qgssnappingutils.h

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/***************************************************************************
  qgssnappingutils.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 QGSSNAPPINGUTILS_H
#define QGSSNAPPINGUTILS_H


#include "qgsmapsettings.h"
#include "qgstolerance.h"
#include "qgspointlocator.h"

class CORE_EXPORT QgsSnappingUtils : public QObject
{
    Q_OBJECT
  public:
    QgsSnappingUtils( QObject* parent = 0 );
    ~QgsSnappingUtils();

    // main actions

    QgsPointLocator* locatorForLayer( QgsVectorLayer* vl );

    QgsPointLocator::Match snapToMap( const QPoint& point, QgsPointLocator::MatchFilter* filter = 0 );
    QgsPointLocator::Match snapToMap( const QgsPoint& pointMap, QgsPointLocator::MatchFilter* filter = 0 );

    QgsPointLocator::Match snapToCurrentLayer( const QPoint& point, int type, QgsPointLocator::MatchFilter* filter = 0 );

    // environment setup

    void setMapSettings( const QgsMapSettings& settings );
    const QgsMapSettings& mapSettings() const { return mMapSettings; }

    void setCurrentLayer( QgsVectorLayer* layer ) { mCurrentLayer = layer; }
    QgsVectorLayer* currentLayer() const { return mCurrentLayer; }


    // configuration

    enum SnapToMapMode
    {
      SnapCurrentLayer,    
      SnapAllLayers,       
      SnapAdvanced,        
    };

    void setSnapToMapMode( SnapToMapMode mode ) { mSnapToMapMode = mode; }
    SnapToMapMode snapToMapMode() const { return mSnapToMapMode; }

    enum IndexingStrategy
    {
      IndexAlwaysFull,    
      IndexNeverFull,     
      IndexHybrid         
    };

    void setIndexingStrategy( IndexingStrategy strategy ) { mStrategy = strategy; }
    IndexingStrategy indexingStrategy() const { return mStrategy; }

    void setDefaultSettings( int type, double tolerance, QgsTolerance::UnitType unit );
    void defaultSettings( int& type, double& tolerance, QgsTolerance::UnitType& unit );

    struct LayerConfig
    {
      LayerConfig( QgsVectorLayer* l, int t, double tol, QgsTolerance::UnitType u ) : layer( l ), type( t ), tolerance( tol ), unit( u ) {}

      QgsVectorLayer* layer;
      int type;
      double tolerance;
      QgsTolerance::UnitType unit;
    };

    void setLayers( const QList<LayerConfig>& layers ) { mLayers = layers; }
    QList<LayerConfig> layers() const { return mLayers; }

    void setSnapOnIntersections( bool enabled ) { mSnapOnIntersection = enabled; }
    bool snapOnIntersections() const { return mSnapOnIntersection; }

  public slots:
    void readConfigFromProject();

  protected:
    virtual void prepareIndexStarting( int count ) { Q_UNUSED( count ); }
    virtual void prepareIndexProgress( int index ) { Q_UNUSED( index ); }

  private slots:
    void onLayersWillBeRemoved( QStringList layerIds );

  private:
    const QgsCoordinateReferenceSystem* destCRS();

    void clearAllLocators();

    QgsPointLocator* locatorForLayerUsingStrategy( QgsVectorLayer* vl, const QgsPoint& pointMap, double tolerance );
    QgsPointLocator* temporaryLocatorForLayer( QgsVectorLayer* vl, const QgsPoint& pointMap, double tolerance );

    bool willUseIndex( QgsVectorLayer* vl ) const;
    void prepareIndex( const QList<QgsVectorLayer*>& layers );

  private:
    // environment
    QgsMapSettings mMapSettings;
    QgsVectorLayer* mCurrentLayer;

    // configuration
    SnapToMapMode mSnapToMapMode;
    IndexingStrategy mStrategy;
    int mDefaultType;
    double mDefaultTolerance;
    QgsTolerance::UnitType mDefaultUnit;
    QList<LayerConfig> mLayers;
    bool mSnapOnIntersection;

    // internal data
    typedef QMap<QgsVectorLayer*, QgsPointLocator*> LocatorsMap;
    LocatorsMap mLocators;
    LocatorsMap mTemporaryLocators;
    QSet<QString> mHybridNonindexableLayers;
};


#endif // QGSSNAPPINGUTILS_H