QGIS/python/core/qgssnapper.sip

/** Describes the result of a snapping operation*/
struct QgsSnappingResult
{
%TypeHeaderCode
#include <qgssnapper.h>
%End

  /** The coordinates of the snapping result*/
  QgsPoint snappedVertex;
  /** The vertex index of snappedVertex
   or -1 if no such vertex number (e.g. snap to segment)*/
  int snappedVertexNr;
  /** The layer coordinates of the vertex before snappedVertex*/
  QgsPoint beforeVertex;
  /** The index of the vertex before snappedVertex
   or -1 if no such vertex*/
  int beforeVertexNr;
  /** The layer coordinates of the vertex after snappedVertex*/
  QgsPoint afterVertex;
  /** The index of the vertex after snappedVertex
   or -1 if no such vertex*/
  int afterVertexNr;
  /** Index of the snapped geometry*/
  qint64 snappedAtGeometry;
  /** Layer where the snap occured*/
  const QgsVectorLayer* layer;
};



/** A class that allows advanced snapping operations on a set of vector layers*/
class QgsSnapper
{
%TypeHeaderCode
#include <qgssnapper.h>
%End

  public:
    /** Snap to vertex, to segment or both*/
    enum SnappingType
    {
      SnapToVertex,
      SnapToSegment,
      //snap to vertex and also to segment if no vertex is within the search tolerance
      SnapToVertexAndSegment
    };

    enum SnappingMode
    {
      /** Only one snapping result is returned*/
      SnapWithOneResult,
      /** Several snapping results which have the same position are returned.
         This is useful for topological editing*/
      SnapWithResultsForSamePosition,
      /** All results within the given layer tolerances are returned*/
      SnapWithResultsWithinTolerances
    };

    struct SnapLayer
    {
      /** The layer to which snapping is applied*/
      QgsVectorLayer* mLayer;
      /** The snapping tolerances for the layers, always in source coordinate systems of the layer*/
      double mTolerance;
      /** What snapping type to use (snap to segment or to vertex)*/
      QgsSnapper::SnappingType mSnapTo;
      /** What unit is used for tolerance*/
      QgsTolerance::UnitType mUnitType;
    };

    //!@ deprecated since 2.4 - use constructor with QgsMapSettings
    QgsSnapper( QgsMapRenderer *mapRender ) /Deprecated/;

    explicit QgsSnapper( const QgsMapSettings& mapSettings );

    ~QgsSnapper();

    /** Does the snapping operation
     @param startPoint the start point for snapping (in pixel coordinates)
     @param snappingResult the list where the results are inserted (everything in map coordinate system)
     @param 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
     @return 0 in case of success
     @deprecated
     */
    int snapPoint( const QPoint &startPoint, QList<QgsSnappingResult> &snappingResult /Out/, const QList<QgsPoint> &excludePoints = QList<QgsPoint>() ) /Deprecated/;

    /** Does the snapping operation
     @param mapCoordPoint the start point for snapping (in map coordinates)
     @param snappingResult the list where the results are inserted (everything in map coordinate system)
     @param 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
     @return 0 in case of success
    */
    int snapMapPoint( const QgsPoint &mapCoordPoint, QList<QgsSnappingResult> &snappingResult /Out/, const QList<QgsPoint> &excludePoints = QList<QgsPoint>() );

    //setters
    void setSnapLayers( const QList<QgsSnapper::SnapLayer>& snapLayers );
    void setSnapMode( QgsSnapper::SnappingMode snapMode );

};