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
	QgsSnapper (QgsMapRenderer *mapRender)
	~QgsSnapper ()
int	snapPoint (const QPoint &startPoint, QList< QgsSnappingResult > &snappingResult, const QList< QgsPoint > &excludePoints=QList< QgsPoint >())
	Does the snapping operation.
void	setSnapLayers (const QList< QgsSnapper::SnapLayer > &snapLayers)
void	setSnapMode (QgsSnapper::SnappingMode snapMode)

Private Member Functions
	QgsSnapper ()
	Don't use the default constructor.
void	cleanResultList (QMultiMap< double, QgsSnappingResult > &list, const QList< QgsPoint > &excludeList) const
	Removes the snapping results that contains points in exclude list.

Private Attributes
QgsMapRenderer *	mMapRenderer
	The maprender object contains information about the output coordinate system of the map and about the relationship between pixel space and map space.
QgsSnapper::SnappingMode	mSnapMode
	Snap mode to apply.
QList< QgsSnapper::SnapLayer >	mSnapLayers
	List of layers to which snapping is applied.

Detailed Description

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

Definition at line 61 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 73 of file qgssnapper.h.

enum QgsSnapper::SnappingType

Snap to vertex, to segment or both.

Enumerator:

SnapToVertex
SnapToSegment
SnapToVertexAndSegment

Definition at line 65 of file qgssnapper.h.

Constructor & Destructor Documentation

QgsSnapper::QgsSnapper ( QgsMapRenderer * mapRender )

Definition at line 27 of file qgssnapper.cpp.

QgsSnapper::~QgsSnapper ( )

Definition at line 37 of file qgssnapper.cpp.

QgsSnapper::QgsSnapper ( )

private

Don't use the default constructor.

Definition at line 32 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 135 of file qgssnapper.cpp.

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

Referenced by snapPoint().

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

Definition at line 124 of file qgssnapper.cpp.

References mSnapLayers.

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

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

Definition at line 130 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