even if there are not visible

Definition at line 24 of file qgssnappingutils.cpp.

◆ ~QgsSnappingUtils()

QgsSnappingUtils::~QgsSnappingUtils ( )

override

Definition at line 31 of file qgssnappingutils.cpp.

Member Function Documentation

◆ addExtraSnapLayer()

void QgsSnappingUtils::addExtraSnapLayer ( QgsVectorLayer * vl )

inline

Supply an extra snapping layer (typically a memory layer).

This can be used by map tools to provide additional snappings points.

See also: removeExtraSnapLayer(); getExtraSnapLayers()

Since: QGIS 3.14

Definition at line 200 of file qgssnappingutils.h.

◆ clearAllLocators()

void QgsSnappingUtils::clearAllLocators ( )

protected

Deletes all existing locators (e.g. when destination CRS has changed and we need to reindex)

Definition at line 51 of file qgssnappingutils.cpp.

◆ config()

QgsSnappingConfig QgsSnappingUtils::config ( ) const

The snapping configuration controls the behavior of this object.

Definition at line 541 of file qgssnappingutils.cpp.

◆ configChanged

void QgsSnappingUtils::configChanged ( const QgsSnappingConfig & snappingConfig )

signal

Emitted when the snapping settings object changes.

◆ currentLayer()

QgsVectorLayer * QgsSnappingUtils::currentLayer ( ) const

inline

The current layer used if mode is SnapCurrentLayer.

Definition at line 101 of file qgssnappingutils.h.

◆ dump()

QString QgsSnappingUtils::dump ( )

Gets extra information about the instance.

Definition at line 602 of file qgssnappingutils.cpp.

◆ getExtraSnapLayers()

QSet< QgsVectorLayer * > QgsSnappingUtils::getExtraSnapLayers ( )

inline

Returns the list of extra snapping layers.

See also: addExtraSnapLayer(); removeExtraSnapLayer()

Since: QGIS 3.14

Definition at line 226 of file qgssnappingutils.h.

◆ indexingStrategy()

IndexingStrategy QgsSnappingUtils::indexingStrategy ( ) const

inline

Find out which strategy is used for indexing - by default hybrid indexing is used.

Definition at line 116 of file qgssnappingutils.h.

◆ layers()

QList< QgsSnappingUtils::LayerConfig > QgsSnappingUtils::layers ( ) const

inline

Query layers used for snapping.

Definition at line 169 of file qgssnappingutils.h.

◆ locatorForLayer()

QgsPointLocator * QgsSnappingUtils::locatorForLayer ( QgsVectorLayer * vl )

Gets a point locator for the given layer.

If such locator does not exist, it will be created

Parameters

vl	the vector layer

Definition at line 37 of file qgssnappingutils.cpp.

◆ mapSettings()

QgsMapSettings QgsSnappingUtils::mapSettings ( ) const

inline

Definition at line 96 of file qgssnappingutils.h.

◆ prepareIndexProgress()

virtual void QgsSnappingUtils::prepareIndexProgress ( int index )

inlineprotectedvirtual

Called when finished indexing a layer with snapToMap. When index == count the indexing is complete.

Reimplemented in QgsMapCanvasSnappingUtils.

Definition at line 257 of file qgssnappingutils.h.

◆ prepareIndexStarting()

virtual void QgsSnappingUtils::prepareIndexStarting ( int count )

inlineprotectedvirtual

Called when starting to index with snapToMap - can be overridden and e.g. progress dialog can be provided.

Reimplemented in QgsMapCanvasSnappingUtils.

Definition at line 255 of file qgssnappingutils.h.

◆ removeExtraSnapLayer()

void QgsSnappingUtils::removeExtraSnapLayer ( QgsVectorLayer * vl )

inline

Removes an extra snapping layer.

See also: addExtraSnapLayer(); getExtraSnapLayers()

Since: QGIS 3.14

Definition at line 213 of file qgssnappingutils.h.

◆ setConfig

void QgsSnappingUtils::setConfig ( const QgsSnappingConfig & snappingConfig )

slot

The snapping configuration controls the behavior of this object.

Definition at line 551 of file qgssnappingutils.cpp.

