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

Public Types
enum	IndexingStrategy { IndexAlwaysFull, IndexNeverFull, IndexHybrid }
enum	SnapToMapMode { SnapCurrentLayer, SnapAllLayers, SnapAdvanced }
	modes for "snap to background" More...

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

Public Member Functions
	QgsSnappingUtils (QObject *parent=0)
	~QgsSnappingUtils ()
QgsVectorLayer *	currentLayer () const
void	defaultSettings (int &type, double &tolerance, QgsTolerance::UnitType &unit)
	query options used when the mode is snap to current layer
IndexingStrategy	indexingStrategy () const
	Find out which strategy is used for indexing - by default hybrid indexing is used.
QList< LayerConfig >	layers () const
	Query layers used for snapping.
QgsPointLocator *	locatorForLayer (QgsVectorLayer *vl)
	get a point locator for the given layer.
const QgsMapSettings &	mapSettings () const
void	setCurrentLayer (QgsVectorLayer *layer)
	set current layer so that if mode is SnapCurrentLayer we know which layer to use
void	setDefaultSettings (int type, double tolerance, QgsTolerance::UnitType unit)
	configure options used when the mode is snap to current layer
void	setIndexingStrategy (IndexingStrategy strategy)
	Set a strategy for indexing geometry data - determines how fast and memory consuming the data structures will be.
void	setLayers (const QList< LayerConfig > &layers)
	Set layers which will be used for snapping.
void	setMapSettings (const QgsMapSettings &settings)
	assign current map settings to the utils - used for conversion between screen coords to map coords
void	setSnapOnIntersections (bool enabled)
	Set whether to consider intersections of nearby segments for snapping.
void	setSnapToMapMode (SnapToMapMode mode)
	Set how the snapping to map is done.
bool	snapOnIntersections () const
	Query whether to consider intersections of nearby segments for snapping.
QgsPointLocator::Match	snapToCurrentLayer (const QPoint &point, int type, QgsPointLocator::MatchFilter *filter=0)
	snap to current layer
QgsPointLocator::Match	snapToMap (const QPoint &point, QgsPointLocator::MatchFilter *filter=0)
	snap to map according to the current configuration (mode).
QgsPointLocator::Match	snapToMap (const QgsPoint &pointMap, QgsPointLocator::MatchFilter *filter=0)
SnapToMapMode	snapToMapMode () const
	Find out how the snapping to map is done.

Protected Member Functions
virtual void	prepareIndexProgress (int index)
	Called when finished indexing a layer. When index == count the indexing is complete.
virtual void	prepareIndexStarting (int count)
	Called when starting to index - can be overridden and e.g. progress dialog can be provided.

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

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.

Definition at line 86 of file qgssnappingutils.h.

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 74 of file qgssnappingutils.h.

Constructor & Destructor Documentation

QgsSnappingUtils::QgsSnappingUtils ( QObject * parent = 0 )

Definition at line 24 of file qgssnappingutils.cpp.

QgsSnappingUtils::~QgsSnappingUtils ( )

Definition at line 37 of file qgssnappingutils.cpp.

Member Function Documentation

QgsVectorLayer* QgsSnappingUtils::currentLayer ( ) const

inline

Definition at line 68 of file qgssnappingutils.h.

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

query options used when the mode is snap to current layer

Definition at line 373 of file qgssnappingutils.cpp.

IndexingStrategy QgsSnappingUtils::indexingStrategy ( ) const

inline

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

Definition at line 96 of file qgssnappingutils.h.

QList<LayerConfig> QgsSnappingUtils::layers ( ) const

inline

Query layers used for snapping.

Definition at line 116 of file qgssnappingutils.h.

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 43 of file qgssnappingutils.cpp.

const QgsMapSettings& QgsSnappingUtils::mapSettings ( ) const

inline

Definition at line 64 of file qgssnappingutils.h.

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 131 of file qgssnappingutils.h.

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 129 of file qgssnappingutils.h.

void QgsSnappingUtils::readConfigFromProject ( )

slot

Read snapping configuration from the project.

Definition at line 386 of file qgssnappingutils.cpp.

void QgsSnappingUtils::setCurrentLayer ( QgsVectorLayer * layer )

inline

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

Definition at line 67 of file qgssnappingutils.h.

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

configure options used when the mode is snap to current layer

Definition at line 362 of file qgssnappingutils.cpp.

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 94 of file qgssnappingutils.h.

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

inline

Set layers which will be used for snapping.

Definition at line 114 of file qgssnappingutils.h.

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 352 of file qgssnappingutils.cpp.

void QgsSnappingUtils::setSnapOnIntersections ( bool enabled )

inline

Set whether to consider intersections of nearby segments for snapping.

Definition at line 119 of file qgssnappingutils.h.

void QgsSnappingUtils::setSnapToMapMode ( SnapToMapMode mode )

inline

Set how the snapping to map is done.

Definition at line 82 of file qgssnappingutils.h.

bool QgsSnappingUtils::snapOnIntersections ( ) const

inline

Query whether to consider intersections of nearby segments for snapping.

Definition at line 121 of file qgssnappingutils.h.

QgsPointLocator::Match QgsSnappingUtils::snapToCurrentLayer	(	const QPoint &	point,
		int	type,
		QgsPointLocator::MatchFilter *	filter = `0`
	)

snap to current layer

Definition at line 335 of file qgssnappingutils.cpp.

QgsPointLocator::Match QgsSnappingUtils::snapToMap	(	const QPoint &	point,
		QgsPointLocator::MatchFilter *	filter = `0`
	)

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

Optional filter allows to discard unwanted matches.

Definition at line 202 of file qgssnappingutils.cpp.

QgsPointLocator::Match QgsSnappingUtils::snapToMap	(	const QgsPoint &	pointMap,
		QgsPointLocator::MatchFilter *	filter = `0`
	)

Definition at line 207 of file qgssnappingutils.cpp.

SnapToMapMode QgsSnappingUtils::snapToMapMode ( ) const

inline

Find out how the snapping to map is done.

Definition at line 84 of file qgssnappingutils.h.

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

/tmp/buildd/qgis-2.8.2+12wheezy/src/core/qgssnappingutils.h
/tmp/buildd/qgis-2.8.2+12wheezy/src/core/qgssnappingutils.cpp

Classes

Public Types

Public Slots

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation