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

#include <qgssnappingutils.h>

Inheritance diagram for QgsSnappingUtils:

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

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

enum	SnapToMapMode { SnapCurrentLayer, SnapAllLayers, SnapAdvanced }
	modes for "snap to background" More...

Public Slots
void	readConfigFromProject ()
	Read snapping configuration from the project. More...

Signals
void	configChanged ()
	Emitted when snapping configuration has been changed. More...

Public Member Functions
	QgsSnappingUtils (QObject *parent=nullptr)

	~QgsSnappingUtils ()

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

void	defaultSettings (int &type, double &tolerance, QgsTolerance::UnitType &unit)
	Query options used when the mode is snap to current layer or to all layers. More...

QString	dump ()
	Get extra information about the instance. More...

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

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

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

const QgsMapSettings &	mapSettings () const

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

void	setDefaultSettings (int type, double tolerance, QgsTolerance::UnitType unit)
	Configure options used when the mode is snap to current layer or to all layers. More...

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

void	setLayers (const QList< LayerConfig > &layers)
	Set layers which will be used for snapping. More...

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

void	setSnapOnIntersections (bool enabled)
	Set whether to consider intersections of nearby segments for snapping. More...

void	setSnapToMapMode (SnapToMapMode mode)
	Set how the snapping to map is done. More...

bool	snapOnIntersections () const
	Query whether to consider intersections of nearby segments for snapping. More...

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

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

QgsPointLocator::Match	snapToMap (const QgsPoint &pointMap, QgsPointLocator::MatchFilter *filter=nullptr)

SnapToMapMode	snapToMapMode () const
	Find out how the snapping to map is done. More...

Public Member Functions inherited from QObject
	QObject (QObject *parent)

	QObject (QObject parent, const char name)

virtual	~QObject ()

bool	blockSignals (bool block)

QObject *	child (const char objName, const char inheritsClass, bool recursiveSearch) const

const QObjectList &	children () const

const char *	className () const

bool	connect (const QObject sender, const char signal, const char *method, Qt::ConnectionType type) const

void	deleteLater ()

void	destroyed (QObject *obj)

bool	disconnect (const QObject receiver, const char method)

bool	disconnect (const char signal, const QObject receiver, const char *method)

void	dumpObjectInfo ()

void	dumpObjectTree ()

QList< QByteArray >	dynamicPropertyNames () const

virtual bool	event (QEvent *e)

virtual bool	eventFilter (QObject watched, QEvent event)

T	findChild (const QString &name) const

QList< T >	findChildren (const QRegExp &regExp) const

QList< T >	findChildren (const QString &name) const

bool	inherits (const char *className) const

void	insertChild (QObject *object)

void	installEventFilter (QObject *filterObj)

bool	isA (const char *className) const

bool	isWidgetType () const

void	killTimer (int id)

virtual const QMetaObject *	metaObject () const

void	moveToThread (QThread *targetThread)

const char *	name () const

const char *	name (const char *defaultName) const

QString	objectName () const

QObject *	parent () const

QVariant	property (const char *name) const

void	removeChild (QObject *object)

void	removeEventFilter (QObject *obj)

void	setName (const char *name)

void	setObjectName (const QString &name)

void	setParent (QObject *parent)

bool	setProperty (const char *name, const QVariant &value)

bool	signalsBlocked () const

int	startTimer (int interval)

QThread *	thread () const

Protected Member Functions
virtual void	prepareIndexProgress (int index)
	Called when finished indexing a layer. When index == count the indexing is complete. More...

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

Protected Member Functions inherited from QObject
bool	checkConnectArgs (const char signal, const QObject object, const char *method)

virtual void	childEvent (QChildEvent *event)

virtual void	connectNotify (const char *signal)

virtual void	customEvent (QEvent *event)

virtual void	disconnectNotify (const char *signal)

int	receivers (const char *signal) const

QObject *	sender () const

int	senderSignalIndex () const

virtual void	timerEvent (QTimerEvent *event)

Additional Inherited Members
Static Public Member Functions inherited from QObject
bool	connect (const QObject sender, const char signal, const QObject receiver, const char method, Qt::ConnectionType type)

bool	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type)

bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char method)

bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method)

QString	tr (const char sourceText, const char disambiguation, int n)

QString	trUtf8 (const char sourceText, const char disambiguation, int n)

Static Protected Member Functions inherited from QObject
QByteArray	normalizeSignalSlot (const char *signalSlot)

Properties inherited from QObject
	objectName

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).

Note: added in 2.8

Definition at line 41 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 87 of file qgssnappingutils.h.

◆ SnapToMapMode

enum QgsSnappingUtils::SnapToMapMode

modes for "snap to background"

Enumerator
SnapCurrentLayer	snap just to current layer (tolerance and type from defaultSettings())
SnapAllLayers	snap to all rendered layers (tolerance and type from defaultSettings())
SnapAdvanced	snap according to the configuration set in setLayers()

Definition at line 75 of file qgssnappingutils.h.

Constructor & Destructor Documentation

◆ QgsSnappingUtils()

QgsSnappingUtils::QgsSnappingUtils ( QObject * parent = nullptr )

Definition at line 24 of file qgssnappingutils.cpp.

◆ ~QgsSnappingUtils()

QgsSnappingUtils::~QgsSnappingUtils ( )

Definition at line 39 of file qgssnappingutils.cpp.

Member Function Documentation

◆ configChanged

void QgsSnappingUtils::configChanged ( )

signal

Emitted when snapping configuration has been changed.

