A class that allows advanced snapping operations on a set of vector layers. More...

#include <qgssnapper.h>

Collaboration diagram for QgsSnapper:

Classes
struct	SnapLayer

Public Types
enum	SnappingType { SnapToVertex, SnapToSegment, SnapToVertexAndSegment }
	Snap to vertex, to segment or both. More...

enum	SnappingMode { SnapWithOneResult, SnapWithResultsForSamePosition, SnapWithResultsWithinTolerances }

Public Member Functions
Q_DECL_DEPRECATED	QgsSnapper (QgsMapRenderer *mapRender)
	@ deprecated since 2.4 - use constructor with QgsMapSettings More...

	QgsSnapper (const QgsMapSettings &mapSettings)

	~QgsSnapper ()

int	snapPoint (const QPoint &startPoint, QList< QgsSnappingResult > &snappingResult, const QList< QgsPoint > &excludePoints=QList< QgsPoint >())
	Does the snapping operation. More...

void	setSnapLayers (const QList< QgsSnapper::SnapLayer > &snapLayers)

void	setSnapMode (QgsSnapper::SnappingMode snapMode)

Private Member Functions
void	cleanResultList (QMultiMap< double, QgsSnappingResult > &list, const QList< QgsPoint > &excludeList) const
	Removes the snapping results that contains points in exclude list. More...

Private Attributes
const QgsMapSettings &	mMapSettings
	The map settings object contains information about the output coordinate system of the map and about the relationship between pixel space and map space. More...

QgsSnapper::SnappingMode	mSnapMode
	Snap mode to apply. More...

QList< QgsSnapper::SnapLayer >	mSnapLayers
	List of layers to which snapping is applied. More...

Detailed Description

A class that allows advanced snapping operations on a set of vector layers.

Definition at line 62 of file qgssnapper.h.

Member Enumeration Documentation

enum QgsSnapper::SnappingMode

Enumerator

SnapWithOneResult

Only one snapping result is returned.

SnapWithResultsForSamePosition

Several snapping results which have the same position are returned.

This is useful for topological editing

SnapWithResultsWithinTolerances

All results within the given layer tolerances are returned.

Definition at line 74 of file qgssnapper.h.

enum QgsSnapper::SnappingType

Snap to vertex, to segment or both.

Enumerator
SnapToVertex
SnapToSegment
SnapToVertexAndSegment

Definition at line 66 of file qgssnapper.h.

Constructor & Destructor Documentation

QgsSnapper::QgsSnapper ( QgsMapRenderer * mapRender )

@ deprecated since 2.4 - use constructor with QgsMapSettings

Definition at line 28 of file qgssnapper.cpp.

QgsSnapper::QgsSnapper ( const QgsMapSettings & mapSettings )

explicit

Definition at line 34 of file qgssnapper.cpp.

QgsSnapper::~QgsSnapper ( )

Definition at line 39 of file qgssnapper.cpp.

Member Function Documentation

void QgsSnapper::cleanResultList	(	QMultiMap< double, QgsSnappingResult > &	list,
		const QList< QgsPoint > &	excludeList
	)		const

private

Removes the snapping results that contains points in exclude list.

Definition at line 154 of file qgssnapper.cpp.

References QgsSnappingResult::snappedVertex, and QgsSnappingResult::snappedVertexNr.

Referenced by snapPoint().

void QgsSnapper::setSnapLayers ( const QList< QgsSnapper::SnapLayer > & snapLayers )

Definition at line 143 of file qgssnapper.cpp.

References mSnapLayers.

Referenced by QgsMapCanvasSnapper::snapToBackgroundLayers(), and QgsMapCanvasSnapper::snapToCurrentLayer().

void QgsSnapper::setSnapMode ( QgsSnapper::SnappingMode snapMode )

Definition at line 149 of file qgssnapper.cpp.

References mSnapMode.

Referenced by QgsMapCanvasSnapper::snapToBackgroundLayers(), and QgsMapCanvasSnapper::snapToCurrentLayer().

int QgsSnapper::snapPoint	(	const QPoint &	startPoint,
		QList< QgsSnappingResult > &	snappingResult,
		const QList< QgsPoint > &	excludePoints = `QList<QgsPoint>()`
	)

Does the snapping operation.

Parameters

startPoint	the start point for snapping (in pixel coordinates)
snappingResult	the list where the results are inserted (everything in map coordinate system)
excludePoints	a list with (map coordinate) points that should be excluded in the snapping result. Useful e.g. for vertex moves where a vertex should not be snapped to its original position

Returns: 0 in case of success

Definition at line 44 of file qgssnapper.cpp.

References QgsSnappingResult::afterVertex, QgsSnappingResult::beforeVertex, cleanResultList(), QgsMapSettings::layerToMapCoordinates(), QgsMapSettings::mapToLayerCoordinates(), QgsMapSettings::mapToPixel(), mMapSettings, mSnapLayers, mSnapMode, QgsSnappingResult::snappedVertex, SnapWithOneResult, SnapWithResultsForSamePosition, QgsPoint::sqrDist(), QgsTolerance::toleranceInMapUnits(), and QgsMapToPixel::toMapCoordinates().

Referenced by QgsMapCanvasSnapper::snapToBackgroundLayers(), and QgsMapCanvasSnapper::snapToCurrentLayer().

Member Data Documentation

const QgsMapSettings& QgsSnapper::mMapSettings

private

The map settings object contains information about the output coordinate system of the map and about the relationship between pixel space and map space.

Definition at line 122 of file qgssnapper.h.

Referenced by snapPoint().

QList<QgsSnapper::SnapLayer> QgsSnapper::mSnapLayers

private

List of layers to which snapping is applied.

Definition at line 126 of file qgssnapper.h.

Referenced by setSnapLayers(), and snapPoint().

QgsSnapper::SnappingMode QgsSnapper::mSnapMode

private

Snap mode to apply.

Definition at line 124 of file qgssnapper.h.

Referenced by setSnapMode(), and snapPoint().