qgstracer.h

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/***************************************************************************
 qgstracer.h
 --------------------------------------
 Date                 : January 2016
 Copyright            : (C) 2016 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 QGSTRACER_H
#define QGSTRACER_H

class QgsVectorLayer;

#include "qgis_core.h"
#include <QSet>
#include <QVector>
#include <memory>

#include "qgsfeatureid.h"
#include "qgscoordinatereferencesystem.h"
#include "qgsrectangle.h"
#include "qgsgeometry.h"

struct QgsTracerGraph;
class QgsFeatureRenderer;
class QgsRenderContext;

class CORE_EXPORT QgsTracer : public QObject
{
    Q_OBJECT
  public:

    QgsTracer();
    ~QgsTracer() override;

    QList<QgsVectorLayer *> layers() const { return mLayers; }
    void setLayers( const QList<QgsVectorLayer *> &layers );

    QgsCoordinateReferenceSystem destinationCrs() const { return mCRS; }

    void setDestinationCrs( const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context );

    void setRenderContext( const QgsRenderContext *renderContext );

    QgsRectangle extent() const { return mExtent; }
    void setExtent( const QgsRectangle &extent );

    double offset() const { return mOffset; }

    void setOffset( double offset );

    void offsetParameters( int &quadSegments SIP_OUT, int &joinStyle SIP_OUT, double &miterLimit SIP_OUT );

    void setOffsetParameters( int quadSegments, int joinStyle, double miterLimit );

    int maxFeatureCount() const { return mMaxFeatureCount; }
    void setMaxFeatureCount( int count ) { mMaxFeatureCount = count; }

    bool init();

    bool isInitialized() const { return static_cast< bool >( mGraph ); }

    bool hasTopologyProblem() const { return mHasTopologyProblem; }

    enum PathError
    {
      ErrNone,               
      ErrTooManyFeatures,    
      ErrPoint1,             
      ErrPoint2,             
      ErrNoPath,             
    };

    QVector<QgsPointXY> findShortestPath( const QgsPointXY &p1, const QgsPointXY &p2, PathError *error SIP_OUT = nullptr );

    bool isPointSnapped( const QgsPointXY &pt );

  protected:

    virtual void configure() {}

  protected slots:
    void invalidateGraph();

  private:
    bool initGraph();

  private slots:
    void onFeatureAdded( QgsFeatureId fid );
    void onFeatureDeleted( QgsFeatureId fid );
    void onGeometryChanged( QgsFeatureId fid, const QgsGeometry &geom );
    void onAttributeValueChanged( QgsFeatureId fid, int idx, const QVariant &value );
    void onDataChanged( );
    void onStyleChanged( );
    void onLayerDestroyed( QObject *obj );

  private:
    std::unique_ptr< QgsTracerGraph > mGraph;
    QList<QgsVectorLayer *> mLayers;
    QgsCoordinateReferenceSystem mCRS;
    QgsCoordinateTransformContext mTransformContext;
    std::unique_ptr<QgsRenderContext> mRenderContext;
    QgsRectangle mExtent;

    double mOffset = 0;
    int mOffsetSegments = 8;
    int mOffsetJoinStyle = 2;
    double mOffsetMiterLimit = 5.;

    int mMaxFeatureCount = 0;

    bool mHasTopologyProblem = false;
};


#endif // QGSTRACER_H