Note: added in QGIS 2.14

◆ currentLayer()

QgsVectorLayer* QgsSnappingUtils::currentLayer ( ) const

inline

The current layer used if mode is SnapCurrentLayer.

Definition at line 69 of file qgssnappingutils.h.

◆ defaultSettings()

void QgsSnappingUtils::defaultSettings	(	int &	type,
		double &	tolerance,
		QgsTolerance::UnitType &	unit
	)

Query options used when the mode is snap to current layer or to all layers.

Definition at line 476 of file qgssnappingutils.cpp.

◆ dump()

QString QgsSnappingUtils::dump ( )

Get extra information about the instance.

Note: added in QGIS 2.14

Definition at line 502 of file qgssnappingutils.cpp.

◆ indexingStrategy()

IndexingStrategy QgsSnappingUtils::indexingStrategy ( ) const

inline

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

Definition at line 98 of file qgssnappingutils.h.

◆ layers()

QList<LayerConfig> QgsSnappingUtils::layers ( ) const

inline

Query layers used for snapping.

Definition at line 157 of file qgssnappingutils.h.

◆ locatorForLayer()

QgsPointLocator * QgsSnappingUtils::locatorForLayer ( QgsVectorLayer * vl )

Get a point locator for the given layer.

If such locator does not exist, it will be created

Definition at line 45 of file qgssnappingutils.cpp.

◆ mapSettings()

const QgsMapSettings& QgsSnappingUtils::mapSettings ( ) const

inline

Definition at line 64 of file qgssnappingutils.h.

◆ prepareIndexProgress()

virtual void QgsSnappingUtils::prepareIndexProgress ( int index )

inlineprotectedvirtual

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

Reimplemented in QgsMapCanvasSnappingUtils.

Definition at line 183 of file qgssnappingutils.h.

◆ prepareIndexStarting()

virtual void QgsSnappingUtils::prepareIndexStarting ( int count )

inlineprotectedvirtual

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

Reimplemented in QgsMapCanvasSnappingUtils.

Definition at line 181 of file qgssnappingutils.h.

◆ readConfigFromProject

void QgsSnappingUtils::readConfigFromProject ( )

slot

Read snapping configuration from the project.

Definition at line 589 of file qgssnappingutils.cpp.

◆ setCurrentLayer()

void QgsSnappingUtils::setCurrentLayer ( QgsVectorLayer * layer )

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

Definition at line 445 of file qgssnappingutils.cpp.

◆ setDefaultSettings()

void QgsSnappingUtils::setDefaultSettings	(	int	type,
		double	tolerance,
		QgsTolerance::UnitType	unit
	)

Configure options used when the mode is snap to current layer or to all layers.

Definition at line 459 of file qgssnappingutils.cpp.

◆ setIndexingStrategy()

void QgsSnappingUtils::setIndexingStrategy ( IndexingStrategy strategy )

inline

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

Definition at line 96 of file qgssnappingutils.h.

◆ setLayers()

void QgsSnappingUtils::setLayers ( const QList< LayerConfig > & layers )

Set layers which will be used for snapping.

Definition at line 483 of file qgssnappingutils.cpp.

◆ 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 435 of file qgssnappingutils.cpp.

◆ setSnapOnIntersections()

void QgsSnappingUtils::setSnapOnIntersections ( bool enabled )

Set whether to consider intersections of nearby segments for snapping.

Definition at line 493 of file qgssnappingutils.cpp.

◆ setSnapToMapMode()

void QgsSnappingUtils::setSnapToMapMode ( QgsSnappingUtils::SnapToMapMode mode )

Set how the snapping to map is done.

Definition at line 450 of file qgssnappingutils.cpp.

◆ snapOnIntersections()

bool QgsSnappingUtils::snapOnIntersections ( ) const

inline

Query whether to consider intersections of nearby segments for snapping.

Definition at line 162 of file qgssnappingutils.h.

◆ snapToCurrentLayer()

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

Snap to current layer.

Definition at line 418 of file qgssnappingutils.cpp.

◆ snapToMap() [1/2]

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

Snap to map according to the current configuration (mode).

Optional filter allows discarding unwanted matches.

Definition at line 208 of file qgssnappingutils.cpp.

◆ snapToMap() [2/2]

QgsPointLocator::Match QgsSnappingUtils::snapToMap	(	const QgsPoint &	pointMap,
		QgsPointLocator::MatchFilter *	filter = `nullptr`
	)

Definition at line 219 of file qgssnappingutils.cpp.

◆ snapToMapMode()

SnapToMapMode QgsSnappingUtils::snapToMapMode ( ) const

inline

Find out how the snapping to map is done.

Definition at line 85 of file qgssnappingutils.h.

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

/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgssnappingutils.h
/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgssnappingutils.cpp

Classes

Public Types

Public Slots

Signals

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ IndexingStrategy

◆ SnapToMapMode

Constructor & Destructor Documentation

◆ QgsSnappingUtils()

◆ ~QgsSnappingUtils()

Member Function Documentation

◆ configChanged

◆ currentLayer()

◆ defaultSettings()

◆ dump()

◆ indexingStrategy()

◆ layers()

◆ locatorForLayer()

◆ mapSettings()

◆ prepareIndexProgress()

◆ prepareIndexStarting()

◆ readConfigFromProject

◆ setCurrentLayer()

◆ setDefaultSettings()

◆ setIndexingStrategy()

◆ setLayers()

◆ setMapSettings()

◆ setSnapOnIntersections()

◆ setSnapToMapMode()

◆ snapOnIntersections()

◆ snapToCurrentLayer()

◆ snapToMap() [1/2]

◆ snapToMap() [2/2]

◆ snapToMapMode()