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 retured*/
      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;
    };

    QgsSnapper( QgsMapRenderer* mapRender );
    ~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*/
    int snapPoint( const QPoint& startPoint, QList<QgsSnappingResult>& snappingResult /Out/, const QList<QgsPoint>& excludePoints = QList<QgsPoint>() );

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

};