◆ setCurrentLayer()

void QgsSnappingUtils::setCurrentLayer ( QgsVectorLayer * layer )

Sets current layer so that if mode is SnapCurrentLayer we know which layer to use.

Definition at line 597 of file qgssnappingutils.cpp.

◆ setEnableSnappingForInvisibleFeature()

void QgsSnappingUtils::setEnableSnappingForInvisibleFeature ( bool enable )

Set if invisible features must be snapped or not.

Parameters

enable Enable or not this feature

Since: QGIS 3.2

Definition at line 546 of file qgssnappingutils.cpp.

◆ setIndexingStrategy()

void QgsSnappingUtils::setIndexingStrategy ( IndexingStrategy strategy )

inline

Sets a strategy for indexing geometry data - determines how fast and memory consuming the data structures will be.

Definition at line 114 of file qgssnappingutils.h.

◆ setMapSettings()

void QgsSnappingUtils::setMapSettings ( const QgsMapSettings & settings )

Assign current map settings to the utils - used for conversion between screen coords to map coords.

Definition at line 587 of file qgssnappingutils.cpp.

◆ snapToCurrentLayer()

QgsPointLocator::Match QgsSnappingUtils::snapToCurrentLayer	(	QPoint	point,
		QgsPointLocator::Types	type,
		QgsPointLocator::MatchFilter *	filter = `nullptr`
	)

Snap to current layer.

Definition at line 570 of file qgssnappingutils.cpp.

◆ snapToMap() [1/2]

QgsPointLocator::Match QgsSnappingUtils::snapToMap	(	const QgsPointXY &	pointMap,
		QgsPointLocator::MatchFilter *	filter = `nullptr`,
		bool	relaxed = `false`
	)

Snap to map according to the current configuration.

Parameters

pointMap	point in map coordinates
filter	allows discarding unwanted matches.
relaxed	`true` if this method is non blocking and the matching result can be invalid while indexing

Definition at line 268 of file qgssnappingutils.cpp.

◆ snapToMap() [2/2]

QgsPointLocator::Match QgsSnappingUtils::snapToMap	(	QPoint	point,
		QgsPointLocator::MatchFilter *	filter = `nullptr`,
		bool	relaxed = `false`
	)

Snap to map according to the current configuration.

Parameters

point	point in canvas coordinates
filter	allows discarding unwanted matches.
relaxed	`true` if this method is non blocking and the matching result can be invalid while indexing

Definition at line 257 of file qgssnappingutils.cpp.

◆ toggleEnabled

void QgsSnappingUtils::toggleEnabled ( )

slot

Toggles the state of snapping.

Definition at line 564 of file qgssnappingutils.cpp.

Property Documentation

◆ config

QgsSnappingConfig QgsSnappingUtils::config

readwrite

Definition at line 53 of file qgssnappingutils.h.

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

/build/qgis-3.41.0+git20241201+3c143d501a8+99sid/src/core/qgssnappingutils.h
/build/qgis-3.41.0+git20241201+3c143d501a8+99sid/src/core/qgssnappingutils.cpp

Classes

Public Types

Public Slots

Signals

Public Member Functions

Protected Member Functions

Properties

Detailed Description

Member Enumeration Documentation

◆ IndexingStrategy

Constructor & Destructor Documentation

◆ QgsSnappingUtils()

◆ ~QgsSnappingUtils()

Member Function Documentation

◆ addExtraSnapLayer()

◆ clearAllLocators()

◆ config()

◆ configChanged

◆ currentLayer()

◆ dump()

◆ getExtraSnapLayers()

◆ indexingStrategy()

◆ layers()

◆ locatorForLayer()

◆ mapSettings()

◆ prepareIndexProgress()

◆ prepareIndexStarting()

◆ removeExtraSnapLayer()

◆ setConfig

◆ setCurrentLayer()

◆ setEnableSnappingForInvisibleFeature()

◆ setIndexingStrategy()

◆ setMapSettings()

◆ snapToCurrentLayer()

◆ snapToMap() [1/2]

◆ snapToMap() [2/2]

◆ toggleEnabled

Property Documentation

◆ config