qgspointlocator.h

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/***************************************************************************
  qgspointlocator.h
  --------------------------------------
  Date                 : November 2014
  Copyright            : (C) 2014 by Martin Dobias
  Email                : wonder dot sk at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef QGSPOINTLOCATOR_H
#define QGSPOINTLOCATOR_H

class QgsPointXY;
class QgsVectorLayer;

#include "qgis_core.h"
#include "qgsfeature.h"
#include "qgspointxy.h"
#include "qgscoordinatereferencesystem.h"
#include "qgscoordinatetransform.h"

class QgsPointLocator_VisitorNearestVertex;
class QgsPointLocator_VisitorNearestEdge;
class QgsPointLocator_VisitorArea;
class QgsPointLocator_VisitorEdgesInRect;

namespace SpatialIndex SIP_SKIP
{
  class IStorageManager;
  class ISpatialIndex;
}

class CORE_EXPORT QgsPointLocator : public QObject
{
    Q_OBJECT
  public:

    explicit QgsPointLocator( QgsVectorLayer *layer, const QgsCoordinateReferenceSystem &destinationCrs = QgsCoordinateReferenceSystem(),
                              const QgsCoordinateTransformContext &transformContext = QgsCoordinateTransformContext(),
                              const QgsRectangle *extent = nullptr );

    ~QgsPointLocator() override;

    QgsVectorLayer *layer() const { return mLayer; }

    QgsCoordinateReferenceSystem destinationCrs() const;

    const QgsRectangle *extent() const { return mExtent; }

    void setExtent( const QgsRectangle *extent );

    enum Type
    {
      Invalid = 0, 
      Vertex  = 1, 
      Edge    = 2, 
      Area    = 4, 
      All = Vertex | Edge | Area 
    };

    Q_DECLARE_FLAGS( Types, Type )

    
    bool init( int maxFeaturesToIndex = -1 );

    bool hasIndex() const;

    struct Match
    {
        Match() = default;

        Match( QgsPointLocator::Type t, QgsVectorLayer *vl, QgsFeatureId fid, double dist, const QgsPointXY &pt, int vertexIndex = 0, QgsPointXY *edgePoints = nullptr )
          : mType( t )
          , mDist( dist )
          , mPoint( pt )
          , mLayer( vl )
          , mFid( fid )
          , mVertexIndex( vertexIndex )
        {
          if ( edgePoints )
          {
            mEdgePoints[0] = edgePoints[0];
            mEdgePoints[1] = edgePoints[1];
          }
        }

        QgsPointLocator::Type type() const { return mType; }

        bool isValid() const { return mType != Invalid; }
        bool hasVertex() const { return mType == Vertex; }
        bool hasEdge() const { return mType == Edge; }
        bool hasArea() const { return mType == Area; }

        double distance() const { return mDist; }

        QgsPointXY point() const { return mPoint; }

        int vertexIndex() const { return mVertexIndex; }

        QgsVectorLayer *layer() const { return mLayer; }

        QgsFeatureId featureId() const { return mFid; }

        void edgePoints( QgsPointXY &pt1 SIP_OUT, QgsPointXY &pt2 SIP_OUT ) const
        {
          pt1 = mEdgePoints[0];
          pt2 = mEdgePoints[1];
        }

        bool operator==( const QgsPointLocator::Match &other ) const
        {
          return mType == other.mType &&
                 mDist == other.mDist &&
                 mPoint == other.mPoint &&
                 mLayer == other.mLayer &&
                 mFid == other.mFid &&
                 mVertexIndex == other.mVertexIndex &&
                 mEdgePoints == other.mEdgePoints;
        }

      protected:
        Type mType = Invalid;
        double mDist = 0;
        QgsPointXY mPoint;
        QgsVectorLayer *mLayer = nullptr;
        QgsFeatureId mFid = 0;
        int mVertexIndex = 0; // e.g. vertex index
        QgsPointXY mEdgePoints[2];
    };

#ifndef SIP_RUN
    typedef class QList<QgsPointLocator::Match> MatchList;
#else
    typedef QList<QgsPointLocator::Match> MatchList;
#endif

    struct MatchFilter
    {
      virtual ~MatchFilter() = default;
      virtual bool acceptMatch( const QgsPointLocator::Match &match ) = 0;
    };

    // intersection queries

    Match nearestVertex( const QgsPointXY &point, double tolerance, QgsPointLocator::MatchFilter *filter = nullptr );

    Match nearestEdge( const QgsPointXY &point, double tolerance, QgsPointLocator::MatchFilter *filter = nullptr );

    Match nearestArea( const QgsPointXY &point, double tolerance, QgsPointLocator::MatchFilter *filter = nullptr );

    MatchList edgesInRect( const QgsRectangle &rect, QgsPointLocator::MatchFilter *filter = nullptr );
    MatchList edgesInRect( const QgsPointXY &point, double tolerance, QgsPointLocator::MatchFilter *filter = nullptr );

    // point-in-polygon query

    // TODO: function to return just the first match?
    MatchList pointInPolygon( const QgsPointXY &point );

    //

    int cachedGeometryCount() const { return mGeoms.count(); }

  protected:
    bool rebuildIndex( int maxFeaturesToIndex = -1 );
  protected slots:
    void destroyIndex();
  private slots:
    void onFeatureAdded( QgsFeatureId fid );
    void onFeatureDeleted( QgsFeatureId fid );
    void onGeometryChanged( QgsFeatureId fid, const QgsGeometry &geom );

  private:
    SpatialIndex::IStorageManager *mStorage = nullptr;

    QHash<QgsFeatureId, QgsGeometry *> mGeoms;
    SpatialIndex::ISpatialIndex *mRTree = nullptr;

    bool mIsEmptyLayer;

    QgsCoordinateTransform mTransform;
    QgsVectorLayer *mLayer = nullptr;
    QgsRectangle *mExtent = nullptr;

    friend class QgsPointLocator_VisitorNearestVertex;
    friend class QgsPointLocator_VisitorNearestEdge;
    friend class QgsPointLocator_VisitorArea;
    friend class QgsPointLocator_VisitorEdgesInRect;
};


#endif // QGSPOINTLOCATOR_H